Upload
others
View
18
Download
0
Embed Size (px)
Citation preview
A S S E M B LY I N S T R U C T I O N SWith loads of helpful tips!
Famously clean withenough guts to gig!
’66 D-REVERB 22W C O M B O A M P K I T ORIGINAL AB763 CIRCUIT
stewmac.com 2 © 2019 StewMac
Contents
About this iconic amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Tools and supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Amp voltages are seriously dangerous! . . . . . . . . . . . . . . . . . . . . . . . . . . 6
How to use a snuffer stick . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
How to read resistor values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Capacitor values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Prepping the cabinet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Prepping the eyelet boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Tips for great soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Installing the chassis-mounted components . . . . . . . . . . . . . . . . . . . 13
How to install parts on an eyelet board in three steps . . . . . . . . . . 22
Wrapping parts onto the bias board . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Wrapping parts onto the filter cap board . . . . . . . . . . . . . . . . . . . . . . . 25
Wrapping parts onto the main eyelet board . . . . . . . . . . . . . . . . . . . . 27
Installing parts and preparing for testing . . . . . . . . . . . . . . . . . . . . . . 52
Testing and troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Final assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Tips for using the 66D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Learning more: secrets revealed in the schematic . . . . . . . . . . . . . . 58
Circuit schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
More iconic amp kits from StewMac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Complete wiring diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Tube replacement chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
COPYRIGHT WARNINGThis material is protected by copyright and has been created by and solely for the purposes of StewMac . You may not sell, alter or further reproduce any part of this material, or distribute it to any other per-son . Where provided to you in electronic format, you may only print from it for your own private use . Failure to comply with the terms of this warning exposes you to legal action for copyright infringement .
How to build this kit!
stewmac.com 1 © 2019 StewMac
’66 D-REVERB 22W COMBO AMP KIT ORIGINAL AB763 CIRCUIT
For many players, this is the #1 desert island amp!
Be excited!Your new StewMac ’66 D-Reverb will be a blast to play through and even more fun to build .
Perfect for recording as well as performing, the D-Reverb produces stinging clarity that absolutely refuses to get lost in the mix .
This amp is an ICONOne of the most popular designs ever, this amp lives in the happy middle between bright clarity and rich distortion . It excels in the studio and on the stage . While capable of crystal clear tones at good volume, you can push this one into beautifully saturated, play-sensitive distortion .
It’s all here: clarity, distortion, and rectifier tube sag .
StewMac ICON KITS bring classics that are no longer made, or are simply unaffordable, within reach . And the best part is you get to build them with your own hands .
We give painstaking attention to parts selection, authentic materials, and instantly recognizable details—everything that makes the originals so sought after .
Build it with StewMacThese immersive instructions walk you through every step of creating your ’66 D-Reverb . And you’ll learn a lot, gaining a deep knowledge of your amp’s inner workings .
Follow our steps closely for safety, too: we’ve carefully laid out a path that even newcomers can follow in handling electrical components .
Building an amp can seem daunting, but nobody makes it easier than StewMac . Watch for helpful tips along the way, too—we’re here to help!
Let’s get building!
stewmac.com 2 © 2019 StewMac
Here’s how to build this amp!
Wiring goes like this:1. First, you’ll wrap the leads, connecting them without solder. 2. Then double-check all the connections. Don’t rush!3. When everything checks out, it's time to solder. The numbered steps tell you when.
Get the cabinet ready, starting at Step 1 on page 8.You’ll prep the metal chassis and the eyelet board too.
Learn more:You don’t need to read the schematic, but it’s fun! See how your guitar’s signal gets processed into sound on page 59.
Sort your components by type, using the parts list.Quick look:
See page 11
#10733 © 2018 StewMac
GroundJackTransformer Preamp tube
plategrid
cathode
Power tube
grid
plate
cathode
screen
Capacitor
Electrolytic Cap.
DiodeResistor Potentiometers Rectifier tube Optoisolater
plate cathode
filamentplate
Shieldedcable
’66 D-REVERB 22WORIGINAL AB763 CIRCUIT
Gain GainProcessing
Processing
Processing
Output
Power
Negative Feedback
68K
25μF
50V
25μF
50V
25μF
50V
1.5K
6.8K
68K
B
B D
2
2
6+180V
6+180V
+1.3V 8
+1.3V 8
8+1.3V
+200V
1
+77V
250pF
10p
F
.1p
F
.01μ
F
.047μF
.022μF
.0033μF
.01μF
AE
C
BC
VIBRATOPEDAL
REVERBPEDAL
REVERB UNITOutputInput
.1μF .01μF
.1μF
.1μF
SOCKET V1
7025 SOCKET V4
7025
NO
RM
AL
SOCKET V3
12AT7
SOCKET V9
GZ34
SOCKET V5
12AX7
SOCKET V6
12AT7
SOCKET V7
6V6GT
SOCKET V8
6V6GT
.1μF
500pF
.047μF1 10
0K
100K
100K
100Ω
100Ω
82K
220K
220K
220K
47Ω
1M1M
100K
3.3M
220K
22K
1.5K
470Ω
820Ω
470Ω
470Ω1.5K
10K10K
100K
220K
100K
100K
100K
100K
100K
470K
220K
2.2M 22
0K
10M
10K
470Ω
250K
ATR
EBLE
1 MA
VO
LUM
E
250K
AB
ASS
3MRASPEED
50KR
AIN
TEN
SITY
68K
25μF
50V
1.5K
25μF
50V
820Ω
6.8K
68K
1M1M
2
2
+170V 1
+180V 1
3 +1.3V
3 +1.3V
+170V6
+180V6
250pF 47pF
A
.1μF
SOCKET V2
7025
VIB
RA
TO
.047μF1
100K
250K
ATR
EBLE
100K
LR
EVER
B
1 MA
VO
LUM
E
250K
AB
ASS
7 EXTENSIONSPEAKER
TR3
TR2
STANDBYSWITCH
TR4
TR1
TR1: 125P33A 125P23B TR2: 125C3ATR3: 125A1ATR4: 125A20B
8
8
5
6 8
4 2
3 +1.2V
+170V11
2 2
+410V
6
8 +8.7V
3 +370V
3 +415V
-35V
+41
5V
2.2K
1M
330VACAC switch
1 ampslow-blow fuse
To tube heaters and pilot light
330VAC
820Ω
25μF
50V
16μF
450V
16μF
450V
25μF
50V
27K
25μF
50V
100A
K
.02μ
F
16μF
450V
16μF
450V
D 16μF
450V
1M
1M10KL
2 1
3
6
7
8
7
7
2
8
5
4 +365V
4 +415V
OutputGain Processing
stewmac.com 3 © 2019 StewMac
Resistors
r (1) 47Ω .5W carbon composite
r (2) 100Ω .5W carbon composite
r (1) 470Ω .5W carbon composite
r (3) 820Ω .5W carbon composite
r (4) 1.5K .5W carbon composite
r (1) 2.2K .5W carbon composite
r (1) 2.7K .5W carbon composite
r (2) 6.8K .5W carbon composite
r (1) 10K .5W carbon composite
r (1) 22K .5W carbon composite
r (1) 27K .5W carbon composite
r (1) 56K .5W carbon composite
r (4) 68K .5W carbon composite
r (1) 82K .5W carbon composite
r (12)100K .5W carbon composite
r (8) 220K .5W carbon composite
r (1) 470K .5W carbon composite
r (7) 1M .5W carbon composite
r (1) 2.2M .5W carbon composite
r (1) 3.3M .5W carbon composite
r (3) 470Ω 1W carbon film
r (1) 10M 1W carbon film
r (2) 10K 2W metal oxide
Yellow Violet Black Gold
Brown Black Brown Gold
Yellow Violet Brown Gold
Brown Green Red Gold
Gray Red Brown Gold
Red Red Red Gold
Red Violet Orange Gold
Red Violet Red Gold
Blue Gray Red Gold
Red Red Green Gold
Orange Orange Green Gold
Red Red Orange Gold
Green Blue Orange Gold
Blue Gray Orange Gold
Gray Red Orange Gold
Brown Black Yellow Gold
Brown Black Orange Gold
Red Red Yellow Gold
Yellow Violet Yellow Gold
Brown Black Green Gold
Yellow Violet Brown Gold
Brown Black Blue Gold
Brown Black Orange Gold
Capacitors
r (1) 47pF 500V silver mica
r (2) 250pF 500V silver mica
r (1) 500pF 500V silver mica
r (1) 10pF 500V ceramic disk
r (2) .01μF 500V ceramic disk
r (1) .02μF 500V ceramic disk
r (1) .001μF 600V Orange Drop
r (1) .0033μF 600V Orange Drop
r (1) .022μF 600V Orange Drop
r (4) .047μF 600V Orange Drop
r (6) .1μF 600V Orange Drop
r (5) 16μF 500V electrolytic
r (8) 25μF 50V sprague atom
Diode, optoisolator
r (1) 1N4007 1000V rectifier diode
r (1) Optoisolator
250
102J 1119
+
25µF
510+47
332J 600V
223J 600V
473J 600V
104J 600V
16μF
103K
203Z
r (1) Cabinet
r (1) Chassis
r (1) Capacitor pan
r (3) Eyelet boards
r (3) Insulator boards
r (1) Faceplate/backplate set
r (1) 12” speaker
Hardware
r (6) 8-32 machine screw, 3/8"r (10) 8-32 locknut
r (4) 6-32 machine screw, 1/2"r (4) 6-32 locknut
r (6) 4-40 machine screw, 3/8"r (20) 4-40 machine screw, 1/4"r (26) 4-40 locknut
r (4) Self-tapping screw
r (1) Black wood screw
r (1) Power cord clamp
r (1) Strain relief for power cord
r (6) Rubber grommet
r (2) Chassis mounting strapr (4) Chassis strap screw and nut
Parts list
stewmac.com 4 © 2019 StewMac
12AX
712AT7
6V6
5AR
4
4
3 2
18
76
5
6
4 3 21
987
5
Tubes, lamps, fuses, and sockets
r (4) RCA-style jack
r (1) Two-lug jack
r (5) Three-lug jack
r (6) Nine-pin tube socket
r (6) Shield for nine-pin tube socket
r (3) Eight-pin tube socket
r (3) Tension clip for eight-pin socket
r (4) 12AX7 preamp tube (also called ECC83S)
r (2) 12AT7 preamp tube (also called ECC81)
r (2) 6V6S power tube
r (1) 5AR4 rectifier tube (also called GZ34)
r (1) Fuse socket
r (1) Fuse (1 amp, slow blow)
r (1) Pilot lamp socket with lens
r (1) Pilot lamp bulb (#47)
Control pots and more
r (1) 10KL bias pot
r (1) 100KL control pot
r (4) 250KA control pot
r (2) 1MA control pot
r (1) 3MRA control pot
r (1) 50KRA control pot
r (9) Knob
r (2) Three-lug grounding strip
r (2) Power switch (2 lugs)
r (1) Ground switch (3 lugs)
r (1) Power cord
r (1) Speaker plug
Transformers
r (1) Power transformer
r (1) Output transformer
r (1) Reverb driver
r (1) Filter choke
Reverb
r (1) Reverb tank
r (1) Reverb tank bag
r (1) Reverb wiring kit
r (1) Footswitch
10
0KL
25
0KA
1MA
3MRA
50
KRA
1234
10
56
7 8 9
10KL
Wire
r (1) Heater wires (pre-tinned)
r (1) Speaker wires (multi-strand)
r (1) Yellow push-back wire
r (1) Green push-back wire
Heat-shrink tubing
r (2) 1/8" diameter
Vintage-style push-back wire lets you push the insulation back instead of trimming it. BUT: Trimming it still works better!
Parts list
stewmac.com 5 © 2019 StewMac
#0531 StewMac Solder Monster
#3000 Guitar Tech Screwdriver Set
#1606 Wire Stripper
#1607 Wire Cutter
#0501 Solomon SL-30 Soldering Station
#1609 Round Nose Bending Pliers #0505
Kester Pocket-Pak Solder
StewMac’s Solder Monster holds parts while you solder
Tools and supplies
Required Phillips screwdrivers, #1 and #2 Item #3000 Guitar Tech Screwdriver Set
Needle nose pliers Item #1610 Long Nose Pliers
Wire cutter Item #1607 Wire Cutter
Wire stripper Item #1606 Wire Stripper
Soldering iron (preferably 40W) Item #0501 Solomon SL-30 Soldering Station
Solder (at least one Pocket-Pak) Item #0505 Kester Pocket-Pak Solder
Solder sucker Item #0503 Solomon Solder Sucker
Drill with a 5/32", 5/64", and 1/4" bit For mounting eyelet board and filter cap
Ruler Item #4905 StewMac Shop Rule
Digital multimeter Item #3618 Fieldpiece Pocket Multimeter
Snuffer stick (bleed resistor) Item #1552 Snuffer Stick
Pencil Wooden chopsticks Glue Wood glue, white glue, or contact cement for gluing a paper label inside the cabinet
Butane lighter or matches For heating heat-shrink tubing
Helpful Round nose bending pliers Item #1609 Round Nose Bending Pliers
Solder wick Item #0504 Solder Wick, 5-foot roll
Soldering aids Item #0521 StewMac Soldering Aids
Soldering stand Item #0506 Solomon Soldering Stand
Solder Monster, or helping hand tool Item #0531 StewMac Solder Monster
Chassis stand Item #10750 Chassis Stand
Printed circuit board vise Scratch awl or center punch Item #3000 Guitar Tech Screwdriver Set
Tray for loose parts Bias meter for accurate biasing Item #1580 VHT Tube Tester + Amp Bias Meter
stewmac.com 6 © 2019 StewMac
High voltage, even when unpluggedWhen you turn on an amp, the capacitors are designed to take on a charge and hold it . That stored voltage is enough to injure you seriously, or even kill you .
These components aren’t a threat until the first time you plug the amp in . The stored electricity can be safely discharged to ground with a snuffer stick . See how to use it below .
Once your amp has been turned on, don’t touch the wiring with your bare hands—even after turning it off . If you need to press on a contact, use a chopstick or Sharpie marker, which are both non-conductive . Don’t use a pencil, because graphite is conductive .
It’s important that you understand the dangers so you’re working safely . Here’s how to do it right .
Wear rubber-soled shoesRubber soles increase the insulation between yourself and the ground .
Take off your ringA metal ring on your finger can bridge a hot connection to ground .
Wear safety glassesRosin-core solder sometimes bubbles up, and it can spew molten specks into the air . You don’t want molten solder in your eyes .
It’s better not to work aloneElectrical shocks can incapacitate you, and having someone available to call 911 can be a lifesaver .
How to use a snuffer stickTo discharge a capacitor, clip the snuffer stick lead to ground—preferably a mounting bolt on the power transformer . Hold the tip of the stick to the cap’s positive lead and use your multimeter to watch the voltage drain to less than 18V .
Take breaks and stop when you’re tiredFatigue leads to mistakes, and no one can afford mistakes when working with electricity .
Stay suspiciousWhether it’s the first time you’ve been inside a live ampli-fier or the 100th time, don’t become complacent . If you discharge the caps and walk away for a few minutes, check again for residual voltage when you return . Capacitors can self-charge through a phenomenon known as dielectric memory .
Check before powering on It’s easy to forget that you a left a stray tool or wire in the chassis . It’s also easy to forget to re-attach the speaker wire, and that can fry an output transformer in seconds . Constant vigilance is your friend when working on amps .
Always unplug itUnplug the amp whenever you don’t specifically need it plugged in . Some points are always hot when the amp’s plugged in, even if the power switch is off . These points include the lugs on the fuse socket, power switch, and standby switch .
Amp voltages are seriously dangerous!
Professionals who work on amps take these safety habits very seriously
stewmac.com 7 © 2019 StewMac
A resistor’s value—the amount of resistance it creates—is rated in ohms (Ω) . Larger ohm values mean more resistance . For example, a 100Ω resistor creates ten times as much re-sistance as a 10Ω resistor .
The resistors used in amplifiers are too small to have value numbers printed on them . Instead, a system of colored bands tells their values . The key to reading these bands is provided below . However, an easier way to decode these bands is to download one of the many smartphone apps for this purpose .
One band will be the nearest to an end of the resistor . That band tells the first value . Combine it with the value of band 2 to get a two-digit number (68 in our example below) . Multiply that number by band 3 (68 x 1,000 = 68,000) . Thou-sands are represented by the letter K, so this resistor is 68K (kilo-ohms, or KΩ) .
If there is a fourth band, it will be either silver or gold . This indicates the tolerance allowed during manufacturing . The resistors used in this kit have a +/- 5% tolerance, represented by a gold band 4 .
A magnifying glass helps a lot . The bands on a 470Ω resistor are yellow/violet/brown, and the bands on a 47K resistor are yellow/violet/orange . They’re easily confused!
Can’t read the colors?You can always use a multimeter to test a resistor’s value . Set your meter to ohms and connect the test leads on each side of the resistor .
Capacitor values are typically printed on the component . The key values with caps are their capacitance and voltage .
Think of a capacitor as a container that can hold electricity . Capacitance, measured in farads, refers to how much elec-tricity this container can hold—its capacity . One farad (1F) would be much too large for use in an amplifier . Caps for amps are rated in millionths of a farad, called microfarads (μF), or trillionths of a farad: picofarads (pF) . The voltage spec for a cap refers to how much DC voltage it can handle at any given time .
A unique property of capacitors is that they don’t allow DC current to flow past them, only AC current . This is important in parts of an amplifier circuit, such as the path between a preamp stage and a power amp stage . Here, a “coupling capacitor" will block DC voltage, allowing only the AC guitar signal to pass .
Filter capsCapacitors also filter out 60Hz hum, or “ripple," after the AC current from the wall is converted to DC . These capacitors are called filter caps, because they filter out the ripple from a power supply . The filter caps in this amp are the 16μF electrolytic capacitors .
Electrolytic capsElectrolytic capacitors contain electrolyte: a liquid or gel that gives them a large storage capacity . Electrolytic caps are typically polarized .
Polarized capsSome capacitors have polarity and some don’t . It’s extremely important to install polarized caps correctly in a circuit . The positive lead of an electrolytic cap will be indicated by an indented ring around one edge of the capacitor . The nega-tive lead will often be indicated by a band of arrows pointing to the negative lead .
Installing capacitors with the polarity backwards will make the circuit malfunction and quickly destroy the capacitor—even causing it to explode .
Band 1 Band 2 Band 3 Band 4 1st Digit 2nd Digit Multiplier Tolerance
6 8 x1,000 +/- 5%
68K +/- 5%K = 1,000
Blue
Read this band first (closest to an end)
Gray Orange Gold
BLACK 0 0 1 None +/- 20%
BROWN 1 1 10
RED 2 2 100
ORANGE 3 3 1,000
YELLOW 4 4 10,000
GREEN 5 5 100,000
BLUE 6 6 1,000,000
VIOLET 7 7
GRAY 8 8 0.01 +/- 10% SILVER
WHITE 9 9 0.1 +/- 5% GOLD
NegativePositive
+ 25μF
16μf
How to read resistor values Capacitor values
stewmac.com 8 © 2019 StewMac
STEP 2
Solder the speaker plugUse a small screwdriver to remove the back panel of the speaker plug .
On the black and white speaker leads, push the insulation back 3/8" . Solder the white positive lead to the tip lug (center of the plug) .
Trim the black lead and solder it to the sleeve lug . The solder joints need to be neat so they won’t short against the metal case . See "Tips for great soldering" on page 11 .
Reassemble the plug and do a continuity test with your multimeter to make sure there’s no connection between the plug’s tip and its metal case (see page 53) .
Remove the cabinet’s two back panels to prepare for installing the speaker .
STEP 1
Mount the power cord clampDrill a 5/64" pilot hole to mount the power cord clamp . Locate the clamp inside the left wall of the cabinet, 1” f rom the back panel ledge, 8” from the bottom .
Don’t drill through the cabinet! Use a piece of masking tape on your drill bit to mark the depth, or use a StewMac Depth-stop Drill Bit (item #1712) .
Use the black wood screw to mount the power cord clamp . You’ll secure the power cord with this clamp later, after the testing .
Start by prepping the cabinet
STEP 3
Solder the speaker leadsTwist the speaker leads together to keep them neat .
Push the insulation back 3/8" and insert the white lead into the speaker’s positive terminal and the black lead through the negative terminal .
Before soldering these leads, place a business card or other protection under the terminals to prevent solder dripping onto the speaker cone . Solder the two leads to the speaker terminals .
Check off eachcompleted step
Back
Here
stewmac.com 9 © 2019 StewMac
STEP 5
Install faceplate + backplateSecure the faceplate by putting the normal channel volume and bass control pots in their holes and sliding the faceplate over them . Install washers and nuts on the pots to hold the plate in place .
Use the 1MA pot for volume and a 250KA pot for bass . Install them with their lugs facing up for soldering . See the wiring diagram on Page 12 .
Install the backplate the same way, using the two-lug extension speaker jack and the three-lug ground switch .
This switch is just for looks, because ground switches are not needed in modern amps with three-wire grounding power cords . But having it there keeps the vintage 1960s look .
Mount the ground switch so it toggles left/right rather than up/down .
