Post on 14-Jan-2022
A S S E M B LY I N S T R U C T I O N SWith loads of helpful tips!
’65 P-REVERB 15W C O M B O A M P K I T ORIGINAL AA1164 CIRCUIT
Sparkling bright,perfect for the surf.
stewmac.com 2 © 2018 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
Wrapping parts onto the bias board . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Wrapping parts onto the main board . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Installing and soldering the boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Installing the fuse, lamp, and knobs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Testing and troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Final assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Tips for using this amp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Learning more: secrets revealed in the schematic . . . . . . . . . . . . . . 46
AA1164 circuit schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
More iconic amp kits from StewMac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
AA1164 wiring diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Tube replacement chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
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 © 2018 StewMac
Iconic American tone is now in your hands
Be excited!Your new StewMac ’65 P-Reverb will be a blast to play through and even more fun to build .
Plug your single-coils straight in and use its signature clean tone, or go surfing with the onboard effects .
This amp is an ICONThe smallest member of the black-panel family to offer both 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 power tubes .
Suggested listening while you build this kit: the Beach Boys’ “Surfin’ USA” and the great sounds of Ryan Adams .
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 P-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!
’65 P-REVERB 15W CO MB O AMP KIT ORIGINAL AA1164 CIRCUIT
stewmac.com 2 © 2018 StewMac
Here’s how to build this amp!
See page 20
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 46.
Sort your components by type, using the parts list.Quick look:
#10734 © 2018 StewMac
’65 P-REVERB 15WORIGINAL AA1164 CIRCUIT
GroundJackTransformer Preamp tube
plategrid
cathode
Power tube
grid
plate
cathode
screen
Capacitor Electrolytic Cap. DiodeResistor Potentiometers Rectifier tube
plate cathodefilamentplate
Shieldedcable
Gain GainGainProcessing Processing
ProcessingProcessing
Output
Power
Processing
Negative Feedback
68K
250K
A25
0KA
25μF
50V
25μF
50V
25μF
50V
25μF
50V
1.5K
100K68
K
1M
40μF
500V
20μF
500V
20μF
500V
20μF
500V
BB
D B
.1μF
22K 100μF
100V
2
2
1+160V
+160V
6
3+1.3V
8+1.3V
+160V
6
8+1.2V
+200V
6
8+50V
7
25μF
50V
25μF
50V
1.5K 1.
5K
100K
250pF
+240V +240V
100K
3MRASpeed
+320V
Vibratopedal
Reverbpedal
Reve
rb10
0KL
Reverb unitOutputInput
15K-2W 15K-2W
1K-1W
.1μF.022μF .022μF
SOCKET V1
7025
SOCKET V2
12AT7
SOCKET V7
GZ34
SOCKET V6
6V6 GT
SOCKET V4
12AX7
SOCKET V5
6V6 GTSOCKET V3
12AX7.1μF
.1μF
.01μF
500pF
3.3M
2700
10pF
.047μF
1
100K
TREB
LE
VOLU
ME
BASS
6.8 K
1MA
77
5 ExtensionSpeaker
TR2
TR3
TR1
TR1: 125P1BTR2: 125A10B TR3: 125A20B
8
8
5
6 8
4 2
3 +2.4V
23
3 +1.2V
+160V1
2
1
72
4+400V
+400V 6
8+8.0V
+400V4
3 +410V
3 +410V
+49V
100K
47Ω
56K
1K
-34V
220K +
420V
220K
1M
1M
1M 220K
2.2K1M
100K
470K
.033
μF
+42
0V
.02μ
F
.02μ
F
.01μ
F
56K
1M
+260V +250KLIntensity
100K
340VACAC switch
1 ampslow-blow fuse
To tube heaters and pilot light
340VAC
3.3K
220K
1.5K
OutputGain Processing
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A magnifierhelps!