STEP 6
Glue the tube placement chartCut out the tube replacement chart on page 63 . Put a thin coat of glue or contact cement on the back and glue it to the inside wall of the cabinet .
STEP 7
Reverb wiring kitThe shielded wire is in two 3-foot lengths . At the ends of each piece, pull 3/4" of the wire mesh shielding away to one side and strip away 3/8" of the internal cloth shielding . Insert the exposed wire into an RCA plug so that it reaches the tip of the center post .
Solder this lead in place at the tip of the plug . Don’t leave solder on the outside of the plug tip, which would keep it from fitting into the jack . See “Tips for great soldering” on page 11 .
After the plug tip cools and the inside solder joint is set, solder the braided wire shielding onto the outside of the plug . Solder the four RCA plugs this way, on each end of the two cables .
These two cables will connect the reverb tank .
Test for continuity between the tips of the plugs on each cable, then test for continuity between the shields of the plugs in the same way .
Also test to make sure you don’t have continuity between the tip and the shield of each plug, which would indicate a short in the cable . If your multimeter finds unwanted continu-ity, the likely culprit is the inside (tip) wire shorting to the outer shield . If that happens, de-solder the tip con-nection and redo that solder joint .
STEP 4
Install the speakerRemove the nuts from the four speaker-mounting screws . Carefully slide the speaker onto the mounting screws until it’s flush with the front panel .
Install the four speaker-mounting nuts so they’re lightly touching the speaker frame .
Do not tighten the nuts in a circular pattern around the speaker, because this can warp the speaker frame .
Instead tighten one nut with a quarter turn so it’s just snug, then do the same to the opposite side . Then snug the third nut and fourth . Repeat this criss-cross pattern of quarter-turns until all four nuts have had one full turn . This will give proper tension to compress the speaker gasket . Overtightening can warp the frame, damage the cone, and cause unwanted distortion .
Criss-cross tightening prevents warping.
’66 D-Reverb 22WO R I G I N A L A B 7 6 3 C I R C U I T
StewMac®
I C O N K I T S
Use only 1-amp slow-blow fuse, size 5mm x 20mm.
DANGER: Unplug the amp before changing tubes.Tube locations from left to right:
12AX7(ECC83)
12AX7(ECC83)
V5 V4
6V6 12AT7(ECC81)
V7 V6
12AX7(ECC83)
12AX7(ECC83)
V2 V1
12AT7(ECC81)
V3
5AR4(GZ34)
6V6
V9 V8
#10737
stewmac.com 10 © 2019 StewMac
Prepping the eyelet boards
This circuit is built on three eyelet boards: the large main eyelet board, the middle-sized filter cap board, and the small bias board . Gather those three boards now .
STEP 8
Number the eyelets and holesIn these instructions, we’ll refer to the eyelets and holes on the main eyelet board by number . On the bias board and filter cap board, we’ll use letters . Orient the boards as shown below and use a pencil to add the numbers and letters .
L
S
K
RQ
J
P
I
O
H
M
G
N
38
28
1 2 34
56 7 8
51 52
10
34
54
68
58
43
4950
3231
61
4435 36
60
6362
45
36
11
55
41
1214 15
56
42
16
1921
2326
29
46
64
39
4748
30
6566
67
53
9
69 70
71 72
59
5773
7440
13
20 22
27
1817
2524
8385 86 87
90 91 92
94979695
93
98
37
88 89
99
7677
7881
82
79 80
33
84
75A
BC
D
F
E
Main
Bias Filter cap
STEP 10
Drill the filter cap boardsDrill 1/4" holes in the two upper cor-ners of the taped-together filter cap board and insulator (holes G and M) . Drill a third 1/4" hole centered be-tween eyelets P and R (hole Q) .
Separate the boards and set the insu-lator board aside .
The red dots on these boards indicate holes you’ll drill in the next steps . The main board and bias board each get two small mounting holes that don’t need to be numbered .
The filter cap board will get three holes drilled for wires to pass through (holes G, M, and Q) . Even though those holes aren’t there yet, mark the letters as shown while labeling the rest of the holes .
Insulator
Main eyelet board
Filter cap board
Bias boardInsulator
Insulator
Write these numbers + letterson the boards:
M
Q
G
STEP 9
Match the boards + insulatorsFor each of these three boards there is a matching blank insulator board of the same size . These insulators will be mounted behind the eyelet boards to keep the electrical connections from touching the metal chassis .
Align the three insulator boards behind their eyelet boards . Tape the pairs of boards together, to keep them aligned for the next step .
stewmac.com 11 © 2019 StewMac
STEP 11
Drill the bias boardsThe small bias board mounts near the front left corner inside the chassis as indicated by the dotted line in the photo above . Center the taped bias board and insulator over the two mounting holes . Holding the boards in place inside the chassis, use a sharp pencil from the outside to mark the location of the two mounting holes onto the boards . Drill two 3/16" mounting holes, then separate the boards and set the insulator aside .
STEP 12
Drill the main boardsThe main eyelet board needs to be centered between the grommet holes circled in red above .
The right end of the board is 1/2" from the side of the chassis . Position the taped main board and insulator as indicated by the dotted lines .
Mark the mounting holes as you did with the bias boards . Drill two 3/16" mounting holes through these boards and set the insulator aside .
n Don’t think of solder as glue . Good mechanical connections make good electrical connections . Solder’s job is to finalize an already good joint, not to hold the parts on the board . So wrap the leads tightly for good electrical contact before soldering .
n Melt a small amount of solder onto the tip of the iron (“tinning" the iron) . Hold the tip against the joint for a few seconds, until the connection reaches soldering temperature .
Also tin component leads like multi-strand wires to help the solder flow .
Tips for great soldering!n Keep your soldering tip clean by wiping it often on a damp sponge . Keep it tinned by occasionally melting a little solder onto it .
n Feed solder to the connection not to the iron . Keep the iron on the con-nection for a second longer to allow time for all of the flux to cook out of the joint .
n Don’t ever blow on the hot solder or touch anything until the joint is completely cool . A good solder joint is shiny—a sign that it was left to cool undisturbed .
n Trim away the excess wires after the joint has cooled .
n Plan ahead so each joint is only soldered once . Resoldered joints are messy and more likely to fail .
n Position the parts so their specs face out so you can read them later . Many builders also align resistor bands to read in the same direction .
n How much insulation to strip? With plastic insulation, strip 3/8" from the wire ends . Push-back wire works best when you strip away about 1/4" of the cloth wrap .
stew
mac
.com
12
©
2019
Ste
wM
ac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4
OUTPUT TRANSFORMER(Mounted outside)
POW
ER T
RA
NSF
ORM
ER
FILTER CHOKE(Mounted outside)
REVERB DRIVER
(Mounted outside)
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
4 3
21
87
65
4 3
21
87
65
4 3
21
87
65
250KA
1MA
Sold
er
Wra
p
Snip
3 lu
gs e
lect
rical
lyjo
ined
sha
re a
com
mon
gro
und
Snip
stew
mac
.com
13
©
2019
Ste
wM
ac
Inst
alli
ng
th
e ch
assi
s-m
ou
nte
d c
om
po
nen
ts
S
TE
P 1
3
Mo
un
t th
e p
ow
er t
ran
sfo
rmer
+
two
th
ree-
lug
gro
un
din
g s
trip
sTh
e p
ower
tra
nsfo
rmer
has
ten
lea
ds
colo
r-co
ded
in f
our
pairs
, plu
s a
sing
le
red/
yello
w st
riped
lead
and
a si
ngle
red/
blue
str
iped
lead
. Tw
ist
the
sam
e-co
lor
pairs
tog
ethe
r . Fe
ed t
he le
ads
into
the
ch
assi
s th
roug
h th
e sq
uare
hol
e .
Unc
over
the
mou
ntin
g bo
lts a
nd in
stal
l th
e tr
ansf
orm
er o
n th
e ou
tsid
e of
the
ch
assi
s, w
ith f
our
8-32
lock
nuts
insi
de .
Mou
nt t
he t
wo
grou
ndin
g st
rips
at t
he
corn
ers
as s
how
n .
S
TE
P 14
Inst
all s
ix r
ub
ber
gro
mm
ets
Squ
eeze
th
ese
into
th
e si
x h
ole
s as
sh
own .
The
se p
rovi
de st
rain
relie
f for
the
wire
s th
at w
ill p
ass
thro
ugh
the
met
al
chas
sis .
S
TE
P 1
5
Mo
un
t th
e o
utp
ut
tran
sfo
rmer
The
outp
ut t
rans
form
er h
as r
ed, b
lue,
br
own,
bla
ck, a
nd g
reen
lead
s . T
wis
t the
br
own
and
blue
lead
s to
geth
er a
nd th
e gr
een
and
blac
k le
ads
toge
ther
.
Thre
ad th
e gr
een
and
blac
k lea
ds th
roug
h on
e ru
bber
gro
mm
et a
s sh
own .
Thr
ead
the
red,
bro
wn
and
blue
lead
s th
roug
h th
e gr
omm
et to
the
left
as
show
n .
Use
tw
o 8
-32
mac
hin
e sc
rew
s an
d lo
cknu
ts t
o m
ount
the
tra
nsfo
rmer
to
the
outs
ide
of th
e ch
assi
s .
S
TE
P 1
6
Mo
un
t th
e re
verb
dri
ver
The
reve
rb d
river
has
red,
blu
e, g
reen
, and
bl
ack
lead
s . T
hrea
d al
l fou
r lea
ds th
roug
h th
e on
e gr
omm
et a
nd tw
ist t
he g
reen
and
bl
ack
lead
s as
sho
wn .
Use
tw
o 8
-32
mac
hin
e sc
rew
s an
d lo
cknu
ts t
o m
ount
the
rev
erb
driv
er t
o th
e ou
tsid
e of
the
chas
sis .
S
TE
P 1
7
Mo
un
t th
e fi
lter
ch
oke
The
filt
er c
hoke
has
tw
o b
lack
lea
ds .
Thre
ad t
hem
thr
ough
the
gro
mm
eted
ho
le w
ith th
e re
d, b
lue,
and
bro
wn
outp
ut
tran
sfor
mer
lead
s .
Use
tw
o 8
-32
mac
hin
e sc
rew
s an
d lo
cknu
ts to
mou
nt th
e fil
ter c
hoke
out
side
of
the
chas
sis .
S
TE
P 1
8
Inst
all t
he
spea
ker
ou
tpu
t ja
ckA
dd t
he t
hree
-lug
spea
ker
outp
ut ja
ck
next
to
the
two-
lug
exte
nsio
n sp
eake
r ja
ck, w
hich
you
’ve
alre
ady
inst
alle
d .
Thes
e ja
cks
are
elec
tric
ally
gro
unde
d th
roug
h co
ntac
t with
the
met
al c
hass
is,
so ti
ghte
n th
em w
ell f
or a
goo
d gr
ound
.
S
TE
P 19
Inst
all t
he
thre
e la
rge
tub
e so
cket
s w
ith
ten
sio
n c
lip
sO
rient
the
se e
ight
-pin
tub
e so
cket
s so
th
at p
in 1
is c
lose
st t
o th
e re
ar p
anel
of
the
chas
sis .
Use
two
4-40
x 3
/8" m
achi
ne s
crew
s and
lo
cknu
ts to
mou
nt th
ese
sock
ets
on th
e ou
tsid
e of
the
chas
sis .
Incl
ude
a te
nsio
n cl
ip o
n th
e b
otto
m o
f ea
ch s
ocke
t to
pr
ovid
e su
ppor
t for
the
thre
e tu
bes w
hen
they
’re in
stal
led
late
r .
S
TE
P 2
0
Inst
all t
he
six
smal
l tu
be
sock
ets
Use
two
4-40
x 1
/4" m
achi
ne s
crew
s an
d lo
cknu
ts to
mou
nt th
e si
x re
mai
ning
tube
so
cket
s . P
ositi
on th
ese
sock
ets s
o pi
n 3
is
clos
est t
o th
e re
ar p
anel
of t
he c
hass
is .
S
TE
P 2
1
Inst
all t
he
bia
s p
ot
+ o
ne
resi
sto
rM
ount
the
10KL
bia
s pot
in th
e flo
or o
f the
ch
assi
s as s
how
n . W
rap
one
lead
of a
10K
re
sist
or t
hrou
gh t
he le
ft lu
g of
the
bia
s po
t an
d so
lder
it in
to p
lace
. Sol
der
the
othe
r lea
d of
this
resi
stor
to th
e ho
usin
g of
the
bia
s po
t . It
does
n’t
mat
ter
whi
ch
dire
ctio
n th
is re
sist
or is
inst
alle
d, b
ecau
se
resi
stor
s ar
en’t
pola
rized
.
S
TE
P 2
2
Inst
all t
he
fuse
so
cket
Mou
nt t
he f
use
sock
et s
o it
s si
de lu
g fa
ces
the
open
sid
e of
the
cha
ssis
. Thi
s or
ient
atio
n m
akes
it e
asie
r to
sold
er la
ter .
S
TE
P 2
3
Inst
all t
he
po
wer
sw
itch
+
the
stan
db
y sw
itch
Mou
nt th
e po
wer
switc
h an
d th
e st
andb
y sw
itch
with
thei
r lug
s fa
cing
up
for e
asy
sold
erin
g la
ter .
S
TE
P 2
4
Inst
all t
he
fou
r R
CA
jack
sM
ount
th
e RC
A j
acks
to
the
chas
sis
with
the
larg
e w
ashe
rs o
n th
e ou
tsid
e .
Onc
e in
stal
led
, b
end
the
gro
und
ing
tabs
slig
htly
aw
ay fr
om th
e in
side
of t
he
chas
sis .
stew
mac
.com
14
©
2019
Ste
wM
ac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
4 3
21
87
65
4 3
21
87
65
4 3
2
65
4 3
21
87
65
1MA
1MA
250KA
250KA
100KL
3MRA
50KRA
250KA
250KA
47
stew
mac
.com
15
©
2019
Ste
wM
ac
S
TE
P 2
5
Inst
all t
he
pil
ot
lam
p s
ock
etM
ou
nt
the
sock
et b
y sc
rew
ing
th
e le
ns f
rom
the
out
side
into
the
soc
ket
asse
mbl
y . P
ositi
on th
e so
cket
so th
e ar
m
supp
ortin
g th
e la
mp
face
s th
e si
de w
all
of t
he c
hass
is a
nd t
he t
abs
face
up
for
sold
erin
g .
Som
e am
p bu
ilder
s add
a d
rop
of g
lue
to
the
mou
ntin
g th
read
s to
keep
vib
ratio
ns
from
hig
h-vo
lum
e pl
ayin
g fro
m lo
osen
ing
the
sock
et .
S
TE
P 2
6
Inst
all t
he
rem
ain
ing
co
ntr
ol p
ots
Mou
nt th
e co
ntro
l pot
s so
thei
r thr
ee lu
gs
are
faci
ng t
he c
hass
is o
peni
ng . W
hen
we
refe
r to
thes
e lu
gs a
s le
ft o
r rig
ht, i
t’s
assu
min
g yo
u’re
look
ing
at th
e po
t fro
m
the
sam
e p
oint
of
view
as
the
wir
ing
diag
ram
. Mou
nt th
em a
s fo
llow
s:
Vi
brat
o Ch
anne
l Int
ensi
ty: 5
0KRA
pot
Vi
brat
o Ch
anne
l Spe
ed: 3
MRA
pot
Vi
brat
o Ch
anne
l Rev
erb:
100
KL p
ot
Vibr
ato
Chan
nel B
ass:
250K
A p
ot
Vibr
ato
Chan
nel T
rebl
e: 2
50KA
pot
Vi
brat
o Ch
anne
l Vol
ume:
1M
A p
ot
Nor
mal
Cha
nnel
Tre
ble:
250
KA p
ot
S
TE
P 2
7
Inst
all t
wo
res
isto
rsRu
n o
ne
lead
of
a 10
0K r
esis
tor
up
thro
ugh
the
bott
om o
f the
left
lug
of th
e sp
eed
pot a
nd w
rap
it do
wn
thro
ugh
the
mid
dle
lug
of t
he s
ame
pot .
Sold
er t
he
resi
stor
lead
to b
oth
lugs
.
Sold
er t
he o
ther
lead
of
this
res
isto
r to
th
e ba
ck o
f the
spe
ed p
ot .
Wra
p on
e le
ad o
f a 6
.8K
resi
stor
thro
ugh
the
left
lug
of t
he v
ibra
to c
hann
el b
ass
pot a
nd s
olde
r the
lead
to th
is lu
g .
Sold
er t
he 6
.8K
resi
stor
’s ot
her
lead
to
the
back
of t
he v
ibra
to c
hann
el b
ass p
ot .
S
TE
P 2
8
Inst
all o
ne
cap
acit
or
+ o
ne
resi
sto
rRu
n o
ne
lead
of
the
47p
F ca
pac
itor
th
roug
h th
e m
iddl
e lu
g of
the
vib
rato
ch
anne
l vol
ume
pot .
Run
the
othe
r lea
d of
thi
s ca
p th
roug
h th
e rig
ht lu
g of
the
vi
brat
o ch
anne
l vol
ume
pot .
Wra
p th
ese
lead
s aro
und
thes
e lu
gs b
ut d
o no
t sol
der
them
yet
.
Wra
p on
e le
ad o
f a 6
.8K
resi
stor
thro
ugh
the
left
lug
of t
he n
orm
al c
hann
el b
ass
pot a
nd s
olde
r the
lead
to th
is lu
g .
Sold
er t
he 6
.8K
resi
stor
’s ot
her
lead
to
the
back
of t
he n
orm
al c
hann
el b
ass p
ot .
S
TE
P 2
9
Inst
all t
wo
jum
per
sCu
t tw
o 2"
yel
low
jum
pers
.
Wra
p on
e en
d of
the
first
jum
per t
hrou
gh
the
mid
dle
lug
of t
he v
ibra
to c
hann
el
bass
pot
and
wra
p th
e ot
her e
nd o
f thi
s ju
mpe
r thr
ough
the
left
lug
of th
e vi
brat
o ch
anne
l tre
ble
pot .
Sold
er th
is le
ad in
to
the
left
lug
of th
e tr
eble
pot
but
not
the
mid
dle
lug
of th
e ba
ss p
ot .
Wra
p o
ne
end
of
the
oth
er j
um
per
th
roug
h th
e m
iddl
e lu
g of
the
vib
rato
ch
anne
l tre
ble
pot a
nd th
e ot
her e
nd o
f th
e sa
me
jum
per t
hrou
gh th
e rig
ht lu
g of
th
e vi
brat
o ch
anne
l vol
ume
pot .
Sold
er
this
lead
into
bot
h lu
gs .
S
TE
P 3
0
Inst
all t
wo
mo
re ju
mp
ers
Cut t
wo
mor
e 2"
yel
low
jum
pers
.
Wra
p on
e en
d of
the
first
jum
per t
hrou
gh
the
mid
dle
lug
of t
he n
orm
al c
hann
el
bass
pot
and
wra
p th
e ot
her e
nd o
f thi
s ju
mpe
r thr
ough
the
left
lug
of th
e no
rmal
ch
anne
l tre
ble
pot .
Sold
er th
is le
ad in
to
the
left
lug
of th
e tr
eble
pot
but
not
the
mid
dle
lug
of th
e ba
ss p
ot .
Wra
p o
ne
end
of
the
oth
er j
um
per
th
roug
h th
e m
iddl
e lu
g of
the
nor
mal
ch
anne
l tre
ble
pot a
nd th
e ot
her e
nd o
f th
e sa
me
jum
per t
hrou
gh th
e rig
ht lu
g of
th
e no
rmal
cha
nnel
vol
ume
pot .
Sold
er
this
lead
into
bot
h lu
gs .
S
TE
P 3
1
Inst
all v
ibra
to c
han
nel
jack
s +
1M
res
isto
rA
dd v
ibra
to c
hann
el in
stru
men
t ja
cks
1 an
d 2 .
Pos
ition
them
so th
e ce
nter
lug
of
jack
2 is
clo
se to
the
left
lug
of ja
ck 1
as
pict
ured
.
Wra
p on
e le
ad o
f a 1
M r
esis
tor
thro
ugh
the
right
lug
of ja
ck 1
and
wra
p it
onto
th
e ce
nter
lug
of th
e sa
me
jack
. Mak
e su
re
the
lead
or t
he b
ody
of th
e re
sist
or w
on’t
be in
the
way
whe
n an
inst
rum
ent c
able
is
plu
gged
in .
Run
this
resi
stor
’s ot
her l
ead
thro
ugh
the
left
lug
of ja
ck 1
and
ont
o th
e ce
nter
lug
of
jack
2 . D
on’t
sold
er th
ese
conn
ectio
ns ye
t .
For ne
at loo
king w
iring,
use wi
re str
ippers
to
trim 1/
4" of t
he ins
ulation
fro
m the
ends o
f the
push-b
ack wi
re.
stew
mac
.com
16
©
2019
Ste
wM
ac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4
POW
ER T
RA
NSF
ORM
ER
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
4 3
21
87
65
4 3
21
87
65
4 3
2
65
4 3
21
87
65
stew
mac
.com
17
©
2019
Ste
wM
ac
S
TE
P 3
2
Inst
all t
wo
68
K r
esis
tors
on
th
e vi
bra
to c
han
nel
jack
sTw
ist
the
lead
s of
tw
o 68
K re
sist
ors
toge
ther
, cre
atin
g on
e co
nnec
tion .
Wra
p th
e ot
her l
ead
from
one
resi
stor
ont
o th
e rig
ht lu
g of
vib
rato
jack
2 a
s sh
own .
Wra
p th
e re
mai
ning
resi
stor
lead
ont
o th
e le
ft lu
g of
vib
rato
jack
1, a
ddin
g it
to th
e co
nnec
tion
mad
e in
the
prev
ious
ste
p .
Sold
er a
ll th
ese
conn
ectio
ns, a
nd a
lso
sold
er th
e tw
iste
d 68
K re
sist
or le
ads .
S
TE
P 3
3
Inst
all n
orm
al c
han
nel
jack
s +
1M
res
isto
rA
dd n
orm
al c
hann
el in
stru
men
t ja
cks
1 an
d 2 .
Pos
ition
them
so th
e ce
nter
lug
of
jack
2 is
clo
se to
the
left
lug
of ja
ck 1
as
pict
ured
.
Wra
p on
e le
ad o
f a 1
M r
esis
tor
thro
ugh
the
right
lug
of ja
ck 1
and
wra
p it
onto
th
e ce
nter
lug
of th
e sa
me
jack
. Mak
e su
re
the
lead
or t
he b
ody
of th
e re
sist
or w
on’t
be in
the
way
whe
n an
inst
rum
ent c
able
is
plu
gged
in .
Run
this
resi
stor
’s ot
her l
ead
thro
ugh
the
left
lug
of ja
ck 1
and
ont
o th
e ce
nter
lug
of
jack
2 . D
on’t
sold
er th
ese
conn
ectio
ns ye
t .
S
TE
P 3
4
Inst
all t
wo
68
K r
esis
tors
on
th
e n
orm
al c
han
nel
jack
sTw
ist
the
lead
s of
tw
o 68
K re
sist
ors
toge
ther
, cre
atin
g on
e co
nnec
tion .
Wra
p th
e ot
her l
ead
from
one
resi
stor
ont
o th
e rig
ht lu
g of
jack
2 a
s sh
own .
Wra
p th
e re
mai
ning
res
isto
r le
ad o
nto
the
left
lug
of ja
ck 1
, add
ing
it t
o th
e co
nnec
tion
mad
e in
the
prev
ious
ste
p .
Sold
er a
ll th
ese
conn
ectio
ns, a
nd a
lso
sold
er th
e tw
iste
d 68
K re
sist
or le
ads .
S
TE
P 3
5
Po
wer
tra
nsf
orm
er b
lack
lead
sRu
n ei
ther
of
the
blac
k w
ires
from
the
po
wer
tran
sfor
mer
to th
e si
de lu
g of
the
fuse
sock
et . T
rim it
to fi
t and
sold
er it
. Trim
an
d so
lder
the
othe
r bla
ck w
ire to
the
left
lu
g on
the
pow
er s
witc
h .
S
TE
P 3
6
Po
wer
tra
nsf
orm
er g
reen
lead
sRu
n th
e tw
o gr
een
wire
s fro
m th
e po
wer
tr
ansf
orm
er to
the
lugs
on
the
pilo
t lam
p so
cket
(eith
er w
ire c
an g
o to
eith
er lu
g) .
Trim
the
se w
ires
to
leng
th a
nd w
rap
them
ont
o th
e lu
gs . D
on’t
sold
er t
hese
co
nnec
tions
yet
.
S
TE
P 3
7
Po
wer
tra
nsf
orm
er r
ed/y
ello
w le
adTr
im th
e po
wer
tran
sfor
mer
’s re
d/ye
llow
le
ad to
an
appr
opria
te le
ngth
and
sold
er
it to
the
grou
ndin
g st
rip a
s sh
own .
S
TE
P 3
8
Po
wer
tra
nsf
orm
er r
ed le
ads
Trim
the
pow
er t
rans
form
er’s
red
lead
s to
an
appr
opria
te le
ngth
and
wra
p on
e le
ad o
nto
pin
4 of
soc
ket V
9 . T
he p
ins o
n th
e 8-
pin
sock
ets
have
upp
er a
nd lo
wer
ey
elet
s fo
r mul
tiple
con
nect
ions
.
Wra
p th
e ot
her
red
lead
ont
o pi
n 6
of
the
sam
e so
cket
. Don
’t so
lder
thes
e re
d le
ads
yet .
S
TE
P 3
9
Po
wer
tra
nsf
orm
er y
ello
w le
ads
Trim
the
pow
er tr
ansf
orm
er’s
yello
w le
ads
to a
n ap
prop
riate
leng
th . W
rap
one
of
thes
e le
ads
onto
pin
2 o
f soc
ket V
9 .
Wra
p th
e ot
her
yello
w le
ad o
nto
pin
8 of
the
sam
e so
cket
. Don
’t so
lder
the
se
yello
w le
ads
yet .
stew
mac
.com
18
©
2019
Ste
wM
ac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
4 3
21
87
65
4 3
21
87
65
6
4321
98 7 5
4 3
21
87
65
V3
12A
T7
6
4321
98 7 5
stew
mac
.com
19
©
2019
Ste
wM
ac
S
TE
P 4
0
Ou
tpu
t tr
ansf
orm
er
blu
e +
bro
wn
lead
sTr
im t
he
blu
e w
ire
from
th
e ou
tput
tr
ansf
orm
er t
o an
app
ropr
iate
len
gth
and
wra
p it
onto
pin
3 o
f soc
ket V
7 . D
on’t
sold
er th
is c
onne
ctio
n ye
t .
Trim
the
bro
wn
wire
fro
m t
he o
utpu
t tr
ansf
orm
er t
o an
app
ropr
iate
len
gth
and
wra
p it
onto
pin
3 o
f soc
ket V
8 . D
on’t
sold
er th
is c
onne
ctio
n ye
t .
Leav
e th
e re
d ou
tput
tra
nsfo
rmer
lead
fr
ee fo
r now
; you
'll c
onne
ct it
late
r, w
hen
the
eyel
et b
oard
is in
stal
led .
S
TE
P 4
1
Ad
d t
wo
jum
per
sA
dd a
1-1
/2" y
ello
w ju
mpe
r bet
wee
n th
e rig
ht lu
g of
the
spea
ker j
ack
and
the
right
lu
g of
the
ext
ensi
on ja
ck . W
rap
thes
e jo
ints
, but
do
not s
olde
r the
m y
et .
Cut a
3/4
" yel
low
jum
per a
nd re
mov
e th
e in
sula
tion .
Add
thi
s sh
ort
wire
bet
wee
n th
e sp
eake
r jac
k’s l
eft l
ug a
nd c
ente
r lug
. So
lder
the
both
end
s .
S
TE
P 4
2
Ou
tpu
t tr
ansf
orm
er
gre
en +
bla
ck le
ads
Trim
thes
e tw
o w
ires t
o re
ach
the
spea
ker
jack
and
ext
ensi
on s
peak
er ja
ck .
Sold
er th
e gr
een
lead
to th
e rig
ht lu
g of
th
e sp
eake
r ja
ck a
long
with
the
jum
per
from
the
prev
ious
ste
p .
Sold
er th
e bl
ack
lead
to th
e le
ft lu
g of
the
exte
nsio
n sp
eake
r jac
k .
S
TE
P 4
3
Co
nn
ect
the
reve
rb d
rive
r le
ads
Trim
the
gree
n le
ad to
reac
h th
e m
iddl
e lu
g of
the
rev
erb
inpu
t ja
ck, t
in it
and
so
lder
it to
the
lug .
Trim
the
blac
k le
ad to
reac
h th
e gr
ound
tab
on th
e re
verb
inpu
t ja
ck . T
in it
and
sol
der
it to
thi
s ta
b .
Trim
the
blue
lead
to re
ach
pin
6 of
sock
et
V3 . T
in it
and
wra
p it
onto
the
pin
, but
do
n’t s
olde
r it y
et .
Leav
e th
e re
d le
ad fr
ee fo
r now
; you
will
in
stal
l it t
o th
e ey
elet
boa
rd la
ter o
n .
S
TE
P 4
4
Ad
d t
hre
e ye
llo
w ju
mp
ers
Cut t
wo
1" y
ello
w ju
mpe
rs . W
rap
one
of
them
bet
wee
n pi
n 2
and
pin
7 of
soc
ket
V3 . S
olde
r the
con
nect
ion
to p
in 2
.
Wra
p th
e se
cond
shor
t jum
per b
etw
een
pin
3 an
d pi
n 8
of s
ocke
t V3 .
Sol
der t
he
conn
ectio
n to
pin
3 .
Cut a
2-1
/2" y
ello
w ju
mpe
r and
conn
ect i
t be
twee
n pi
ns 1
and
6 o
n so
cket
V3 .
Rou
te
this
jum
per
in a
sem
icirc
le a
roun
d th
e ba
ck o
f the
soc
ket .
Sold
er th
is ju
mpe
r at
pin
1 an
d al
so a
t pin
6 w
here
it jo
ins
the
blue
wire
from
the
reve
rb d
river
.
S
TE
P 4
5
Ad
d t
hre
e m
ore
yel
low
jum
per
sCu
t one
2-1
/2" y
ello
w ju
mpe
r . W
rap
one
end
of th
is ju
mpe
r in
pin
8 of
soc
ket V
1 .
Wra
p th
e ot
her e
nd o
f thi
s jum
per i
n pi
n 8
of s
ocke
t V2 .
Sol
der t
he c
onne
ctio
n at
pi
n 8
of V
1 .
Cut t
wo
1" y
ello
w ju
mpe
rs . W
rap
one
of
them
bet
wee
n pi
n 3
and
pin
8 of
soc
ket
V4 . S
olde
r the
con
nect
ion
at p
in 3
.
Wra
p th
e se
cond
sho
rt ju
mpe
r bet
wee
n pi
n 3
and
pin
8 of
soc
ket V
6 . S
olde
r the
co
nnec
tion
at p
in 3
.
Gro
und
tab
stew
mac
.com
2
0
©20
19 S
tew
Mac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
4 3
21
87
65
6
4321
98 7 5
4 3
21
87
65
4 3
21
87
65
stew
mac
.com
2
1
©20
19 S
tew
Mac
S
TE
P 4
6
Ad
d t
wo
jum
per
s +
on
e re
sist
or
Cut o
ne 1
-1/4
” ye
llow
jum
per .
Wra
p on
e en
d th
roug
h th
e m
iddl
e lu
g of
the
reve
rb
outp
ut R
CA ja
ck a
nd w
rap
the
othe
r end
th
roug
h th
e m
iddl
e lu
g of
the
rev
erb
peda
l RCA
jack
. Sol
der t
his j
umpe
r to
the
reve
rb o
utpu
t RCA
jack
.
Add
a 2
20K
resi
stor
bet
wee
n th
e m
iddl
e lu
g of
the
reve
rb p
edal
RCA
jack
and
the
grou
nd lu
g of
the
vibr
ato
peda
l RCA
jack
. So
lder
it in
to th
e gr
ound
lug
of th
e re
verb
ou
tput
RCA
jack
.
Cut
a 3-
1/2”
yel
low
jum
per .
Wra
p on
e en
d th
roug
h th
e m
iddl
e lu
g of
the
reve
rb
outp
ut R
CA ja
ck a
nd w
rap
the
othe
r end
th
roug
h pi
n 2
of s
ocke
t V4
. Sol
der
this
ju
mpe
r at b
oth
ends
.
S
TE
P 4
7
Ad
d fo
ur
resi
sto
rsA
dd o
ne 1
.5K
resi
stor
bet
wee
n pi
n 1
and
pin
5 of
soc
ket
V7 . S
olde
r bo
th le
ads
in
to p
lace
.
Add
one
1 .5
K re
sist
or b
etw
een
pin
1 an
d pi
n 5
of s
ocke
t V8
. Sol
der
both
lead
s in
to
pla
ce .
Add
one
470
Ω 1
W re
sist
or b
etw
een
pin
4 an
d pi
n 6
of so
cket
V7 .
Sta
nd th
is re
sist
or
up o
ff t
he s
ocke
t ab
out
half
an i
nch .
So
lder
the
lead
wra
pped
in p
in 4
.
Add
one
470
Ω 1
W re
sist
or b
etw
een
pin
4 an
d pi
n 6
of so
cket
V8 .
Sta
nd th
is re
sist
or
up o
ff t
he s
ocke
t ab
out
half
an i
nch .
So
lder
the
lead
wra
pped
in p
in 4
.
S
TE
P 4
8
Ad
d t
hre
e ju
mp
ers
Cut
one
3-1/
2" y
ello
w j
ump
er . S
olde
r on
e en
d to
pin
6 o
f soc
ket V
8 . W
rap
one
end
onto
pin
6 o
f soc
ket
V7, b
ut d
o no
t so
lder
it y
et .
Cut o
ne 3
-1/2
" gre
en ju
mpe
r . So
lder
one
en
d to
pin
8 o
f soc
ket V
7 . W
rap
the
othe
r en
d on
to p
in 8
of s
ocke
t V8,
but
do
not
sold
er it
yet
.
Cut o
ne 3
" gre
en ju
mpe
r . W
rap
one
end
in p
in 8
of s
ocke
t V8 .
Wra
p th
e ot
her e
nd
thro
ugh
one
of th
e lu
gs o
f the
thre
e-lu
g gr
ound
ing
stri
p cl
oses
t to
soc
ket
V8 .
Sold
er b
oth
ends
of t
his
jum
per .
Sto
p a
nd
insp
ect
you
r w
ork
This
is a
goo
d tim
e to
step
aw
ay fr
om th
e pr
ojec
t fo
r a
few
min
utes
. Tak
e a
brea
k be
fore
revi
ewin
g yo
ur w
ork
for e
rror
s .
Whe
n yo
u’re
read
y to
go
at it
aga
in, v
ery
care
fully
wal
k th
roug
h ev
ery
conn
ectio
n yo
u’ve
mad
e so
far
. Whe
n ev
eryt
hing
ch
ecks
out
, you
’re r
eady
to
mov
e on
to
the
eyel
et b
oard
.
STOP
Be sus
piciou
s The
re's a
mistak
e, and
you’re
gonna
find it!
stew
mac
.com
2
2
©20
19 S
tew
Mac
AB
CD
FE
+
25µ
F
How
to
inst
all p
arts
on
an
eye
let
bo
ard
in t
hre
e st
eps
Wra
p
Don
’t so
lder
the
com
pone
nts
as t
hey
go
onto
th
e ey
elet
b
oard
. Ins
tead
wra
p a
ll th
e pa
rts o
nto
the
boar
d, b
endi
ng
thei
r lea
ds ti
ghtly
so
the
part
s st
ay in
pla
ce w
ithou
t sol
der .
Insp
ect
Whe
n al
l the
par
ts a
re in
pla
ce,
stop
and
insp
ect .
Go
back
ove
r ev
ery
step
. Car
eful
insp
ectio
n is
the
bes
t w
ay t
o m
ake
sure
yo
ur a
mp
wor
ks th
e fir
st ti
me
you
turn
it o
n .
Sold
erSo
lder
eac
h co
nnec
tion
poin
t on
ly o
nce .
Reh
eatin
g to
add
an
othe
r pa
rt m
akes
a m
essy
, fa
ulty
sol
der
joi
nt .
Use
the
so
lder
ing
tips
on p
age
11 t
o ge
t pro
fess
iona
l res
ults
.
stew
mac
.com
2
3
©20
19 S
tew
Mac
Wra
pp
ing
par
ts o
nto
th
e b
ias
bo
ard
The
bias
boa
rd i
s th
e sm
alle
st o
f th
e th
ree
eyel
et b
oard
s . P
ositi
on it
as s
how
n ab
ove,
with
hol
e D
to
the
uppe
r rig
ht,
and
the
pair
of m
ount
ing
hole
s to
war
d th
e bo
ttom
.
S
TE
P 4
9
Ad
d o
ne
resi
sto
rA
dd a
470
Ω 1
W re
sist
or b
etw
een
eyel
ets
A a
nd B
.
Don
’t so
lder
the
se c
onne
ctio
ns . Y
ou’ll
so
lder
the
con
nect
ions
on
both
eye
let
boa
rds
late
r, af
ter
all
thei
r p
arts
are
w
rapp
ed in
pla
ce a
nd d
oubl
e-ch
ecke
d .
S
TE
P 5
0
Ad
d a
cap
acit
or
and
a d
iod
eAd
d a 2
5μF e
lect
roly
tic ca
paci
tor b
etw
een
eyel
ets E
and
F . N
ote
the
po
lari
ty o
f th
e ca
pac
ito
r. C
onne
ct t
he c
ap’s
nega
tive
lead
to e
yele
t F .
Add
the
rect
ifier
dio
de b
etw
een
eyel
ets B
an
d C .
Not
e th
e po
larit
y . T
he p
ositi
ve le
ad
of th
e di
ode
is in
dica
ted
by a
strip
e at
that
en
d . T
he e
nd w
ith n
o st
ripe
is n
egat
ive .
Co
nnec
t the
neg
ativ
e le
ad to
eye
let C
.
S
TE
P 5
1
Ad
d t
wo
jum
per
sCu
t a 1
-1/8
" ye
llow
jum
per .
Flip
the
bias
bo
ard
over
and
add
this
jum
per b
etw
een
eyel
ets C
and
F o
n th
e ba
ck o
f the
boa
rd .
Cut
a 4"
yel
low
jum
per .
Wra
p on
e en
d th
roug
h ey
elet
C a
nd ru
n th
e re
st d
own
thro
ugh
hole
D . P
ull i
t tig
ht to
kee
p it
in
plac
e .
S
TE
P 5
2
Ad
d o
ne
jum
per
Cut
one
7" g
reen
jum
per
and
wra
p on
e en
d th
roug
h ey
elet
E .
Set
the
bia
s b
oar
d a
sid
eSt
ore
the
bias
boa
rd s
omew
here
tha
t it
won
’t be
dis
turb
ed . Y
ou’re
rea
dy t
o tu
rn y
our
atte
ntio
n to
the
filt
er c
ap
eyel
et b
oard
.
stew
mac
.com
24
©
2019
Ste
wM
ac
G
NH
OI
PJ
RK
SLM
Q
16μF
16μF
16μF
16μF
16μF
stew
mac
.com
2
5
©20
19 S
tew
Mac
The
filte
r cap
boa
rd is
the
med
ium
-siz
ed
of th
e th
ree
eyel
et b
oard
s . P
ositi
on it
as
show
n ab
ove,
with
the
thro
ugh
hole
s in
th
e to
p tw
o co
rner
s .
S
TE
P 5
3
Ad
d fi
ve c
apac
ito
rsAd
d a 1
6μF
elec
trol
ytic
capa
cito
r bet
wee
n ey
elet
s H
and
N . N
ote
the
pola
rity
of th
e ca
paci
tor .
Conn
ect
the
cap’
s ne
gati
ve
lead
to e
yele
t N .
Add
ano
ther
16μ
F el
ectr
olyt
ic c
apac
itor
betw
een
eyel
ets I
and
O . N
ote
the
pola
rity
of
the
cap
acit
or .
Co
nn
ect
the
cap
’s
nega
tive
lead
to e
yele
t O .
Add
a t
hird
16μ
F el
ectr
olyt
ic c
apac
itor
betw
een
eyel
ets J
and
P . N
ote
the
pola
rity
of
the
cap
acit
or .
Co
nn
ect
the
cap
’s
nega
tive
lead
to e
yele
t P .
Add
a fo
urth
16μ
F el
ectr
olyt
ic c
apac
itor
bet
wee
n e
yele
ts K
an
d R
. N
ote
th
e po
larit
y of
the
cap
acito
r . Co
nnec
t th
e ca
p’s
nega
tive
lead
to e
yele
t R .
Add
a fi
fth
16μF
ele
ctro
lytic
cap
acito
r be
twee
n ey
elet
s L a
nd S
. Not
e th
e po
larit
y o
f th
e ca
pac
ito
r . C
on
nec
t th
e ca
p’s
ne
gativ
e le
ad to
eye
let S
.
S
TE
P 5
4
Ad
d fo
ur
jum
per
sCu
t fou
r 1-1
/2" g
reen
jum
pers
.
Wra
p th
e fir
st b
etw
een
eyel
ets
N a
nd O
.
Wra
p t
he s
econ
d b
etw
een
eyel
ets
O
and
P .
Wra
p th
e th
ird b
etw
een
eyel
ets
R an
d S .
Wra
p th
e fo
urth
bet
wee
n ey
elet
s K a
nd L
.
S
TE
P 5
5
Ad
d t
wo
res
isto
rsA
dd a
10K
2W
res
isto
r be
twee
n ey
elet
s H
and
I .
Add
ano
ther
10K
2W
res
isto
r be
twee
n ey
elet
s I a
nd J .
S
TE
P 5
6
Ad
d fo
ur
jum
per
sCu
t tw
o 6"
gre
en ju
mpe
rs .
Wra
p on
e en
d of
one
thr
ough
eye
let
S .
Pull
the
othe
r en
d th
roug
h ho
le M
and
pu
ll it
tight
to k
eep
it in
pla
ce .
Wra
p o
ne
end
of
the
oth
er j
um
per
th
roug
h ey
elet
N . P
ull
the
othe
r en
d th
roug
h ho
le G
and
pul
l it t
ight
to k
eep
it in
pla
ce .
Cut t
wo
6" y
ello
w ju
mpe
rs a
nd tw
ist t
hem
to
geth
er ti
ght .
Wra
p on
e en
d of
eac
h ju
mpe
r th
roug
h ey
elet
J .
Then
run
the
tw
iste
d l
eads
th
roug
h ho
le Q
and
pul
l the
m t
ight
to
keep
them
in p
lace
.
S
TE
P 5
7
Ad
d fo
ur
jum
per
sCu
t a
6" y
ello
w ju
mpe
r an
d w
rap
one
end
thro
ugh
eyel
et L
. Pul
l the
oth
er e
nd
thro
ugh
hole
M a
nd p
ull i
t tig
ht to
kee
p it
in p
lace
.
Cut
a 7"
yel
low
jum
per
and
wra
p on
e en
d th
roug
h ey
elet
J . P
ull t
he o
ther
end
th
roug
h ho
le M
and
pul
l it t
ight
to k
eep
it in
pla
ce .
Cut
an 8
" ye
llow
jum
per
and
wra
p on
e en
d th
roug
h ey
elet
I . P
ull t
he o
ther
end
th
roug
h ho
le M
and
pul
l it t
ight
to k
eep
it in
pla
ce .
Cut
a 3"
yel
low
jum
per
and
wra
p on
e en
d th
roug
h ey
elet
H . P
ull t
he o
ther
end
th
roug
h ho
le G
and
pul
l it t
ight
to k
eep
it in
pla
ce .
Set
the
filt
er c
ap b
oar
d a
sid
eSt
ore
the
filte
r cap
boa
rd so
mew
here
that
it
won
’t be
dis
turb
ed . Y
ou’re
read
y to
turn
yo
ur a
tten
tion
to th
e m
ain
eyel
et b
oard
.
Wra
pp
ing
par
ts o
nto
th
e fi
lter
cap
bo
ard
stew
mac
.com
2
6
©20
19 S
tew
Mac
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
104J 600V
104J 600V
473J 600V
250
473J 600V
+25µF
+25µF
stew
mac
.com
27
©
2019
Ste
wM
ac
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
104J 600V
104J 600V
473J 600V
250
473J 600V
+25µF
+25µF
The
mai
n ey
elet
boa
rd is
the
larg
est o
f the
th
ree
eyel
et b
oard
s . P
ositi
on it
as s
how
n ab
ove,
with
hol
e 27
in th
e to
p rig
ht a
nd
hole
75
in th
e bo
ttom
left
.
S
TE
P 5
8
Inst
all a
.1μ
F ca
p +
on
e ju
mp
erW
rap
a .1
μF O
rang
e D
rop
cap
betw
een
eyel
ets 2
6 an
d 99
. Thi
s cap
acito
r doe
s not
ha
ve p
olar
ity a
nd c
an b
e in
stal
led
faci
ng
eith
er d
irect
ion .
Cut a
7-1
/2" y
ello
w ju
mpe
r . Tu
rn th
e bo
ard
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 26 .
Run
the
othe
r end
of
this
jum
per u
p th
roug
h ho
le 2
5 an
d pu
ll it
tight
so
it st
ays
in p
lace
.
S
TE
P 5
9
Inst
all a
.047
μF
cap
+ o
ne
jum
per
Add
a .0
47μF
Ora
nge
Dro
p ca
pac
itor
be
twee
n ey
elet
s 37
and
99 .
Thi
s ca
p is
no
t pol
ariz
ed a
nd c
an b
e in
stal
led
faci
ng
eith
er d
irect
ion .
Cut
a 7"
yel
low
jum
per .
Turn
the
boa
rd
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 37 .
Run
the
othe
r end
of
this
jum
per u
p th
roug
h ho
le 2
4 an
d pu
ll it
tight
so
it st
ays
in p
lace
.
S
TE
P 6
0
Inst
all a
10
0K
res
isto
r +
on
e ju
mp
er
Add
a 1
00K
resi
stor
bet
wee
n ey
elet
s 98
an
d 99
.
Cut a
1-1
/4" y
ello
w ju
mpe
r, fli
p th
e bo
ard
over
, and
add
the
jum
per
behi
nd t
he
boar
d be
twee
n ey
elet
s 63
and
98 .
S
TE
P 6
1
Inst
all a
250
pF
cap
+ o
ne
jum
per
Add
a 2
50pF
silv
er m
ica
cap
betw
een
eyel
ets
45 a
nd 6
3 .
Cut
a 6-
3/4"
yel
low
jum
per
. Tur
n th
e bo
ard
over
and
wra
p th
is ju
mpe
r thr
ough
th
e bo
ttom
of
eyel
et 4
5 . R
un t
he o
ther
en
d of
thi
s ju
mpe
r up
thr
ough
hol
e 24
an
d pu
ll it
tight
so
it st
ays
in p
lace
.
S
TE
P 6
2
Inst
all t
wo
10
0K
res
isto
rsA
dd a
100
K re
sist
or b
etw
een
eyel
ets
62
and
98 .
Ad
d a
not
her
100
K re
sist
or b
etw
een
eyel
ets
62 a
nd 9
7 .
S
TE
P 6
3
Inst
all a
.047
μF
cap
Add
a .0
47μF
Ora
nge
Dro
p ca
p be
twee
n ey
elet
s 23
and
97 .
S
TE
P 6
4
Ad
d t
wo
jum
per
sCu
t a 2
" jum
per a
nd a
dd it
to e
yele
t 97 .
Cut a
2-3
/4" j
umpe
r and
add
it to
eye
let
98 .
Cut
a 10
-1/2
" ye
llow
jum
per .
Turn
the
bo
ard
over
and
wra
p th
is ju
mpe
r thr
ough
th
e bo
ttom
of
eyel
et 2
3 . R
un t
he o
ther
en
d of
thi
s ju
mpe
r up
thr
ough
hol
e 22
an
d pu
ll it
tight
so
it st
ays
in p
lace
.
S
TE
P 6
5
Inst
all a
25
μF
cap
+ a
1.5
K r
esis
tor,
so
lder
ed t
og
eth
erW
rap
the
lead
s fr
om t
he 1
.5K
resi
stor
ar
ou
nd
th
e le
ads
on
th
e 25
μF
50V
capa
cito
r and
sold
er th
em to
geth
er . N
ote
the
pola
rity
of th
e ca
paci
tor .
Inst
all t
his
resi
stor
/cap
acito
r as
sem
bly
betw
een
eyel
ets
21 a
nd 9
6, m
akin
g su
re
the
capa
cito
r’s n
egat
ive
lead
goe
s to
ey
elet
21 .
S
TE
P 6
6
Inst
all a
no
ther
25
μF
cap
+ a
1.5
K
resi
sto
r, s
old
ered
to
get
her
Wra
p th
e le
ads
from
the
1 .5
K re
sist
or
aro
un
d t
he
lead
s o
n t
he
25μ
F 50
V ca
paci
tor a
nd so
lder
them
toge
ther
. Not
e th
e po
larit
y of
the
capa
cito
r .
Inst
all t
his
resi
stor
/cap
acito
r as
sem
bly
betw
een
eyel
ets
21 a
nd 9
5, m
akin
g su
re
the
capa
cito
r’s n
egat
ive
lead
goe
s to
ey
elet
21 .
S
TE
P 6
7
Ad
d t
wo
jum
per
sCu
t a 3
-1/2
" yel
low
jum
per a
nd w
rap
one
end
thro
ugh
eyel
et 9
6 .
Cut
one
3-1/
4" y
ello
w ju
mpe
r an
d w
rap
one
end
thro
ugh
eyel
et 9
5 .
S
TE
P 6
8
Ad
d a
.1μ
F ca
p +
on
e ju
mp
erA
dd a
.1μF
Ora
nge
Dro
p ca
p be
twee
n ey
elet
s 19
and
94 .
Cut
a 10
-3/4
" ye
llow
jum
per .
Turn
the
bo
ard
over
and
wra
p th
is ju
mpe
r thr
ough
th
e bo
ttom
of
eyel
et 1
9 . R
un t
he o
ther
en
d of
thi
s ju
mpe
r up
thr
ough
hol
e 18
an
d pu
ll it
tight
so
it st
ays
in p
lace
.
Wra
pp
ing
par
ts o
nto
th
e m
ain
eye
let
bo
ard
96
21
+
25μ
F
Posi
tive
Neg
ativ
e
21
95
+
25μ
F
Posi
tive
Neg
ativ
e
stew
mac
.com
2
8
©20
19 S
tew
Mac
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
473J 600V
250
223J 600V
332J 600V
+25µF
510+
+25µF
104J 600V
stew
mac
.com
29
©
2019
Ste
wM
ac
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
473J 600V
250
223J 600V
332J 600V
+25µF
510+
+25µF
104J 600V
S
TE
P 6
9
Inst
all a
.047
μF
cap
+ o
ne
jum
per
Add
a .0
47μF
Ora
nge
Dro
p ca
pac
itor
be
twee
n ey
elet
s 36
and
94 .
Cut
an 1
1-1/
2" y
ello
w ju
mpe
r . Tu
rn t
he
boar
d ov
er a
nd w
rap
this
jum
per t
hrou
gh
the
bott
om o
f ey
elet
36 .
Run
the
oth
er
end
of t
his
jum
per
up t
hrou
gh h
ole
17
and
pull
it tig
ht s
o it
stay
s in
pla
ce .
S
TE
P 7
0
Inst
all a
10
0K
res
isto
r +
on
e ju
mp
erA
dd a
100
K re
sist
or b
etw
een
eyel
ets
93
and
94 .
Cut a
1-1
/4" y
ello
w ju
mpe
r, fli
p th
e bo
ard
over
and
add
the
jum
per
beh
ind
the
boar
d be
twee
n ey
elet
s 61
and
93 .
S
TE
P 7
1
Inst
all a
250
pF
cap
+ o
ne
jum
per
Add
a 2
50pF
cap
bet
wee
n ey
elet
s 44
an
d 61
.
Cut a
9-1
/2" y
ello
w ju
mpe
r . Tu
rn th
e bo
ard
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 44 .
Run
the
othe
r end
of
this
jum
per u
p th
roug
h ho
le 1
8 an
d pu
ll it
tight
so
it st
ays
in p
lace
.
S
TE
P 7
2
Inst
all t
wo
10
0K
res
isto
rsA
dd a
100
K re
sist
or b
etw
een
eyel
ets
60
and
93 .
Ad
d a
not
her
100
K re
sist
or b
etw
een
eyel
ets
60 a
nd 9
2 .
S
TE
P 7
3
Inst
all o
ne
jum
per
Cut a
1-1
/2" y
ello
w ju
mpe
r, fli
p th
e bo
ard
over
and
add
the
jum
per
beh
ind
the
boar
d be
twee
n ey
elet
s 35
and
60 .
S
TE
P 7
4
Inst
all t
wo
10
0K
res
isto
rsA
dd a
.022
μF O
rang
e D
rop
cap
betw
een
eyel
ets
92 a
nd 5
8 .
Add
a 5
" yel
low
jum
per t
o ey
elet
93 .
Add
a 3
-1/2
" yel
low
jum
per t
o ey
elet
92 .
S
TE
P 7
5
Inst
all a
50
0p
F ca
p +
1M
res
isto
rA
dd a
500
pF s
ilver
mic
a ca
p be
twee
n ey
elet
s 43
and
58 .
Add
a 1
M r
esis
tor
betw
een
eyel
ets
16
and
43 .
S
TE
P 7
6
Inst
all a
25
μF
cap
+ a
n 8
20Ω
re
sist
or,
so
lder
ed t
og
eth
erW
rap
the
lead
s fr
om t
he 8
20Ω
res
isto
r ar
ou
nd
th
e le
ads
on
th
e 25
μF
50V
capa
cito
r and
sold
er th
em to
geth
er . N
ote
the
pola
rity
of th
e ca
paci
tor .
Inst
all t
his
resi
stor
/cap
acito
r as
sem
bly
betw
een
eyel
ets
16 a
nd 9
1, m
akin
g su
re
the
capa
cito
r’s n
egat
ive
lead
goe
s to
ey
elet
16 .
S
TE
P 7
7
Inst
all a
no
ther
25
μF
cap
+ a
2.2
K
resi
sto
r, s
old
ered
to
get
her
Wra
p th
e le
ads
from
the
2 .2
K re
sist
or
aro
un
d t
he
lead
s o
n t
he
25μ
F 50
V ca
paci
tor a
nd so
lder
them
toge
ther
. Not
e th
e po
larit
y of
the
capa
cito
r .
Inst
all t
his
resi
stor
/cap
acito
r as
sem
bly
betw
een
eyel
ets
16 a
nd 9
0, m
akin
g su
re
the
capa
cito
r’s n
egat
ive
lead
goe
s to
ey
elet
16 .
S
TE
P 7
8
Ad
d t
hre
e ju
mp
ers
Cut a
4-1
/2" y
ello
w ju
mpe
r . Tu
rn th
e bo
ard
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 43 .
Run
the
othe
r end
of
this
jum
per u
p th
roug
h ho
le 7
2 an
d pu
ll it
tight
so
it st
ays
in p
lace
.
Add
a 4
" yel
low
jum
per t
o ey
elet
91 .
Add
a 2
-3/4
" yel
low
jum
per t
o ey
elet
90 .
S
TE
P 7
9
Ad
d .0
033
μF
cap
+ o
ne
resi
sto
rA
dd a
.003
3μF
Ora
nge
Dro
p ca
paci
tor
betw
een
eyel
ets
42 a
nd 8
9 .
Add
a 1
00K
resi
stor
bet
wee
n ey
elet
s 56
an
d 89
.
S
TE
P 8
0
Ad
d o
ne
resi
sto
r +
on
e ca
pac
ito
rA
dd a
100
K re
sist
or b
etw
een
eyel
ets
56
and
87 .
Ad
d a
.1μ
F O
ran
ge
Dro
p c
apac
ito
r be
twee
n ey
elet
s 55
and
87 .
91
16
+
25μ
F
Posi
tive
Neg
ativ
e
16
90
+25
μF
Posi
tive
Neg
ativ
e
stew
mac
.com
3
0
©20
19 S
tew
Mac
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
10pF
+25µF
+25µF
.01μF .01μF .02μF
stew
mac
.com
3
1
©20
19 S
tew
Mac
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
10pF
+25µF
+25µF
.01μF .01μF .02μF
S
TE
P 8
1
Ad
d t
wo
jum
per
sCu
t a
9" y
ello
w ju
mpe
r . Tu
rn t
he b
oard
ov
er a
nd w
rap
this
jum
per
thro
ugh
the
bott
om o
f eye
let 4
2 . R
un th
e ot
her e
nd o
f th
is ju
mpe
r up
thro
ugh
hole
13
and
pull
it tig
ht s
o it
stay
s in
pla
ce .
Add
a 2
-1/2
" yel
low
jum
per t
o ey
elet
89 .
S
TE
P 8
2
Ad
d t
wo
jum
per
sCu
t a 6
-1/4
" yel
low
jum
per .
Turn
the
boar
d ov
er a
nd w
rap
this
jum
per
thro
ugh
the
bott
om o
f eye
let
55 . R
un t
he o
ther
end
of
thi
s ju
mpe
r up
thr
ough
hol
e 13
and
pu
ll it
tight
so
it st
ays
in p
lace
.
Add
a 2
-1/4
" yel
low
jum
per t
o ey
elet
87 .
S
TE
P 8
3
Ad
d 1
0p
F ca
p +
on
e re
sist
or
Add
a 1
0pF
capa
cito
r and
a 3
.3M
resi
stor
be
twee
n ey
elet
s 15
and
41 .
S
TE
P 8
4
Ad
d t
wo
res
isto
rsA
dd a
470
K re
sist
or b
etw
een
eyel
ets
14
and
41 .
Add
a 2
20K
resi
stor
bet
wee
n ey
elet
s 12
an
d 41
.
S
TE
P 8
5
Inst
all a
25
μF
cap
+ a
n 8
20Ω
re
sist
or,
so
lder
ed t
og
eth
erW
rap
the
lead
s fr
om t
he 8
20Ω
res
isto
r ar
ou
nd
th
e le
ads
on
th
e 25
μF
50V
capa
cito
r and
sold
er th
em to
geth
er . N
ote
the
pola
rity
of th
e ca
paci
tor .
Inst
all t
his
asse
mbl
y be
twee
n ey
elet
s 12
and
86,
mak
ing
sure
the
cap
acito
r’s
nega
tive
lead
goe
s to
eye
let 1
2 .
S
TE
P 8
6
Inst
all a
no
ther
25
μF
cap
+ a
2.7
K
resi
sto
r, s
old
ered
to
get
her
Wra
p th
e le
ads
from
the
2 .7
K re
sist
or
aro
un
d t
he
lead
s o
n t
he
25μ
F 50
V ca
paci
tor a
nd so
lder
them
toge
ther
. Not
e th
e po
larit
y of
the
capa
cito
r .
Inst
all t
his
asse
mbl
y be
twee
n ey
elet
s 12
and
85,
mak
ing
sure
the
cap
acito
r’s
nega
tive
lead
goe
s to
eye
let 1
2 .
S
TE
P 8
7
Ad
d fo
ur
jum
per
sCu
t a 3
-1/2
" yel
low
jum
per .
Turn
the
boar
d ov
er a
nd w
rap
this
jum
per
thro
ugh
the
bott
om o
f eye
let
41 . R
un t
he o
ther
end
of
thi
s ju
mpe
r up
thr
ough
hol
e 70
and
pu
ll it
tight
so
it st
ays
in p
lace
.
Cut a
9-1
/2" y
ello
w ju
mpe
r . Tu
rn th
e bo
ard
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 14
. Run
the
oth
er e
nd
of t
his
jum
per
up t
hrou
gh h
ole
13 a
nd
pull
it tig
ht s
o it
stay
s in
pla
ce .
Add
a 1
-3/4
" yel
low
jum
per t
o ey
elet
86 .
Add
a 3
" yel
low
jum
per t
o ey
elet
85 .
S
TE
P 8
8
Ad
d t
hre
e re
sist
ors
Add
a 1
M r
esis
tor
betw
een
eyel
ets
11
and
54 .
Add
a 1
M r
esis
tor
betw
een
eyel
ets
11
and
34 .
Add
a 2
.2M
res
isto
r be
twee
n ey
elet
s 10
an
d 11
.
S
TE
P 8
9
Ad
d t
hre
e ca
pac
ito
rs
Add
a .0
1μF
cera
mic
dis
k ca
p be
twee
n ey
elet
s 34
and
54 .
Add
a .0
1μF
cera
mic
dis
k ca
p be
twee
n ey
elet
s 54
and
68 .
Add
a .0
2μF
cera
mic
dis
k ca
p be
twee
n ey
elet
s 68
and
83 .
S
TE
P 9
0
Ad
d fo
ur
jum
per
sCu
t a 6
-1/2
" yel
low
jum
per .
Turn
the
boar
d ov
er a
nd w
rap
this
jum
per
thro
ugh
the
bott
om o
f eye
let 1
1 . R
un th
e ot
her e
nd o
f th
is ju
mpe
r up
thro
ugh
hole
84
and
pull
it tig
ht s
o it
stay
s in
pla
ce .
Cut a
4-1
/2" y
ello
w ju
mpe
r . W
rap
one
end
thro
ugh
eyel
et 3
4 an
d ru
n th
e ot
her e
nd
dow
n th
roug
h ho
le 4
0 . F
lip t
he b
oard
ov
er, p
ull t
his
jum
per
back
up
thro
ugh
hole
84
and
pull
it tig
ht to
kee
p it
in p
lace
.
Cut
a 3"
yel
low
jum
per .
Turn
the
boa
rd
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 54 .
Run
the
othe
r end
of
this
jum
per u
p th
roug
h ho
le 6
9 an
d pu
ll it
tight
so
it st
ays
in p
lace
.
Add
a 2
-1/2
" yel
low
jum
per t
o ey
elet
83 .
86
12
+25
μF
Posi
tive
Neg
ativ
e
12
85
+
25μ
F
Posi
tive
Neg
ativ
e
stew
mac
.com
3
2
©20
19 S
tew
Mac
67
8
5152
10 34
54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9981
8279
80
675333
9
84
6970
7172
59
57
7374
40
1320
2227
1817
2524
382812
34
5
7677
78
29
46 64
39 4748
30
6566
75
+25µF
102J 1119
stew
mac
.com
3
3
©20
19 S
tew
Mac
67
8
5152
10 34
54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9981
8279
80
675333
9
84
6970
7172
59
57
7374
40
1320
2227
1817
2524
382812
34
5
7677
78
29
46 64
39 4748
30
6566
75
+25µF
102J 1119
S
TE
P 9
1
Ad
d t
wo
jum
per
sCu
t a 1
0" y
ello
w ju
mpe
r . W
rap
one
end
thro
ugh
eyel
et 6
8 an
d ru
n th
e ot
her
end
dow
n th
roug
h ho
le 5
3 . F
lip t
he
boar
d ov
er, p
ull t
his
jum
per
back
up
thro
ugh
hole
33
and
pull
it tig
ht to
kee
p it
in p
lace
.
Cu
t an
9-1
/2"
yello
w j
um
per
. Tu
rn
the
boar
d ov
er a
nd w
rap
this
jum
per
thro
ugh
the
bott
om o
f ey
elet
10 .
Run
th
e ot
her e
nd o
f thi
s jum
per u
p th
roug
h ho
le 9
and
pul
l it ti
ght s
o it
stay
s in
plac
e .
S
TE
P 9
2
Ad
d t
hre
e re
sist
ors
Add
a 2
20K
resi
stor
bet
wee
n ey
elet
s 82
and
83 .
Add
a 1
00K
resi
stor
bet
wee
n ey
elet
s 52
and
82 .
Add
a 1
0M re
sist
or b
etw
een
eyel
ets
51
and
82 .
S
TE
P 9
3
Inst
all t
he
op
toco
up
ler
Orie
nt th
e op
toco
uple
r as
show
n in
the
wiri
ng d
iagr
am, w
ith t
he s
ide
with
the
do
t bet
wee
n ey
elet
s 51
and
52 . W
rap
one
lead
of t
he d
ot s
ide
of t
he o
ptoc
oupl
er
thro
ugh
eyel
et 5
1 an
d th
e ot
her l
ead
from
th
at s
ide
thro
ugh
eyel
et 5
2 . W
rap
the
othe
r end
's le
ads t
hrou
gh e
yele
ts 7
and
8 .
This
lit
tle
devi
ce is
wha
t co
ntro
ls t
he
vibr
ato
for t
he a
mp .
The
end
with
the
dot
has
an L
ED a
nd th
e ot
her e
nd is
a li
ght-
depe
nden
t re
sist
or . T
he s
peed
con
trol
de
term
ines
the
fre
quen
cy a
t w
hich
the
LE
D f
lash
es, a
nd t
he in
tens
ity
cont
rol
det
erm
ines
how
muc
h of
th
e gu
itar
si
gnal
is a
ffect
ed b
y th
e lig
ht-d
epen
dent
re
sist
or .
S
TE
P 9
4
Ad
d t
hre
e ju
mp
ers
Cut a
10"
yel
low
jum
per .
Turn
the
boar
d ov
er a
nd w
rap
this
jum
per
thro
ugh
the
bott
om o
f eye
let 8
. Run
the
othe
r end
of
this
jum
per u
p th
roug
h ho
le 9
and
pul
l it
tight
so
it st
ays
in p
lace
.
Cut a
3-1
/4" y
ello
w ju
mpe
r . Tu
rn th
e bo
ard
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 51
. Run
the
oth
er e
nd
of t
his
jum
per
up t
hrou
gh h
ole
67 a
nd
pull
it tig
ht s
o it
stay
s in
pla
ce .
Add
a 1
/2"
bare
wire
bet
wee
n ey
elet
s 6
and
7 .
S
TE
P 9
5
Inst
all a
no
ther
25
μF
cap
+ a
10
0K
re
sist
or,
so
lder
ed t
og
eth
erW
rap
the
lead
s fr
om t
he 1
00K
resi
stor
ar
ou
nd
th
e le
ads
on
th
e 25
μF
50V
capa
cito
r and
sold
er th
em to
geth
er . N
ote
the
pola
rity
of th
e ca
paci
tor .
Inst
all t
his
asse
mbl
y be
twee
n ey
elet
s 6
and
81, m
akin
g su
re t
he c
apac
itor’s
ne
gativ
e le
ad g
oes
to e
yele
t 6 .
S
TE
P 9
6
Ad
d t
hre
e re
sist
ors
Add
a 4
7Ω r
esis
tor
betw
een
eyel
ets
5 an
d 6 .
Add
a 2
20K
resi
stor
bet
wee
n ey
elet
s 32
an
d 50
.
Add
a 2
20K
resi
stor
bet
wee
n ey
elet
s 31
an
d 50
.
S
TE
P 9
7
Inst
all t
hre
e re
sist
ors
+ o
ne
cap
acit
or
Add
a 1
M r
esis
tor
betw
een
eyel
ets
49
and
80 .
Add
a 4
70Ω
resi
stor
bet
wee
n ey
elet
s 49
an
d 79
.
Add
ano
ther
1M
resi
stor
bet
wee
n ey
elet
s 49
and
78 .
Add
a .0
01μF
Ora
nge
Dro
p ca
p be
twee
n ey
elet
s 50
and
80 .
81
6
+
25μ
F
Posi
tive
Neg
ativ
e
stew
mac
.com
3
4
©20
19 S
tew
Mac
38
28
12
34
56
78
5152
10 34
54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
675333
9
84
6970
7172
59
57
7374
40
1320
2227
1817
2524
75
104J 600V
104J 600V
104J 600V
stew
mac
.com
3
5
©20
19 S
tew
Mac
38
28
12
34
56
78
5152
10 34
54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
675333
9
84
6970
7172
59
57
7374
40
1320
2227
1817
2524
75
104J 600V
104J 600V
104J 600V
ST
EP
98
Ad
d t
wo
res
isto
rs +
on
e ca
pac
ito
rA
dd a
22K
resi
stor
bet
wee
n ey
elet
5 a
nd
49 .
Add
an
820Ω
res
isto
r be
twee
n ey
elet
s 5
and
48 .
Add
a .1
μF O
rang
e D
rop
cap
betw
een
eyel
ets
5 an
d 78
.
S
TE
P 9
9
Ad
d t
hre
e ju
mp
ers
Add
a 2
-1/4
" yel
low
jum
per t
o ey
elet
81 .
Add
a 3
" yel
low
jum
per t
o ey
elet
80 .
Cut a
n 11
" yel
low
jum
per .
Turn
the
boar
d ov
er a
nd w
rap
this
jum
per
thro
ugh
the
bott
om o
f eye
let
32 . R
un t
he o
ther
end
of
this
jum
per u
p th
roug
h ho
le 9
and
pul
l it
tight
so
it st
ays
in p
lace
.
S
TE
P 1
00
Ad
d t
hre
e m
ore
jum
per
sA
dd a
2" y
ello
w ju
mpe
r to
eyel
et 7
9 .
Add
a 2
" yel
low
jum
per t
o ey
elet
78 .
Cut
an 8
-1/2
" ye
llow
jum
per .
Turn
the
bo
ard
over
and
wra
p th
is ju
mpe
r thr
ough
th
e bo
ttom
of e
yele
t 48
. Run
the
oth
er
end
of t
his
jum
per
up t
hrou
gh h
ole
66
and
pull
it tig
ht s
o it
stay
s in
pla
ce .
S
TE
P 1
01
Ad
d fo
ur
resi
sto
rsA
dd a
n 82
K re
sist
or b
etw
een
eyel
ets
47
and
77 .
Add
a 1
00K
resi
stor
bet
wee
n ey
elet
s 47
an
d 76
.
Add
a 2
20K
resi
stor
bet
wee
n ey
elet
s 3
and
39 .
Add
a 2
20K
resi
stor
bet
wee
n ey
elet
s 4
and
39 .
S
TE
P 1
02
Ad
d t
wo
.1μ
F ca
ps
Add
a .1
μF O
rang
e D
rop
cap
betw
een
eyel
ets
4 an
d 77
.
Ad
d a
not
her
.1μ
F O
ran
ge
Dro
p c
ap
betw
een
eyel
ets
3 an
d 76
.
S
TE
P 1
03
Ad
d fo
ur
jum
per
sA
dd a
4" y
ello
w ju
mpe
r to
eyel
et 7
7 .
Add
a 3
-1/4
" yel
low
jum
per t
o ey
elet
76 .
Cut a
6-1
/2" y
ello
w ju
mpe
r . Tu
rn th
e bo
ard
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 4 . R
un th
e ot
her e
nd o
f th
is ju
mpe
r up
thro
ugh
hole
65
and
pull
it tig
ht s
o it
stay
s in
pla
ce .
Cut
a 7"
yel
low
jum
per .
Turn
the
boa
rd
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 3 . R
un th
e ot
her e
nd o
f th
is ju
mpe
r up
thro
ugh
hole
65
and
pull
it tig
ht s
o it
stay
s in
pla
ce .
S
TE
P 1
04
Ad
d t
hre
e ju
mp
ers
Cut a
3-3
/4" y
ello
w ju
mpe
r . Tu
rn th
e bo
ard
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 39
. Run
the
oth
er e
nd
of t
his
jum
per
up t
hrou
gh h
ole
30 a
nd
pull
it tig
ht s
o it
stay
s in
pla
ce .
Add
a 3
/4"
bare
wire
bet
wee
n ey
elet
s 2
and
29 .
Add
ano
ther
3/4
" b
are
wir
e b
etw
een
eyel
ets
46 a
nd 6
4 .
S
TE
P 1
05
Ad
d fo
ur
mo
re ju
mp
ers
Cut a
7-1
/2" y
ello
w ju
mpe
r . Tu
rn th
e bo
ard
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 64 .
Run
the
othe
r end
of
this
jum
per u
p th
roug
h ho
le 7
5 an
d pu
ll it
tight
so
it st
ays
in p
lace
.
Cut
a 4"
yel
low
jum
per .
Turn
the
boa
rd
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 29
. Run
the
oth
er e
nd
of t
his
jum
per
up t
hrou
gh h
ole
38 a
nd
pull
it tig
ht s
o it
stay
s in
pla
ce .
Cut a
7-3
/4" y
ello
w ju
mpe
r . Tu
rn th
e bo
ard
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 1 . R
un th
e ot
her e
nd o
f th
is ju
mpe
r up
thro
ugh
hole
28
and
pull
it tig
ht s
o it
stay
s in
pla
ce .
Cut
anot
her
7-3/
4" y
ello
w ju
mpe
r . Tu
rn
the
boar
d ov
er a
nd a
lso
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 1 . R
un th
e ot
her e
nd o
f thi
s jum
per u
p th
roug
h ho
le
28 a
nd p
ull i
t tig
ht s
o it
stay
s in
pla
ce .
Your
min
d is
not
pla
ying
tric
ks o
n yo
u he
re; y
ou r
eally
nee
d tw
o ju
mp
ers
of
the
sam
e le
ngth
com
ing
from
eye
let
1 th
roug
h ho
le 2
8 .
stew
mac
.com
3
6
©20
19 S
tew
Mac
38
28
12
34
56
78
5152
10 34
54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
675333
9
84
6970
7172
59
57
7374
40
1320
2227
1817
2524
75
stew
mac
.com
3
7
©20
19 S
tew
Mac
38
28
12
34
56
78
5152
10 34
54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
675333
9
84
6970
7172
59
57
7374
40
1320
2227
1817
2524
75 S
TE
P 1
06
Two
flyi
ng
jum
per
sFl
ying
jum
pers
are
wire
s th
at tr
avel
ove
r th
e bo
ard,
jum
ping
fro
m o
ne e
yele
t to
an
othe
r . Th
ese
are
very
com
mon
in cl
assi
c po
int-
to-p
oint
circ
uits
.
The
first
flyi
ng ju
mpe
r is
the
one
you'
ve
inst
alle
d co
min
g fr
om h
ole
22 . I
t ne
eds
to ru
n to
the
left
, alo
ng th
e to
p ed
ge o
f th
e ey
elet
boa
rd u
ntil
it ge
ts to
hol
e 13
. Th
ere
it w
ill b
e tw
iste
d in
line
with
the
be
hind
-the
-boa
rd le
ad f
rom
eye
let
55,
com
ing
thro
ugh
hole
13 .
S
TE
P 1
07
Twis
tin
g fl
yin
g ju
mp
ers
Care
fully
twis
t the
se tw
o fly
ing
jum
pers
to
geth
er to
war
d th
e le
ft si
de o
f the
boa
rd
whi
le m
akin
g su
re n
ot t
o di
stur
b th
eir
wra
pped
con
nect
ions
on
the
eyel
ets .
Yo
u w
ant
the
lead
s to
be
up a
nd a
way
fr
om c
ompo
nent
s . S
top
twis
ting
them
to
geth
er o
nce
you
are
abov
e ey
elet
s 31
an
d 32
. The
y w
ill b
e co
nnec
ting
to th
ese
eyel
ets .
S
TE
P 1
08
Inst
alli
ng
flyi
ng
jum
per
sU
se a
mul
timet
er to
find
the
flyin
g ju
mpe
r w
ith co
ntin
uity
to e
yele
t 23 .
Wra
p th
e fr
ee
end
of th
at ju
mpe
r to
eyel
et 3
1 .
The
othe
r fl
ying
jum
per
sho
uld
have
co
ntin
uity
to e
yele
t 55 .
Wra
p th
e fr
ee e
nd
of th
is ju
mpe
r to
eyel
et 3
2 .
S
TE
P 1
09
Ad
d t
hre
e b
ehin
d-t
he-
bo
ard
ju
mp
ers
Cut a
2-3
/4" y
ello
w ju
mpe
r . Tu
rn th
e bo
ard
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 35 .
Wra
p th
e ot
her e
nd
of t
his
jum
per
thro
ugh
the
bott
om o
f ey
elet
62 .
Cut a
3-1
/4" y
ello
w ju
mpe
r . Tu
rn th
e bo
ard
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 35 .
Wra
p th
e ot
her e
nd
of t
his
jum
per
thro
ugh
the
bott
om o
f ey
elet
56 .
Cut a
2-1
/4" y
ello
w ju
mpe
r . Tu
rn th
e bo
ard
over
and
wra
p th
is ju
mpe
r th
roug
h th
e bo
ttom
of e
yele
t 15 .
Wra
p th
e ot
her e
nd
of t
his
jum
per
thro
ugh
the
bott
om o
f ey
elet
58 .
S
TE
P 1
10
Ad
d fo
ur
jum
per
sCu
t a
6" y
ello
w j
ump
er a
nd a
n 8-
1/4"
ye
llow
jum
per
. Mar
k th
e en
ds o
f th
e 6"
wire
with
a b
lack
mar
ker .
Pass
bot
h w
ires d
own
thro
ugh
hole
27
and
back
up
thro
ugh
hole
74 .
Cut t
wo
11" y
ello
w ju
mpe
rs a
nd m
ark
the
ends
of o
ne w
ith a
bla
ck m
arke
r . Pa
ss b
oth
wire
s dow
n th
roug
h ho
le 2
0 an
d ba
ck u
p th
roug
h ho
le 7
3 .
S
TE
P 1
11
Ad
d fo
ur
gro
un
d ju
mp
ers
Cut f
our 3
" gre
en ju
mpe
rs .
Add
the
first
to e
yele
t 21 .
Add
the
seco
nd to
eye
let 1
6 .
Add
the
third
to e
yele
t 12 .
Add
the
four
th to
eye
let 6
.
Sto
p a
nd
rev
iew
Now
all
the
com
pone
nts a
nd w
ires a
re o
n th
e ey
elet
boa
rd . S
top
and
take
a b
reak
so
you
’ll h
ave
fres
h ey
es t
o re
view
you
r w
ork
befo
re s
olde
ring .
Mak
e su
re y
ou’v
e fo
llow
ed e
ach
step
co
rrec
tly . I
t w
ould
be
surp
risin
g to
find
no
mis
take
s at
thi
s po
int,
and
it’s
muc
h le
ss w
ork
to fi
nd a
nd fi
x th
em n
ow ra
ther
th
an a
fter
sol
derin
g!
As
you’
re c
heck
ing
your
wor
k, m
ake
sure
all
your
con
nect
ions
are
tigh
t . D
on’t
coun
t on
sol
der
to “
glue
” yo
ur jo
ints
—
mak
e th
em m
echa
nica
lly t
ight
bef
ore
sold
er is
eve
r app
lied .PA
USE
stew
mac
.com
3
8
©20
19 S
tew
Mac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
4 3
21
87
65
4 3
21
87
65
4 3
21
87
65
Insu
lato
rB
oard
Insu
lato
rB
oard
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
AB
CD
FE
104J 600V
104J 600V
473J 600V
473J 600V
+25µF
+25µF
473J 600V
250
222J 600V
332J 600V
+25µF
510+
+25µF
+25µF
102J 1119
10pF
+25µF
+25µF
104J 600V
104J 600V
.01μF .01μF .02μF
104J 600V
104J 600V
250
+
25µ
F
stew
mac
.com
3
9
©20
19 S
tew
Mac
S
TE
P 1
12
Sold
er t
he
com
po
nen
ts
on
th
e ey
elet
bo
ard
sN
ow th
at th
e co
mpo
nent
s an
d ju
mpe
rs
are
on t
he b
oard
s an
d do
uble
-che
cked
fo
r cor
rect
pla
cem
ent,
its ti
me
to s
et th
e co
nnec
tions
with
sold
er . R
evie
w "T
ips f
or
grea
t sol
derin
g" o
n pa
ge 1
1 .
Aft
er a
ll th
e jo
ints
are
sol
dere
d, c
lip th
e ex
cess
lead
s on
the
fron
t and
bac
k of
the
boar
ds . T
rimm
ing
the
exce
ss is
impo
rtan
t to
avo
id a
sho
rt in
you
r circ
uit .
Chec
k al
l you
r so
lder
join
ts t
o se
e th
at
they
’re s
hiny
and
to m
ake
sure
that
you
ha
ven’
t mis
sed
one .
S
TE
P 1
13
Inst
all a
ll t
hre
e ey
elet
bo
ard
s,
bac
ked
by
thei
r in
sula
tor
bo
ard
sBe
fore
inst
allin
g th
e m
ain
eyel
et b
oard
an
d in
sula
tor b
oard
in th
e ch
assi
s, m
ake
sure
you
hav
e en
ough
len
gth
on t
he
unso
lder
ed j
ump
ers
com
ing
thro
ugh
hole
s 27
and
74,
and
hol
es 2
0 an
d 73
, to
reac
h th
eir
com
pone
nts .
The
bes
t w
ay
to d
o th
is is
to
lay
the
eyel
et b
oard
on
the
floor
of
the
chas
sis
whe
re it
will
be
mou
nted
and
adj
ust t
hese
jum
pers
unt
il th
ey re
ach
thei
r com
pone
nts .
To in
stal
l th
e m
ain
eyel
et b
oard
, fir
st
lay
the
mai
n in
sula
tion
boa
rd o
n th
e bo
ttom
of
the
chas
sis,
alig
ning
it w
ith
the
mou
ntin
g ho
les .
Run
a 6
-32
x 1/
2"
mac
hine
scre
w th
roug
h th
e ey
elet
boa
rd,
the
insu
latio
n bo
ard
and
thro
ugh
the
chas
sis .
Sec
ure
it w
ith a
lock
nut
on t
he
outs
ide
of th
e ch
assi
s . D
o th
e sa
me
with
th
e se
cond
bol
t .
Inst
all t
he b
ias b
oard
in th
e sa
me
man
ner:
insu
latio
n bo
ard
dow
n fir
st, e
yele
t boa
rd
on t
op, m
ount
ed w
ith t
wo
sets
of
6-32
ha
rdw
are .
To i
nsta
ll th
e fi
lter
cap
eye
let
boa
rd,
flip
the
chas
sis
over
. Run
the
jum
pers
th
roug
h th
e ey
elet
boa
rd a
nd t
hrou
gh
the
insu
latio
n bo
ard
and
then
alig
n th
e fil
ter c
ap b
oard
with
the
grom
met
s an
d pa
ss th
e ju
mpe
rs th
roug
h th
e gr
omm
ets .
This
filte
r ca
p ey
elet
boa
rd w
ill n
ot b
e m
ount
ed w
ith s
crew
s bu
t rat
her h
eld
on
by th
e ju
mpe
r wire
s . O
nce
you
have
the
boar
ds f
lush
with
the
bac
k si
de o
f th
e ch
assi
s, b
end
the
jum
pers
ove
r ins
ide
the
chas
sis t
o ke
ep th
e bo
ard
tight
to th
e ba
ck
of th
e ch
assi
s .
Insu
lato
r boa
rd
G
NH
OI
PJ
RK
SLM
Q
16μF
16μF
16μF
16μF
16μF
stew
mac
.com
4
0
©20
19 S
tew
Mac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4A
BC
D
FE
4 3
21
87
65
4 3
21
87
65
4 3
21
87
65
250KA
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
250KA
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
stew
mac
.com
4
1
©20
19 S
tew
Mac
S
TE
P 1
14
Sold
er t
he
filt
er c
ap b
oar
d ju
mp
ers
Pull
the
two
jum
pers
com
ing
thro
ugh
the
grom
met
ed h
ole
betw
een
tube
sock
et V
4 an
d tu
be s
ocke
t V5
until
they
are
tigh
t .
Sold
er o
ne o
f the
se ju
mpe
rs to
eye
let 8
2 .
Sold
er th
e ot
her j
umpe
r to
eyel
et 8
8 .
S
TE
P 1
15
Sold
er t
he
filt
er c
ap b
oar
d ju
mp
ers,
co
nt.
Pull
the
two
jum
pers
com
ing
thro
ugh
the
grom
met
ed h
ole
behi
nd th
e no
rmal
ch
anne
l bas
s po
t unt
il th
ey a
re ti
ght .
Sold
er th
e ye
llow
jum
per t
o ey
elet
35 .
Sold
er t
he g
reen
jum
per
to t
he b
ack
of
the
norm
al c
hann
el b
ass
pot .
S
TE
P 1
16
Sold
er t
he
filt
er c
ap b
oar
d ju
mp
ers,
co
nt.
Sold
er fi
lter c
ap b
oard
jum
pers
, con
t .
Pull
the
four
jum
pers
com
ing
thro
ugh
the
grom
met
ed h
ole
behi
nd th
e vi
brat
o ch
anne
l tre
ble
pot u
ntil
they
are
tigh
t .
Sold
er t
he g
reen
jum
per
to t
he b
ack
of
the
vibr
ato
chan
nel t
rebl
e po
t .
Sold
er t
he j
ump
er w
ith
cont
inui
ty t
o ey
elet
L to
eye
let 1
.
Sold
er t
he j
ump
er w
ith
cont
inui
ty t
o ey
elet
J to
eye
let 2
.
Sold
er t
he j
ump
er w
ith
cont
inui
ty t
o ey
elet
I to
eye
let 4
7 . Y
ou w
ill h
ave
to ru
n th
is ju
mpe
r und
erne
ath
the
.1μF
Ora
nge
Dro
p ca
p in
stal
led
betw
een
eyel
ets
4 an
d 77
.
S
TE
P 1
17
Sold
er t
ub
e so
cket
V9
Wra
p on
e of
the
7-3
/4"
yello
w ju
mpe
rs
from
hol
e 28
to p
in 8
on
tube
soc
ket V
9 al
ong
with
the
yello
w p
ower
tran
sfor
mer
le
ad .
Sold
er a
ll co
nnec
tions
to th
is so
cket
(five
w
ires)
and
trim
the
exce
ss w
ire e
nds .
S
TE
P 1
18
Sold
er t
ub
e so
cket
V8
Test
the
two
jum
pers
com
ing
from
hol
e 65
to
iden
tify
the
one
with
con
tinui
ty
to e
yele
t 3 . W
rap
this
jum
per t
o pi
n 1
of
tube
soc
ket V
8 .
Sold
er a
ll co
nnec
tions
to th
is so
cket
(five
w
ires,
four
resi
stor
lead
s) a
nd tr
im e
xces
s w
ire e
nds .
S
TE
P 1
19
Sold
er t
ub
e so
cket
V7
Test
the
rem
aini
ng ju
mpe
r com
ing
from
ho
le 6
5 to
mak
e su
re it
has
con
tinui
ty
to e
yele
t 4 . W
rap
this
jum
per t
o pi
n 1
of
tube
soc
ket V
7 .
Wra
p th
e ye
llow
jum
per f
rom
hol
e 38
to
pin
6 of
tub
e so
cket
V7
alon
g w
ith t
he
resi
stor
lead
in p
lace
.
Sold
er a
ll co
nnec
tions
to th
is so
cket
(five
w
ires,
four
resi
stor
lead
s) a
nd tr
im e
xces
s w
ire e
nds .
S
TE
P 1
20
Sold
er t
ub
e so
cket
V6
Wra
p th
e ju
mpe
r fro
m e
yele
t 76
to p
in 6
of
the
V6 tu
be s
ocke
t .
Wra
p th
e ju
mpe
r fro
m e
yele
t 77
to p
in 1
of
the
V6 tu
be s
ocke
t .
Wra
p th
e ju
mpe
r fro
m e
yele
t 78
to p
in 7
of
the
V6 tu
be s
ocke
t .
Wra
p th
e ju
mpe
r fr
om e
yele
t 79
to
pin
8 of
the
V6
tube
soc
ket
alon
g w
ith t
he
jum
per a
lread
y in
pla
ce .
Wra
p th
e ju
mpe
r fro
m e
yele
t 80
to p
in 2
of
the
V6 tu
be s
ocke
t .
Sold
er th
e co
nnec
tions
to th
is so
cket
(six
w
ires)
and
trim
the
exce
ss w
ire e
nds .
stew
mac
.com
4
2
©20
19 S
tew
Mac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4A
BC
D
FE
6
4321
98 7 5
4 3
21
87
65
4 3
21
87
65
4 3
21
87
65
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
stew
mac
.com
4
3
©20
19 S
tew
Mac
S
TE
P 1
21
Sold
er t
ub
e so
cket
V5
Wra
p th
e ju
mpe
r fro
m h
ole
67 to
pin
6 o
f th
e V5
tube
soc
ket .
Wra
p th
e ju
mpe
r fro
m e
yele
t 83
to p
in 1
of
the
V5 tu
be s
ocke
t .
Mak
e su
re th
e ju
mpe
r com
ing
from
hol
e 69
has
con
tinui
ty to
eye
let 5
4 . W
rap
this
ju
mpe
r to
pin
7 of
the
V5 tu
be s
ocke
t .
Wra
p th
e ju
mpe
r fro
m e
yele
t 81
to p
in 8
of
the
V5 tu
be s
ocke
t .
Test
the
two
jum
pers
com
ing
from
hol
e 84
to id
entif
y th
e on
e w
ith c
ontin
uity
to
eyel
et 3
4 . W
rap
this
jum
per
to p
in 2
of
tube
soc
ket V
5 .
Wra
p th
e ju
mpe
r fro
m e
yele
t 85
to p
in 3
of
tube
soc
ket V
5 .
Sold
er th
e co
nnec
tions
to th
is so
cket
(six
w
ires)
and
trim
the
exce
ss w
ire e
nds .
S
TE
P 1
22
Sold
er t
ub
e so
cket
V4
Wra
p th
e ju
mpe
r fro
m e
yele
t 87
to p
in 6
of
the
V4 tu
be s
ocke
t .
Wra
p th
e ju
mpe
r fro
m e
yele
t 89
to p
in 1
of
the
V4 tu
be s
ocke
t .
Wra
p th
e ju
mpe
r fro
m h
ole
70 to
pin
7 o
f th
e V4
tube
soc
ket .
Wra
p th
e ju
mpe
r fr
om e
yele
t 86
to
pin
8 of
the
V4 tu
be s
ocke
t with
the
jum
per
alre
ady
in p
lace
.
Sold
er th
e co
nnec
tions
to th
is so
cket
(six
w
ires)
and
trim
the
exce
ss w
ire e
nds .
S
TE
P 1
23
Sold
er t
ub
e so
cket
V3
Wra
p th
e ju
mpe
r fr
om h
ole
72 t
o pi
n 7
of t
he V
3 tu
be s
ocke
t w
ith t
he ju
mpe
r al
read
y in
pla
ce .
Wra
p th
e ju
mpe
r fr
om e
yele
t 90
to
pin
8 of
the
V3 tu
be s
ocke
t with
the
jum
per
alre
ady
in p
lace
.
Sold
er th
e co
nnec
tions
to th
is so
cket
(six
w
ires)
and
trim
the
exce
ss w
ire e
nds .
S
TE
P 1
24
Sold
er t
ub
e so
cket
V2
Wra
p th
e ju
mpe
r fro
m e
yele
t 92
to p
in 6
of
the
V2 tu
be s
ocke
t .
Wra
p th
e ju
mpe
r fro
m e
yele
t 93
to p
in 1
of
the
V2 tu
be s
ocke
t .
Wra
p th
e un
mar
ked
jum
per f
rom
hol
e 73
to
pin
7 o
f the
V2
tube
soc
ket .
Wra
p th
e m
arke
d ju
mpe
r fro
m h
ole
73 to
pi
n 2
of th
e V2
tube
soc
ket .
Wra
p th
e ju
mpe
r fr
om e
yele
t 91
to
pin
8 of
the
V2 tu
be s
ocke
t with
the
jum
per
alre
ady
in p
lace
.
Wra
p th
e ju
mpe
r fro
m e
yele
t 95
to p
in 3
of
the
V2 tu
be s
ocke
t .
Sold
er th
e co
nnec
tions
to th
is so
cket
(six
w
ires)
and
trim
the
exce
ss w
ire e
nds .
S
TE
P 1
25
Sold
er t
ub
e so
cket
V1
Wra
p th
e ju
mpe
r fro
m e
yele
t 97
to p
in 6
of
the
V1 tu
be s
ocke
t .
Wra
p th
e ju
mpe
r fro
m e
yele
t 98
to p
in 1
of
the
V1 tu
be s
ocke
t .
Wra
p th
e un
mar
ked
jum
per f
rom
hol
e 74
to
pin
7 o
f the
V1
tube
soc
ket .
Wra
p th
e m
arke
d ju
mpe
r fro
m h
ole
74 to
pi
n 2
of th
e V1
tube
soc
ket .
Wra
p th
e ju
mpe
r fro
m e
yele
t 96
to p
in 3
of
the
V1 tu
be s
ocke
t .
Sold
er th
e co
nnec
tions
to th
is so
cket
(six
w
ires)
and
trim
the
exce
ss w
ire e
nds .
S
TE
P 1
26
Sold
er fo
ur
jum
per
s to
co
mp
on
ents
on
th
e b
ack
pan
elTh
e la
st u
nsol
dere
d ju
mpe
r com
ing
from
ho
le 8
4 sh
ould
hav
e co
ntin
uity
to e
yele
t 11
. Sol
der t
his
jum
per t
o th
e m
iddl
e lu
g of
the
vibr
ato
peda
l RCA
jack
.
Sold
er t
he ju
mpe
r fr
om h
ole
66 t
o th
e rig
ht lu
g (ti
p co
nnec
tion)
of t
he e
xten
sion
sp
eake
r ja
ck a
long
with
the
jum
per
in
plac
e .
Sold
er th
e ot
her j
umpe
r fro
m h
ole
28 to
th
e le
ft lu
g of
the
stan
dby
switc
h .
Sold
er t
he ju
mpe
r fr
om h
ole
75 t
o th
e rig
ht lu
g of
the
stan
dby
switc
h .
S
TE
P 1
27
Sold
er t
he
no
rmal
ch
ann
el in
pu
t ja
cks
Slid
e 1"
of
1/8"
hea
t-sh
rink
tubi
ng o
ver
the
mar
ked
jum
per c
omin
g fr
om th
roug
h ho
le 2
7 . S
olde
r thi
s jum
per t
o th
e tw
iste
d pa
ir of
68k
resi
stor
lead
s com
ing
from
the
norm
al c
hann
el in
put
jack
s an
d ap
ply
heat
to
the
heat
-shr
ink
tubi
ng t
o se
al it
to
the
sold
er jo
int .
Sold
er th
e gr
een
jum
per f
rom
eye
let 2
1 to
the
left
lug
(shi
eld
conn
ectio
n) o
f the
in
put 2
jack
.
Sold
er a
ny u
nsol
dere
d re
sist
or le
ads i
nto
plac
e on
the
inpu
t jac
ks n
ow .
Trim
the
exce
ss w
ires .
stew
mac
.com
4
4
©20
19 S
tew
Mac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4A
BC
D
FE
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
4 3
21
87
65
4 3
21
87
65
4 3
21
87
65
1MA
1MA
250KA
250KA
100KL
250KA
250KL
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
stew
mac
.com
4
5
©20
19 S
tew
Mac
S
TE
P 1
28
Sold
er n
orm
al c
han
nel
vo
lum
e p
ot
Sold
er t
he u
nmar
ked
jum
per
com
ing
thro
ugh
hole
27
to th
e m
iddl
e lu
g of
the
volu
me
pot .
Cut
a 1”
gre
en ju
mpe
r an
d re
mov
e th
e in
sula
tion .
Ben
d th
is ju
mpe
r in
a “J
” sha
pe
and
run
it fr
om th
e le
ft lu
g of
the
volu
me
pot t
o th
e ba
ck o
f the
vol
ume
pot .
Sold
er
it in
bot
h pl
aces
.
S
TE
P 1
29
Sold
er n
orm
al c
han
nel
tre
ble
po
tFi
nd th
e ju
mpe
r com
ing
thro
ugh
hole
25
that
has
con
tinui
ty t
o ey
elet
45 .
Sol
der
this
jum
per t
o th
e rig
ht lu
g of
the
norm
al
chan
nel t
rebl
e po
t .
Sold
er t
he j
ump
ers
in t
he c
ente
r an
d le
ft lu
gs o
f the
treb
le p
ot if
you
hav
e no
t do
ne s
o .
S
TE
P 1
30
Sold
er n
orm
al c
han
nel
bas
s p
ot
Twis
t tog
ethe
r the
two
jum
pers
com
ing
from
hol
e 24
.
Find
the
jum
per c
omin
g th
roug
h ho
le 2
4 th
at h
as c
ontin
uity
to
eyel
et 2
6 . S
olde
r th
is j
ump
er t
o th
e m
iddl
e lu
g of
the
no
rmal
cha
nnel
bas
s po
t alo
ng w
ith th
e ju
mpe
r alre
ady
in p
lace
.
Find
the
jum
per c
omin
g th
roug
h ho
le 2
4 th
at h
as c
ontin
uity
to
eyel
et 3
7 . S
olde
r th
is ju
mpe
r to
the
left
lug
of th
e no
rmal
ch
anne
l bas
s po
t alo
ng w
ith th
e re
sist
or
lead
alre
ady
in p
lace
.
S
TE
P 1
31
Sold
er v
ibra
to c
han
nel
inp
ut
jack
sSl
ide
1" o
f 1/
8" h
eat-
shrin
k tu
bing
ove
r th
e m
arke
d ju
mpe
r com
ing
from
thro
ugh
hole
20 .
Sol
der t
his j
umpe
r to
the
twis
ted
pair
of 6
8K re
sist
or le
ads c
omin
g fr
om th
e vi
brat
o ch
anne
l inp
ut ja
cks
and
appl
y he
at t
o th
e he
at-s
hrin
k tu
bing
to
seal
it
to th
e so
lder
join
t .
Sold
er th
e gr
een
jum
per f
rom
eye
let 1
6 to
the
left
lug
(shi
eld
conn
ectio
n) o
f the
in
put 2
jack
.
Sold
er a
ny u
nsol
dere
d re
sist
or le
ads i
nto
plac
e on
the
inpu
t jac
ks n
ow .
Trim
the
exce
ss w
ires .
S
TE
P 1
32
Sold
er v
ibra
to c
han
nel
vo
lum
e p
ot
Sold
er t
he u
nmar
ked
jum
per
com
ing
thro
ugh
hole
20
to th
e m
iddl
e lu
g of
the
vibr
ato
chan
nel v
olum
e po
t al
ong
with
th
e ca
paci
tor l
ead
alre
ady
in p
lace
.
Cut
a 1”
gre
en ju
mpe
r an
d re
mov
e th
e in
sula
tion .
Ben
d th
is ju
mpe
r in
a “J
” sha
pe
and
run
it fr
om th
e le
ft lu
g of
the
volu
me
pot
to t
he b
ack
of t
he v
ibra
to c
hann
el
volu
me
pot .
Sold
er it
in b
oth
plac
es .
Als
o so
lder
the
gree
n ju
mpe
r fro
m e
yele
t 12
to
the
back
of
the
vibr
ato
chan
nel
volu
me
pot .
S
TE
P 1
33
Sold
er v
ibra
to c
han
nel
tre
ble
po
tFi
nd th
e ju
mpe
r com
ing
thro
ugh
hole
18
that
has
con
tinui
ty t
o ey
elet
44 .
Sol
der
this
jum
per t
o th
e rig
ht lu
g of
the
vibr
ato
chan
nel t
rebl
e po
t .
Sold
er th
e ju
mpe
rs in
the
cent
er a
nd le
ft
lugs
of t
he v
ibra
to c
hann
el t
rebl
e po
t if
you
have
not
don
e so
.
S
TE
P 1
34
Sold
er v
ibra
to c
han
nel
bas
s p
ot
Find
the
jum
per c
omin
g th
roug
h ho
le 1
8 th
at h
as c
ontin
uity
to
eyel
et 1
9 . S
olde
r th
is j
ump
er t
o th
e m
iddl
e lu
g of
the
vi
brat
o ch
anne
l bas
s po
t alo
ng w
ith th
e ju
mpe
r alre
ady
in p
lace
.
Find
the
jum
per c
omin
g th
roug
h ho
le 1
7 th
at h
as c
ontin
uity
to
eyel
et 3
6 . S
olde
r th
is ju
mpe
r to
the
left
lug
of th
e vi
brat
o ch
anne
l bas
s po
t alo
ng w
ith th
e re
sist
or
lead
alre
ady
in p
lace
.
Als
o so
lder
the
gree
n ju
mpe
r fro
m e
yele
t 6
to th
e ba
ck o
f the
vib
rato
cha
nnel
bas
s po
t .
S
TE
P 1
35
Sold
er t
he
reve
rb p
ot
Find
the
jum
per c
omin
g th
roug
h ho
le 1
3 th
at h
as c
ontin
uity
to
eyel
et 4
2 . S
olde
r th
is ju
mpe
r to
the
right
lug
of th
e re
verb
po
t .
Find
the
jum
per c
omin
g th
roug
h ho
le 1
3 th
at h
as c
ontin
uity
to
eyel
et 1
4 . S
olde
r th
is j
ump
er t
o th
e m
iddl
e lu
g of
the
re
verb
pot
.
Cut
a 1”
gre
en ju
mpe
r an
d re
mov
e th
e in
sula
tion .
Ben
d th
is ju
mpe
r in
a “J
” sha
pe
and
run
it fr
om th
e le
ft lu
g of
the
reve
rb
pot t
o th
e ba
ck o
f the
reve
rb p
ot . S
olde
r it
in b
oth
plac
es .
stew
mac
.com
4
6
©20
19 S
tew
Mac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4A
BC
D
FE
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
4 3
21
87
65
4 3
21
87
65
4 3
21
87
65
3MRA
50KRA
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
stew
mac
.com
4
7
©20
19 S
tew
Mac
S
TE
P 1
36
Sold
er t
he
spee
d p
ot
Find
the
jum
per c
omin
g th
roug
h ho
le 3
3 th
at h
as c
ontin
uity
to
eyel
et 6
8 . S
olde
r th
is ju
mpe
r to
the
right
lug
of th
e sp
eed
pot .
Sold
er th
e 6 .
8K re
sist
or le
ad in
the
cent
er
and
left
lugs
of t
he sp
eed
pot i
f you
hav
e no
t don
e so
.
S
TE
P 1
37
Sold
er t
he
inte
nsi
ty p
ot
One
of t
he w
ires
com
ing
thro
ugh
hole
9
will
hav
e co
ntin
uity
to e
yele
t 32
and
one
of t
hem
will
hav
e co
ntin
uity
to
eyel
et
8 . F
ind
thes
e tw
o w
ires
and
twis
t th
em
toge
ther
.
Find
the
jum
per c
omin
g th
roug
h ho
le 9
th
at h
as c
ontin
uity
to
eyel
et 3
2 . S
olde
r th
is ju
mpe
r to
the
right
lug
of th
e in
tens
ity
pot .
Find
the
jum
per c
omin
g th
roug
h ho
le 9
th
at h
as co
ntin
uity
to e
yele
t 8 . S
olde
r thi
s ju
mpe
r to
the
mid
dle
lug
of th
e in
tens
ity
pot .
Cut
a 1”
gre
en ju
mpe
r an
d re
mov
e th
e in
sula
tion .
Ben
d th
is ju
mpe
r in
a “J
” sha
pe
and
run
it fr
om th
e le
ft lu
g of
the
inte
nsity
po
t to
the
back
of t
he in
tens
ity p
ot . S
olde
r it
in b
oth
plac
es .
S
TE
P 1
38
Sold
er t
wo
tra
nsf
orm
er le
ads
Fin
d t
he
red
lea
d f
rom
th
e o
utp
ut
tran
sfo
rmer
co
min
g t
hro
ug
h t
he
gro
mm
eted
ho
le b
etw
een
th
e 6V
6 tu
bes .
Trim
it t
o an
app
ropr
iate
leng
th
and
sold
er it
to e
yele
t 46 .
Find
the
red
lead
from
the
reve
rb d
river
co
min
g th
roug
h th
e gr
omm
eted
hol
e be
twee
n tu
be so
cket
V3
and
tube
sock
et
V4 . T
rim it
to a
n ap
prop
riate
leng
th a
nd
sold
er it
to e
yele
t 88 .
S
TE
P 1
39
Sold
er b
ias
bo
ard
jum
per
sSo
lder
the
gree
n ju
mpe
r fro
m e
yele
t E o
f th
e bi
as b
oard
to
the
near
by t
hree
-lug
grou
ndin
g st
rip .
Sold
er th
e re
d/bl
ue le
ad fr
om th
e po
wer
tr
ansf
orm
er to
eye
let A
of t
he b
ias b
oard
.
Sold
er th
e ju
mpe
r fro
m h
ole
D to
the
right
lu
g of
the
bias
pot
.
Find
the
jum
per c
omin
g th
roug
h ho
le 9
th
at h
as c
ontin
uity
to
eyel
et 1
0 . S
olde
r th
is ju
mpe
r to
eyel
et C
of t
he b
ias b
oard
.
S
TE
P 14
0
Sold
er b
ias
po
t ju
mp
ers
Sold
er th
e ju
mpe
r fro
m h
ole
D to
the
right
lu
g of
the
bias
pot
.
Sold
er t
he ju
mpe
r fr
om h
ole
30 t
o th
e m
iddl
e lu
g of
the
bias
pot
.
S
TE
P 14
1
Ad
d t
wo
res
isto
rsTw
ist
the
lead
s of
tw
o 10
0Ω r
esis
tors
to
geth
er a
nd a
pply
sol
der t
o ke
ep th
em
join
ed . W
rap
the
two
resis
tors
’ oth
er le
ads
onto
the
pilo
t la
mp
lugs
alo
ng w
ith th
e gr
een
pow
er t
rans
form
er le
ads .
Do
not
sold
er th
ese
yet .
Sold
er t
he t
wis
ted
lead
s to
eye
let
E on
th
e bi
as b
oard
.
S
TE
P 14
2
Sold
er t
wo
filt
er c
ho
ke le
ads
Find
the
two
blac
k le
ads c
omin
g th
roug
h th
e g
rom
met
ed h
ole
bet
wee
n t
ube
sock
ets
V7 a
nd V
8 .
Sold
er o
ne o
f the
se le
ads
to e
yele
t 29 .
Sold
er th
e ot
her l
ead
to e
yele
t 64 .
S
TE
P 14
3
Inst
all t
wo
gre
en ju
mp
ers
Cu
t tw
o 15
-1/2
” g
reen
jum
per
s an
d tw
ist t
hem
toge
ther
, lea
ving
one
inch
of
untw
iste
d w
ire o
n ea
ch s
ide .
Wra
p th
e tw
o w
ires
from
one
sid
e of
thi
s tw
iste
d pa
ir th
roug
h th
e tw
o lu
gs o
f th
e pi
lot
lam
p as
sem
bly .
Sol
der
thes
e le
ads
into
pl
ace
with
the
two
100Ω
resi
stor
s and
the
gree
n po
wer
tran
sfor
mer
lead
s .
Rout
e th
ese
twis
ted
jum
pers
aro
und
the
edge
of
the
chas
sis
to r
each
soc
ket
V8,
but l
eave
room
for t
he c
hass
is m
ount
ing
scre
ws
to m
ake
it th
roug
h th
eir
hole
s .
Thes
e ar
e th
e tw
o ho
les v
ery
clos
e to
the
left
wal
l of t
he in
side
of t
he c
hass
is .
stew
mac
.com
4
8
©20
19 S
tew
Mac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4A
BC
D
FE
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
4 3
21
87
65
4 3
21
87
65
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
4 3
21
87
65
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
Step
147
: Tw
ist p
ins
4+5
toge
ther
on th
ese
sock
ets.
stew
mac
.com
4
9
©20
19 S
tew
Mac
Inst
all t
he
hea
ter
wir
esRe
view
thes
e st
eps
very
car
eful
ly b
efor
e yo
u st
art i
nsta
lling
the
heat
er w
ires
that
po
wer
the
heat
ing
filam
ents
in th
e tu
bes .
The
twis
ted
gree
n w
ires
from
the
pow
er
tran
sfor
mer
car
ry A
C vo
ltage
to th
e he
at-
ing
filam
ents
in th
e tu
bes .
It’s
impo
rtan
t to
twis
t the
se w
ires t
ight
ly to
geth
er . T
his
isn’
t fo
r lo
oks;
tw
istin
g th
e w
ires
has
a hu
m-c
ance
lling
fun
ctio
n th
at r
educ
es
nois
e in
the
amp .
S
TE
P 14
4
Co
nn
ect
to t
ub
e so
cket
V8
Cut
two
6" h
eate
r w
ires,
one
whi
te a
nd
one
bla
ck . T
wis
t th
em t
oget
her
very
ti
ghtl
y, l
eavi
ng a
bou
t 1"
of
the
ends
un
twis
ted
. Joi
n th
e w
hite
jum
per
to
eith
er o
f the
gre
en ju
mpe
rs b
y tw
istin
g th
e en
ds to
geth
er . J
oin
the
blac
k ju
mpe
r to
the
othe
r gre
en ju
mpe
r .
Sold
er th
e pa
ir w
ith th
e w
hite
wire
to p
in
2 of
soc
ket V
8 .
Sold
er th
e pa
ir w
ith th
e bl
ack
wire
to p
in
7 of
soc
ket V
8 . B
end
thes
e w
ires
up a
nd
away
from
the
sock
et .
At 1
" ab
ove
the
sock
et, b
end
the
blac
k-an
d-w
hite
pai
r at
a 9
0° a
ngle
tow
ard
sock
et V
7 .
S
TE
P 14
5
Co
nn
ect
to t
ub
e so
cket
V7
Cut
two
6" h
eate
r w
ires,
one
whi
te a
nd
one
blac
k . T
wis
t the
m ti
ghtly
toge
ther
.
Twis
t th
e en
d of
the
whi
te w
ire t
o th
e w
hite
jum
per c
omin
g fr
om V
8 . T
wis
t the
bl
ack
wire
with
the
blac
k ju
mpe
r com
ing
from
V8 .
Sold
er t
he w
hite
pai
r on
to p
in 2
of
V7 .
Sold
er t
he b
lack
pai
r on
to p
in 7
. Ben
d th
e w
ires
up a
way
from
the
sock
et, a
nd
on to
war
d so
cket
V6 .
Mak
e su
re t
hat
the
like-
colo
red
jum
per
wire
s ar
e go
ing
to t
he s
ame-
num
bere
d pi
ns, o
r you
will
hav
e a
phas
e is
sue
from
th
e pu
lsin
g vo
ltage
. For
exa
mpl
e, if
the
w
hite
wire
is s
olde
red
to s
ocke
t V8
pin
2 an
d th
e bl
ack
wire
is so
lder
ed in
to so
cket
V8
pin
7, m
ake
sure
you
conn
ect t
he w
hite
w
ire to
sock
et V
7 pi
n 2
and
the
blac
k w
ire
to s
ocke
t V7
pin
7 .
S
TE
P 14
6
Co
nn
ect
to t
ub
e so
cket
V6
On
sock
ets
V6 th
roug
h V1
you
will
nee
d to
join
pin
s 4
and
5 to
geth
er . O
n th
ese
six
sock
ets,
gen
tly tw
ist p
ins
4 an
d pi
n 5
tow
ard
each
oth
er so
thei
r eye
lets
line
up .
Be v
ery
care
ful w
hile
doi
ng th
is, a
s the
se
pins
are
del
icat
e .
Cut
two
4" h
eate
r w
ires,
one
whi
te a
nd
one
blac
k . T
wis
t the
m ti
ghtly
toge
ther
.
Twis
t the
end
of t
he w
hite
wire
toge
ther
w
ith
the
whi
te j
ump
er c
omin
g fr
om
sock
et V
7 . T
wis
t th
e bl
ack
wire
with
the
bl
ack
jum
per c
omin
g fr
om s
ocke
t V7 .
Sold
er th
e w
hite
pai
r to
sock
et V
6 pi
n 9
and
sold
er t
he b
lack
pai
r to
com
bine
d pi
ns 4
+5 o
n so
cket
V6 .
Ben
d th
e w
ires
up a
way
from
the
sock
et, a
nd o
n to
war
d so
cket
V5 .
S
TE
P 14
7
Co
nn
ect
to t
ub
e so
cket
V5
Cut
two
4" h
eate
r w
ires,
one
whi
te a
nd
one
blac
k . T
wis
t the
m ti
ghtly
toge
ther
.
Twis
t th
e lik
e-co
lore
d w
ires
of t
his
new
pa
ir in
with
the
like-
colo
red
wire
s of
the
twis
ted
pair
com
ing
from
soc
ket V
6 .
Sold
er th
e pa
ir of
twis
ted
whi
te w
ires
to
sock
et V
5 pi
n 9
and
sold
er t
he t
wis
ted
blac
k w
ires
to s
ocke
t V5
pin
4+5
. Ben
d th
e w
ires
up a
way
from
the
sock
et, a
nd
on to
war
d so
cket
V4 .
S
TE
P 14
8
Co
nn
ect
to t
ub
e so
cket
V4
Cut
two
5" h
eate
r w
ires,
one
whi
te a
nd
one
blac
k . T
wis
t the
m ti
ghtly
toge
ther
.
Twis
t th
e lik
e-co
lore
d w
ires
of t
his
new
pa
ir in
with
the
like-
colo
red
wire
s of
the
twis
ted
pair
com
ing
from
soc
ket V
5 .
Sold
er th
e pa
ir of
twis
ted
whi
te w
ires
to
sock
et V
4 pi
n 9
and
sold
er t
he t
wis
ted
blac
k w
ires
to s
ocke
t V4
pin
4+5
. Ben
d th
e w
ires
up a
way
from
the
sock
et, a
nd
on to
war
d so
cket
V3 .
Minimi
ze hum
from
AC vo
ltage b
y twis
ting
heater
wires
tightly
tog
ether
and ro
uting
them u
p abov
e the
signal
-carry
ing wi
res.
stew
mac
.com
5
0
©20
19 S
tew
Mac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4A
BC
D
FE
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
4 3
21
87
65
4 3
21
87
65
4 3
21
87
65
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
stew
mac
.com
5
1
©20
19 S
tew
Mac
S
TE
P 14
9
Co
nn
ect
to t
ub
e so
cket
V3
Cut
two
4" h
eate
r w
ires,
one
whi
te a
nd
one
blac
k . T
wis
t the
m ti
ghtly
toge
ther
.
Twis
t th
e lik
e-co
lore
d w
ires
of t
his
new
pa
ir in
with
the
like-
colo
red
wire
s of
the
twis
ted
pair
com
ing
from
soc
ket V
4 .
Sold
er th
e pa
ir of
twis
ted
whi
te w
ires
to
sock
et V
3 pi
n 9
and
sold
er t
he t
wis
ted
blac
k w
ires
to s
ocke
t V3
pin
4+5
. Ben
d th
e w
ires
up a
way
from
the
sock
et, a
nd
on to
war
d so
cket
V2 .
S
TE
P 1
50
Co
nn
ect
to t
ub
e so
cket
V2
Cut
two
4" h
eate
r w
ires,
one
whi
te a
nd
one
blac
k . T
wis
t the
m ti
ghtly
toge
ther
.
Twis
t th
e lik
e-co
lore
d w
ires
of t
his
new
pa
ir in
with
the
like-
colo
red
wire
s of
the
twis
ted
pair
com
ing
from
soc
ket V
3 .
Sold
er th
e pa
ir of
twis
ted
whi
te w
ires
to
sock
et V
2 pi
n 9
and
sold
er t
he t
wis
ted
blac
k w
ires
to s
ocke
t V2
pin
4+5 .
S
TE
P 1
51
Co
nn
ect
to t
ub
e so
cket
V1
Run
the
blac
k-an
d-w
hite
tw
iste
d pa
ir up
1" f
rom
the
tube
soc
ket,
dire
ctly
ove
r to
soc
ket
V1, a
nd b
ack
dow
n so
cket
V1 .
So
lder
the
whi
te w
ire t
o so
cket
V1
pin
9 an
d so
lder
the
blac
k w
ire to
soc
ket V
1 pi
n 4+
5 .
Care
fully
insp
ect
each
sol
der
join
t fr
om
this
hea
ter
wire
inst
alla
tion,
and
onc
e th
e so
lder
join
ts h
ave
cool
ed p
ush
your
he
ater
wire
s aw
ay fr
om th
e tu
be so
cket
s as
far a
s yo
u ca
n .
S
TE
P 1
52
Ad
d t
he
po
wer
co
rd +
str
ain
rel
ief
Strip
the
pow
er c
ord’
s ou
ter
insu
latio
n b
ack
unti
l th
e b
lack
-and
-whi
te l
eads
ca
n re
ach
from
the
acc
ess
hole
to
the
pow
er s
witc
h an
d fu
se . T
wis
t th
e bl
ack-
and-
whi
te le
ads
toge
ther
. Cut
the
gree
n le
ad f
rom
the
pow
er c
ord
to r
each
the
th
ree-
lug
grou
ndin
g st
rip
jus
t in
side
th
e ch
assi
s un
dern
eath
the
hol
e fo
r th
e po
wer
cord
. Tin
this
gre
en le
ad a
nd w
rap
it th
roug
h th
e m
iddl
e lu
g of
the
thre
e-lu
g gr
ound
ing
strip
.
Pull
the
pow
er c
ord
lead
s th
roug
h th
e ho
le in
the
cha
ssis
and
sec
ure
with
the
bl
ack
stra
in re
lief .
The
stra
in re
lief i
s a ti
ght fi
t . U
se p
liers
to
sque
eze
it on
to th
e po
wer
cor
d ou
tsid
e th
e ch
assi
s, a
nd k
eep
sque
ezin
g to
fit
it in
to th
e m
ount
hol
e .
S
TE
P 1
53
Co
nn
ect
the
po
wer
co
rd le
ads
Run
the
twis
ted
blac
k an
d w
hite
pow
er
cord
wire
s al
ong
the
back
wal
l of
the
chas
sis .
Sold
er th
e po
wer
cord
’s w
hite
wire
to th
e rig
ht lu
g on
the
pow
er s
witc
h .
Sold
er t
he p
ower
cor
d’s
blac
k w
ire t
o th
e ce
nter
/bac
k lu
g of
the
fus
e so
cket
. D
ange
r: So
lder
ing
this
lead
to
the
side
lu
g of
the
fuse
soc
ket w
ill c
reat
e a
shoc
k ha
zard
.
Sold
er t
he p
ower
cor
d’s
gree
n gr
ound
w
ire o
nto
the
near
by g
roun
ding
str
ip .
Take
a b
reak
an
d r
evie
w y
ou
r w
ork
Now
that
you’
ve so
lder
ed th
e com
pone
nts
and
wire
s, it
’s tim
e to
take
a b
reak
. Res
t yo
ur e
yes
and
revi
ew y
our
wor
k la
ter,
care
fully
loo
king
aga
in f
or a
ny e
rror
s be
fore
mov
ing
on .
stewmac.com 52 © 2019 StewMac
STEP 154
Install the fuseInsert the 1-amp fuse into the fuse socket and make sure the socket cap is secure . Never use a fuse rated above 1 amp in this amplifier .
STEP 155
Install the capacitor panUse the self-tapping screws to mount the capacitor pan on the chassis, covering the filter cap board .
Installing parts and preparing for testing
STOP!
DON’T INSTALL THE TUBES YET! DON’T PLUG THE AMP IN YET!
The next page is going to keep you out of trouble!
STEP 158
Set the chassis on a chassis stand or on blocks for testingSet your chassis up for final testing . Chassis stands are extremely useful for this . If you do not have a chassis stand a couple of blocks of wood can work just fine .
STEP 156
Install the pilot lampInsert the pilot lamp bulb into its socket from the front of the chassis and twist until it locks back in place . Screw the red jewel lens over the socket .
STEP 157
Install the control knobsTurn the shaft of each pot to “zero” and install the knob so that the indicator line points to number 1 .
stewmac.com 53 © 2019 StewMac
STEP 161
Test the dangerous DC voltageThe dangerously high DC voltage that passes through the rectifier tube and the filter caps is referred to as “B+” . The next step is to test this B+ voltage .
With the amp still unplugged and turned off, install the 5AR4 rectifier tube while spreading the tension clip .
Plug the power cord back in and turn the power switch to ON . The pilot lamp should light, along with the filament inside the 5AR4 rectifier tube .
Again, spend a few minutes watching for smoke or smells before flipping the standby switch to ON .
For safety, use only one hand to probe the amp during DC tests. Keep your other hand behind your back when probing a component, so you can’t be a path between B+ voltage and ground—a mistake that would send a dangerous charge through your heart .
Set your multimeter to 600V DC and connect the negative lead to ground . Once the negative lead is secured to ground, flip the standby switch to ON . Measure the DC voltage at eyelet 46 for your B+ voltage . This should be roughly 490V DC .
Turn the power and standby switches to OFF and unplug the amp .
Any multimeter will work fine for the two types of tests we’re about to do: checking continuity and reading voltages . The instructions that came with your meter will be helpful .
Continuity testing is simply making sure current f lows between two points successfully . Touch the meter's red lead to one end of the section being tested, and the black lead to the other end . If the continuity is good, your meter will beep or register this on the display .
Voltage testing is where you need to be careful . Some steps require the amp to be plugged in and turned on . This becomes dangerous if you’re not cautious . Respect the voltages and follow the directions, and these tests are safe and easy .
STEP 159
Perform a safe power-upAt this point, there should be no tubes installed, and the speaker should be disconnected .
Before plugging the amp in, turn the power switch to ON . Switching the amp on before the first power-up protects you from shock if a mistake in your wiring has created a short to the chassis . If this short exists, an indication would be that the pilot light will not turn on, since the AC current is going directly to ground .
Plug the power cord in . The pilot lamp should light .
For a few minutes, watch for smoke or unusual smells . If anything seems unusual, disconnect the power immediately and carefully review all your connections .
STEP 160
Test the standard AC voltageSet your multimeter to 20V AC . Check the heater voltage across pin 9 and pins 4+5 on the V1 12AX7 socket . This should read between 5-7V AC . If this reading is drastically different, disconnect power and check your connections .
If the amp seems normal, unplug the power cord and turn the power switch OFF .
Testing and troubleshooting
V1
6
4 32
1
987
5
D
F
43 8
7
65
43 8
7
65
38
28
1 2 3
76
29
M
46
6465
75
104J
60
0VALWAYS discharge the filter cap
before working on the circuit. See how
to use a snuffer stick on page 6.
And seriously, keep one hand behind
your back!
stewmac.com 54 © 2019 StewMac
STEP 162
Test the preamp tubesWith the amp unplugged use the snuffer stick to discharge the capaci-tors, then install the six preamp tubes .
After these tubes are installed, plug the amp back in and flip the power switch ON . The pilot lamp should light up . Let the amp warm up for a few minutes and then flip the standby switch to ON . Again, if you get smoke or smells, unplug immediately .
Connect your multimeter’s negative lead to ground .
Set the multimeter to 5V DC and check eyelet 96, which should read around 1 .3V .
Set the multimeter to 200V DC and check eyelet 98 . It should read around 200V .
Set the multimeter to 100V DC and test pin 5 of the V7 and V8 sockets . These readings should be nearly identical .
Use a small flathead screwdriver to turn the center of the bias pot all the way counter-clockwise . This will set the bias for the lowest negative DC voltage . Doing this provides a safe voltage for the power tubes while you set the initial bias .
If all of these voltages come within approximately 10% of their expected values, turn the power switch OFF . Always turn the power switch off before turning the standby switch off . This will drain the filter capacitors as the amp cools down . After a moment, flip the standby switch OFF as well .
If the reading at eyelet 98 shows no voltage or low voltage, follow this test: unplug the amp, drain the filter caps with the snuffer stick, set your meter to read continuity, and make sure you have properly installed the back-of-board jumper from eyelet 35 to eyelet 62 .
STEP 163
Test the 6V6 power tubesWith the amp unplugged, install the 6V6 power tubes, turning them so their indexing keys fit correctly in the socket . Turn all of the front panel con-trols completely counter-clockwise, so the indicator line is pointing to "1" .
Plug the speaker in and perform these next tests with the speaker turned away from you . If the amp starts to oscillate and squeal, this will help protect your ears .
Plug the amp in and flip the power switch ON . Give the tubes 30 seconds to warm up and then flip the standby switch to ON as well .
After a few moments you should hear a low hum . If the hum becomes very loud, disconnect the power immedi-ately and review your connections .
Set your multimeter to read 500V DC and test for voltage on pin 3 of both socket V7 and socket V8 . This is the plate voltage reading, and it will be around 415V . Write this number in Box 2 of the calculation in Step 167 . It’ll be needed if you use a bias meter to set your bias .
Set your multimeter to read 50V DC and test for voltage at eyelet 39 . Adjust the bias pot until this voltage reads -35V .
If all of these voltages come within approximately 10% of their expected values, turn the power switch OFF . After a few moments turn the stand-by switch OFF as well, and unplug the amp .
Tube bias affects your sound“Bias” refers to the current of elec-trons flowing from the cathode to the plate inside your power tubes when the tubes are idle . The bias setting determines this flow and is increased or decreased by the screwdriver-ad-justable bias pot .
Adjusting the bias affects your sound: a higher setting gives you punchier cleans and grittier distortion, but your tubes will wear out faster . With a low setting, your tubes last longer but the sound is more sterile . A good bias setting falls between these extremes .
Testing and troubleshooting
stewmac.com 55 © 2019 StewMac
STEP 164
Old method of setting the bias: doing it by earIf you have a bias meter, skip this step and go on to Step 165 .
The old-school way of adjusting the bias is by ear: after setting the bias voltage to a recommended starting point, you make tiny adjustments to the bias pot while listening for the sound you want . This inexact method can shorten the life of your power tubes .
You roughed-in the bias setting in the previous step by setting the bias voltage at -35V .
Danger: set your guitar aside before you adjust the bias pot. Do not touch any amp circuitry while holding your guitar . Doing so would create an electricution hazard!
Use a screwdriver to make a tiny adjustment to the bias pot . Turn clockwise to increase the current and counter-clockwise to decrease it . Then set the screwdriver aside and play to hear to the result .
Watch out for red-platingYou especially want to avoid too much current turning the gray plates to glowing red . If your tubes start red plating, shut the amp down and let it cool before setting the bias to a lower level .
STEP 165
Improved method of setting the bias: using a bias meterThe more accurate way to set the bias is by using a bias meter, such as the VHT Bias Tester (StewMac #1580) .
This method starts with a simple cal-culation to find your bias setting, then you adjust the bias pot until your bias meter displays that reading .
The calculation uses two numbers, the tube’s maximum plate dissipation and its plate voltage .
Plate dissipation. Every power tube has a specified plate dissipation—the maximum wattage the tube can handle . For the 6V6 power tubes in this amp, that maximum is 14 watts . Exceeding the 14-watt limit will dam-age the tube, and operating at the full 14 watts will shorten its life . Our goal is to operate the tube at 60% of the 14-watt limit, or 8 .4 watts . We've entered this number for you in Box 1 of the calculation .
Plate voltage. You already have the plate voltage for these tubes: it’s the the number you found in Step 163 and wrote in Box 2 below .
Divide Box 1 by Box 2. The result is your recommended bias setting for use in the next step . Our example cal-culation gives a bias recommendation of .020 Amps . Since bias is typically measured in milliamps, this measure-ment is written as 20mA .
Calculate your bias current setting
Example:
Your plate voltage from Step 16560% of max. plate dissapation
÷Your bias current setting
=8.4
BOX 2BOX 1
8.4 ÷ =
With the amp unplugged allow the power tubes to cool . Once the power tubes have cooled, remove them from their sockets .
Plug the tubes in to the bias probe sockets, which are like tube sockets . Plug the probe sockets with tubes into the power tube sockets .
Plug the amp back in and flip the power switch ON . Give the tubes 30-60 seconds to warm up, then flip the standby switch ON .
Watch the bias meter as the power tubes heat up . Both needles should rise at an equal rate and settle at the same time .
Adjust your bias pot until the bias meter displays the reading you calcu-lated (20mA in our example) . Let the amp idle for a few minutes to make sure that the bias doesn’t drift .
When you see a constant readout of your bias setting, turn the power switch OFF .
After a few moments flip the standby switch OFF and unplug the amp from the wall .
Once the tubes are cool, remove them and the bias probes from the amp and plug the tubes back in to the amp's tube sockets without the probes attached .
stewmac.com 56 © 2019 StewMac
After playing for a few minutes and testing all inputs, if everything seems to be operating normally, go ahead and turn the amp off . Install the chassis into the cabinet, install the power cord clamp in the side wall of the cabinet, install the preamp tube shields, and install the back panels .
STEP 166
Test the reverb and tremoloConnect the two shielded cables you assembled in Step 7 to the reverb in and out jacks on the back of the chassis . Connect the chassis out cable to the reverb tank’s in jack . Connect the chassis’s in cable to the out jack on the reverb tank . Also connect the footswitch cables to the reverb and vibrato jacks .
Plug the amp back in and flip the power switch ON . Allow the tubes to warm up for 30 seconds, then flip the standby switch ON .
Plug your guitar into the normal channel and play at low volume . If the amp behaves as it should, test the tone controls and keep increasing the volume . The 66D should start to break up nicely as you increase the volume .
Now test the vibrato channel effects . If the reverb isn’t working, try switch-ing the cables in the reverb in and out jacks . If that doesn’t remedy the issue, check your reverb cables again for a short .
If there are any strange oscillations, squeals, or the amp seems at all unsta-ble, use a wooden chopstick to begin probing for loose connections: n from the input jacks to the eyelet boardn from the tube sockets to the eyelet boardn from the tube sockets to the front panel controls . It usually takes just a minor wiring ad-justment, perhaps resoldering a loose joint, to correct this sort of distortion .
Final assembly
STEP 167
Install the chassisDischarge the capacitors so you can safely handle the amplifier . Remove all the cables from their jacks .
Slide the chassis in from the back until its front edge rests on the speaker baffle . Align the chassis straps with the holes in the top of the cabinet . Insert the mounting screws through the straps and down through the chassis . Tighten the locknuts .
Install the preamp tube shields . Fas- ten the power cord to the cable clamp on the side of the cabinet and install the back panels .
Slide the reverb tank into its bag and lay it on the floor of the cabinet . The RCA connections inside the bag should be facing front, toward the speaker baffle .
Plug in the speaker, footswitch, and reverb tank .
It's finally time to let it rip!
GO!GO!
stewmac.com 57 © 2019 StewMac
Tube lifeThe life span of the power tubes is affected by how hard you drive the amp . If you are overdriving the amp for hours every day, expect the power tubes to have a shorter life span .
We encourage you to experiment with different tube brands and find the brand that is most favorable to your ears and your wallet .
For questions and support, StewMac is here to help!For more than fifty years, StewMac has supplied instrument builders and repair shops . Our customer service team really knows how to help if you run into questions .
Call 800-848-2273 from 9AM–6PM Eastern time, Monday–Friday . Email: service@stewmac .com
Thanks for choosing this StewMac ICON KIT, and welcome to the world of amp building!
Tips for using the 66D
Enjoy your amp!For many players, this is a “desert island” amp: the one to choose if you could only have one amplifier .
It has very little hum for a vintage circuit, the reverb is cavernous, and the distortion is just right . Also, the tremolo doesn’t make the unwanted ticking noise you find with some vin-tage tremolos . (Speaking of tremolo, Leo mistakenly named this effect “vi-brato,” but let’s forgive him for that .) .
Why is this amp so sweet, and how do you dial it in? The AB763 tone stack has a distinct mid scoop: the bass and treble controls boost their ranges while leaving the mids unaffected . With bass and treble set to minimum, the tone stack bleeds off about 25dB from the signal . For this reason, try setting the bass and treble at about 6 . If you’re using single-coils, maybe bump the bass up a bit more, and give humbuckers a little more treble .
The normal channel doesn’t have reverb and tremolo . This unaffected channel is helpful if you have a reverb pedal on your board and don't want to send your signal through a reverb tank . However, most players seem to prefer the vibrato channel .
With the bass and treble at about 6, try the reverb control between 4 and 5 .
You can vary the tremolo speed and intensity settings quite a lot depend-ing on the song, but the tremolo can become overwhelming when the intensity goes past 6 .
I usually play with the volume control on my guitar at 10, and the 66D sits right on the edge of distortion with the volume around 5 .5-6 . Increasing the volume past that point doesn't make the amp louder, but the tubes start to saturate and the tone goes into full-on gorgeous, harmonic distortion .
There’s no right or wrong way to play this amp, and it’s almost impossible to pull a sour tone from it!
Matt Clouston, StewMac
stewmac.com 58 © 2019 StewMac
OutputGain
Negative feedback
Processing
Power
Mic level
Speaker levelLine level Line level
You don’t need to read a schematic to build this kit . But it’s fun to see how the circuit works, and to see the different subcircuits that interact to shape your sound .
Working with the tiny signal from the guitar, the amp creates the power needed to drive the speaker . The signal is affected by the gain, processing, output and power stages as it passes through the circuit .
The gain circuit increases the signal strength to line level (about 1 volt), by passing it through preamp tubes .
Inside the tube, electrons flow from a heated cathode to be received by the anode plate . Between these is a grid receiving the tiny voltage from the guitar . The guitar’s varying musical signal controls the flow of electrons to the plate .
V1 handles the first gain stages of the normal channel, and V2 handles the first gain stages of the vibrato chan-nel . The vibrato channel has an extra gain stage in the second half of V4 to make up for signal lost through the reverb and vibrato circuits .
The negative feedback loop flattens and extends the amp’s frequency re-sponse, reducing distortion generat-ed in the output stage . This makes the amp’s sound cleaner and more hi-fi .
Some players disable this loop com-pletely or add a potentiometer in place of the resistor to create a “grit control .” We don’t recommend this, because it places stress on the output transformer .
The processing stage shapes the tone . The AB763 is notorious for its mid-scooping tone stack .
Both the normal channel and the vibrato channel have processing con-trols through their respective treble and bass controls, and the vibrato channel has additional processing through the reverb and vibrato cir-cuits .
V3 handles the reverb send and the first half of V4 handles the reverb re-covery . V5 handles the vibrato circuit .
Both channels are then sent to the phase inverter which uses all of V6 . The phase inverter then sends the signal to the output section .
The power supply stage provides power to the other circuit stages, as well as the tube heaters and pilot light .
This circuit receives the AC power from your wall and passes it through the power transformer to create higher voltage . The electricity then goes to the rectifier, which converts it to a pulsing DC current .
This then passes through the filter choke and the filter cap board . The filter cap board contains five capacitors that filter out the pulsing to create a smooth current . As each cap smoothes a bit more, the current is also passing through resistors that lower the voltage .
As the signal from the guitar becomes more amplified, the ripple of DC current becomes less evident and the fully filtered current is sent to the most sensitive part of the amplifier, the first pre-amp tube in the Gain stage .
The output stage increases the line level signal to speaker level, which is typically 8 volts or greater .
Two 6V6 tubes drive the output trans-former . They receive the split signal, 180 degrees out of phase, amplify those signals, and send them to the output transformer to be recombined into one signal . This transformer adjusts the impedance to 8 ohms to drive the amp’s 8Ω speaker .
This amp has an adjustable fixed bias, which means you need to check the bias and possibly make adjustments when you change power tubes .
cathode
plate
grid
We’ve color-coded these stages on our schematic, to show how the parts work together . Symbols for components are in the key at the bottom of the frame .
On the wiring diagram we build step-by-step in these pages, the parts are easier to recognize . But studying these color-coded stages will help you understand where each component fits into the creation of your sound .
Learning more: secrets revealed in the schematic
stewmac.com 59 © 2019 StewMac
#10
737
©
20
19 S
tew
Ma
c
Gro
und
Jack
Tran
sfor
mer
Prea
mp
tub
e pla
tegr
id
cath
ode
Pow
er tu
be
grid
pla
te
cath
ode
scre
en
Cap
acito
r
Elec
trol
ytic
Cap
.
Dio
deRe
sist
orPo
tent
iom
eter
sRe
ctifi
er tu
be
Op
tois
olat
or
pla
teca
thod
e
filam
ent
pla
te
Shie
lded
cab
le
’66
D-R
EV
ER
B 22
WO
RIG
INA
L A
B76
3 C
IRC
UIT
Gai
nG
ain
Proc
essi
ng
Proc
essi
ng
Proc
essi
ng
Out
put
PowerN
egat
ive
Feed
bac
k
68K
25μF50V
25μF50V
25μF50V
1.5K
6.8K
68K
B
BD
2
2
6 +18
0V
6+
180 V
+1.
3V 8
+1.
3 V 8
8 +1.
3V
+20
0V 1
+77
V
250p
F
10pF
.1pF
.01μF
.047
μF
.022
μF
.003
3μF
.01μ
F
AE
E
C
BC
VIB
RA
TOP
EDA
L
REV
ERB
PED
AL
REV
ERB
UN
ITO
utp
utIn
put
.1μF
.001
μF
.1μF
.1μ
F
SOC
KET
V1
70
25
SOC
KET
V4
70
25
NORMAL
SOC
KET
V3
12
AT
7
SOC
KET
V9
GZ
34
SOC
KET
V5
12
AX
7
SOC
KET
V6
12
AT
7
SOC
KET
V7
6V6
GT
SOC
KET
V8
6V6
GT
.1μF
500p
F
.047
μF1
100K
100K
100K
100Ω
100Ω
82K
220K220K
220K
47Ω
1M1M
100K
3.3M220K
22K
1.5K
470Ω
820Ω
470Ω
470Ω
1.5K
10K
10K
100K
220K
100K
100K
100K
100K
100K
470K
220K
2.2M
220K
10M
10K
470Ω
250KATREBLE
1MAVOLUME
250KABASS
3MR
ASP
EED
50KRAINTENSITY
68K
25μF50V
1.5K
25μF50V
820Ω
6.8K
68K
1M1M
2
2
+17
0V 1
+18
0V 1
3 +
1.3 V
3 +
1.3V
+17
0V 6
+18
0V 6
250p
F47
pF
A
.1μF
SOC
KET
V2
70
25
VIBRATO
.047
μF1
100K
250KATREBLE
100KLREVERB
1MAVOLUME
250KABASS
7EX
TEN
SIO
NSP
EAK
ER
TR3
TR2
STA
ND
BY
SWIT
CH
TR4
TR1
TR1:
125
P33A
12
5P23
B TR
2: 1
25C
3ATR
3: 1
25A
1ATR
4: 1
25A
20B
8 8
5
68
42
3 +
1.2V
+17
0 V 11
22
+41
0 V6
8 +
8.7V
3 +
370V
3 +
415V
-35V
+415V
2.2K
1M
330V
AC
AC
sw
itch
1 am
psl
ow-b
low
fuse
To tu
be
heat
ers
and
pilo
t lig
ht
330V
AC
820Ω
25μF50V
16μF450V
16μF450V
25μF50V
27K
25μF50V
100AK
.02μF
16μF
450V
16μF
450V
D16
μF
450V
1M 1M10
KL2
1 3
6
7
8
7
72
8
5
4 +
365V
4 +
415V
stewmac.com 60 © 2019 StewMac
It’s your amp. Your tone. You built it!
’57 MINI TWEED 5W AMP KITOne-knob titan of tone.A timeless studio darling whose tiny size hides tremendous punch and versatility .
The 5F1 circuit was meant to be a student amp but wasn’t kid stuff for long; rock’s finest guitarists hijacked it for some of the greatest songs ever recorded . Listen to Eric Clapton (“Layla") or Joe Walsh (“Rocky Mountain Way") while you build this amp!
Our simplest kit; the quickest way to get into amp building .
#10730 5 WATTS / 8" SPEAKER / ORIGINAL 5F1 CIRCUIT
’65 P-REVERB 15W AMP KITSparkling bright, perfect for the surf.Plug your single-coils straight in for that signature clean American tone, or go surfing with onboard effects .
The smallest member of the black-panel family to offer reverb and tremolo, this amp made its name as a jangly pop dream machine . Aficionados treasure its early low-end breakup powered by a pair of 6V6 tubes .
Listen to “Surfin’ USA" and the great sounds of Ryan Adams .
#10734 15 WATTS / 10" SPEAKER / ORIGINAL AA1164 CIRCUIT
’66 D-REVERB 22W AMP KITFamously clean, with enough guts to gig.Perfect for recording as well as performing, the D-Reverb produces stinging clarity that absolutely refuses to get lost in the mix .
One of the most popular designs ever, this amp lives in the happy middle between bright clarity and rich distortion . It excels in the studio and on the stage . While capable of crystal clear tones at good volume, you can push this one into beautifully saturated, play-sensitive distortion .
It’s all here: clarity, distortion, and rectifier tube sag .
#10737 22 WATTS / 12" SPEAKER / ORIGINAL AB763 CIRCUIT
H OU RS : 6
D I F F I C U LTY
H OU RS : 1 2
D I F F I C U LTY
H OU RS : 8
D I F F I C U LTY
H OU RS : 16
D I F F I C U LTY
’59 TWEED 15W AMP KITDirty little devil that shaped guitar history.With mysteriously fat saturated tone, this little monster makes it easy to achieve seismic distortion .
This amp’s 5E3 circuit is an enigma: Why do the controls on the channel you’re NOT using make your tone so great? The answer: Who cares? This is one of the greatest tone monsters ever created! Listen to Neil Young’s Rust Never Sleeps while building this kit .
Our most popular amp kit and a great learning experience .
#10731 15 WATTS / 12" SPEAKER / ORIGINAL 5E3 CIRCUIT
StewMac ICON KITS teach you the world of amp building, then turn you loose with amazing hand-built tone machines!
stewmac.com 61 © 2019 StewMac
’62 BRIT-PLEX 45W AMP KITThe original British showstopper.This amp started a revolution . It’s been rocking the world for over 50 years, and we still can’t get enough .
Favored by blues and rock players for exceptional sustain and rich creamy tone, the ’62 Brit-Plex is chock-full of harmonic gain, yet it still stays articulate and even a little crispy . Put this head on a classic 4x10 cab and watch out!
While building, listen to Gary Moore’s “Still Got The Blues ."
#10736 45 WATTS / ORIGINAL BRITISH CIRCUIT
’66 BRIT-74X 18W AMP KITLeave your half-stack at home.Born in London, this little blues blaster earns its living every night, gigging in clubs across the USA .
Launched in 1966, this amp quickly became a low-wattage holy grail . This is a stripped-down blues machine: two channels, one tone knob, no master volume . Buckle up and go where this gritty beast takes you! It comes with a footswitch to kick in the onboard tremolo .
Get the plexi tone without blowing the roof off the joint!
#10732 18 WATTS / 12" SPEAKER / ORIGINAL BRITISH CIRCUIT
’81 BRIT-800 50W AMP KITThis hairy monster lives to shred.The defining British circuit that dominated the ’80s .
This 50W giant created your favorite heavy rock and metal albums . Used by Slayer and Pixies, and recorded on early Metallica albums, this circuit produces that screaming guitar tone that your mother despises . With solid-state rectification there’s no sag, and the distortion created by this circuit is way more about treble than mids or bass .
Listen while building: Smashing Pumpkins’ Siamese Dream .
#10735 50 WATTS / ORIGINAL BRITISH CIRCUIT
’64 REVERB UNIT KITReverb you can’t get from a pedal.This is the unit that put the waves in surf music! Looks like an amp, sounds like a beach party .
This tube-driven reverb tank relies on good ol’ physics for a perfect effect . Your guitar signal travels along two large suspended springs to produce the reverb that launched the iconic surf sound . This isn't a pocket-sized digital simulation; this is the real deal!
Listen to Dick Dale’s “Misirlou" while doing this easy build .
#10733 ORIGINAL 6G15 CIRCUIT
H OU RS : 1 2
D I F F I C U LTY
H OU RS : 1 2
D I F F I C U LTY
H OU RS : 16
D I F F I C U LTY
H OU RS : 8
D I F F I C U LTY
Beginner-tested. Pro quality.StewMac ICON KITS are fun to build, with friendly instructions to guide you and loads of info to add to your knowledge.
stewmac.com 62 © 2019 StewMac
NO
RMA
LV
OLU
ME
TREB
LEB
ASS
VO
LUM
ETR
EBLE
BA
SSRE
VER
BPI
LOT
SPEE
DIN
TEN
SITY
VIB
RAT
O
21
21
REV
ERB
INPU
TRE
VER
B
OU
TPU
TRE
VER
B
PED
AL
VIB
RAT
OPE
DA
LEX
T. S
PKR
SPEA
KER
STA
ND
BYPO
WER
FUSE
GRO
UN
D
V1
12A
X7
V2
12A
X7
V3
12A
T7V
412
AX
7V
512
AX
7V
612
AT7
V7
6V6
V8
6V6
V9
5AR4A
BC
D
FE
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
6
4321
98 7 5
4 3
21
87
65
4 3
21
87
65
4 3
21
87
65
250KA
1MA
1MA
1MA
250KA
250KA
100KL
3MRA
50KRA
250KA
250KA
382812
34
56
78
5152
10 34 54 68 8385
8687
9091
9294
9796
95
584349
503231
93614435 60
986362
45
3611
37
5541
1214
15
8856
89
42
1619
2123
26 9976
7778
8182
7980
29
46 64
39 4748
30
6566
67
53339
846970
71
72
59
57
7374
40
1320
2227
1817
2524
75
47
+
25µ
F
104J 600V
104J 600V
473J 600V
473J 600V
+25µF
+25µF
473J 600V
250
222J 600V
332J 600V
+25µF
510+
+25µF
+25µF
102J 1119
10pF
+25µF
+25µF
104J 600V
104J 600V
.01μF .01μF .02μF
104J 600V
104J 600V
250
’66
D-R
ev
erb
22W
OR
IGIN
AL
AB
763
CIR
CU
IT#
1073
7
©2
019
Ste
wM
ac
stewmac.com 63 © 2019 StewMac
’66 D-Reverb 22WO R I G I N A L A B 7 6 3 C I R C U I T
StewMac®
I C O N K I T S
Use only 1-amp slow-blow fuse, size 5mm x 20mm.
DANGER: Unplug the amp before changing tubes.Tube locations from left to right:
12AX7(ECC83)
12AX7(ECC83)
V5 V4
6V6 12AT7(ECC81)
V7 V6
12AX7(ECC83)
12AX7(ECC83)
V2 V1
12AT7(ECC81)
V3
5AR4(GZ34)
6V6
V9 V8
#10737
’66 D-Reverb 22WO R I G I N A L A B 7 6 3 C I R C U I T
StewMac®
I C O N K I T S
Use only 1-amp slow-blow fuse, size 5mm x 20mm.
DANGER: Unplug the amp before changing tubes.Tube locations from left to right:
12AX7(ECC83)
12AX7(ECC83)
V5 V4
6V6 12AT7(ECC81)
V7 V6
12AX7(ECC83)
12AX7(ECC83)
V2 V1
12AT7(ECC81)
V3
5AR4(GZ34)
6V6
V9 V8
#10737
Cut this label on the dotted line with a razor knife and metal straightedge .Fasten it inside the cabinet using thinned wood glue or contact cement .
The duplicate copy below is included as a backup .
stewmac.com 64 © 2019 StewMac
stewmac.com 65 © 2019 StewMac
tools + ideas for guitarmakingStewMac
21 N . Shafer St ., Athens, OH 45701800-848-2273 stewmac .com
©2019 StewMac . All rights reserved .#10737 Updated February, 2019