Capacitors and diode
r (1) 250pF 500V silver mica
r (1) 500pF 500V silver mica
r (1) .0033μF 600V Orange Drop
r (3) .022μF 600V Orange Drop
r (2) .047μF 600V Orange Drop
r (4) .1μF 600V Orange Drop
r (1) 10pF 500V ceramic disk
r (2) .01μF 500V ceramic disk
r (1) .02μF 500V ceramic disk
r (6) 25μF 50V Sprague Atom
r (1) 100μF 100V aluminum electrolytic
r (1) 40μF/20μF/20μF/20μF 500V filter cap
r (1) 1N4007 1000V rectifier diode
510K
332J 600V
223J 600V
473J 600V
104J 600V
+
25µF
100μf
500V
Resistors
r (1) 47Ω .5W carbon composite
r (2) 100Ω .5W carbon composite
r (1) 1K .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 (1) 3.3K .5W carbon composite
r (1) 6.8K .5W carbon composite
r (1) 22K .5W carbon composite
r (2) 56K .5W carbon composite
r (2) 68K .5W carbon composite
r (7) 100K .5W carbon composite
r (4) 220K .5W carbon composite
r (1) 470K .5W carbon composite
r (6) 1M .5W carbon composite
r (1) 3.3M .5W carbon composite
r (1) 1K 2W metal oxide
r (2) 15K 2W metal oxide
Yellow Violet Black Gold
Brown Black Brown Gold
Brown Black Red Gold
Brown Green Red Gold
Red Red Red Gold
Red Violet Red Gold
Orange Orange Red Gold
Blue Gray Red Gold
Red Red Orange Gold
Green Blue Orange Gold
Blue Gray Orange Gold
Brown Black Yellow Gold
Red Red Yellow Gold
Yellow Violet Yellow Gold
Brown Black Green Gold
Orange Orange Green Gold
Brown Black Red Gold
Brown Green Orange Gold
Hardware
r (6) 8-32 machine screw, 3/8"r (10) 8-32 locknut
r (6) 6-32 machine screw, 1/2"r (6) 6-32 locknut
r (6) 4-40 machine screw, 3/8"r (8) 4-40 machine screw, 1/4"r (14) 4-40 locknut
r (2) Chassis mounting strapr (4) Chassis strap screw and nut
r (6) Rubber grommet
r (1) Strain relief for power cord
r (1) Filter cap mounting clamp
r (1) Cabinet
r (1) 10” speaker
r (1) Chassis
r (1) Cable clamp
r (1) Screw for cable clamp
r (1) Faceplate/backplate set
r (2) Eyelet boards set
r (2) Insulator boards set
103K
203Z
Parts list
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r (1) Speaker plug
r (4) RCA-style jack
r (3) Three-lug shorting jack
r (1) Two-lug mono jack
r (4) Nine-pin tube socket
r (4) Shield for nine-pin socket
r (3) Eight-pin tube socket
r (3) Tension clip for 8-pin socket
r (3) 12AX7 preamp tube (also called ECC83S)
r (1) 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)
Transformers
r (1) Power transformer
r (1) Output transformer
r (1) Reverb driver
4
3 2
18
76
5
12AT712A
X7
6V6
5AR
4
6
4 3 21
987
5
r (2) 250K control pot (A–audio taper)
r (1) 1M control pot (A–audio taper)
r (1) 3M control pot (RA–reverse audio taper)
r (1) 100K control pot (L–linear taper)
r (1) 250K control pot (L–linear taper)
r (6) Knob
r (2) Three-lug terminal strip
r (1) Power switch (2 lugs)
r (1) Ground switch (3 lugs)
r (1) Power cord
Reverb
r (1) Reverb tank
r (1) Reverb tank bag
r (1) Reverb wiring kit
r (1) Reverb footswitch
Wire
r (1) White wire
r (1) Green wire
r (1) Speaker wire (two leads)
1234
10
56
7 8 9
250KA
1MA
3MRA
100KL
250KL
Parts list
Vintage-style push-back wire lets you push the insulation back instead of cutting it away. BUT: Trimming the insulation still works better.
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#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" 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
Copper shielding tape Item #0028 2" Conductive Copper Tape
Pencil Colored art markers Wooden chopsticks Glue Wood glue, white glue or contact cement for gluing a paper label inside the cabinet
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
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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
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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 8μF and 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
8μf
How to read resistor values Capacitor values
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STEP 3
Solder the speaker leadsTwist the speaker leads together to keep them neat .
Push the insulation back 3/8" and in-sert the white lead into the speaker’s positive terminal and the black lead into the negative terminal .
Before soldering these leads, place a business card or other protection under the terminals to prevent sol-der dripping onto the speaker cone . Solder the two leads to the speaker terminals .
Prepare the cabinet for mounting the amp chassis by first removing the two back panels .
STEP 1
Mount the power cord clampDrill a 5/64" pilot hole to mount the nylon cable clamp . Locate the clamp inside the left wall of the cabinet, 8" up from the bottom and 1" in from the panel mounting ledge .
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 cable clamp screw to mount the clamp . You’ll secure the power cord with this clamp later, after the testing .
Start by prepping the cabinet
Check off eachcompleted step
STEP 2
Solder the speaker plugUse a small screwdriver to remove the back 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 con-tinuity test with your multimeter to make sure there’s no connection between the plug’s tip and its metal case (see page 43) .
Back
Here
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’65 P-REVERB 15WO R I G I N A L AA1 1 64 C I R C U I T
StewMac®
I C O N K I T S
Use only 1-amp slow-blow fuse.
DANGER: Unplug the amp before changing tubes.Tube locations from left to right:
5AR4(GZ34)
6V6 6V612AT7(ECC81)
12AX7(ECC83)
V7 V6 V5 V2 V1
12AX7(ECC83)
12AX7(ECC83)
V4 V3
#10734
STEP 7
Solder four RCA plugsThe 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 jumper . 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 5
Install the faceplate + backplateSecure the faceplate by putting the 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 2-lug extension speaker jack and the 3-lug ground switch .
This switch is just for looks, because ground switches are not needed in modern amps with 3-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 chart
Cut out the tube replacement chart on page 51 . Put a thin coat of glue or contact cement on the back and glue it to the inside wall of the cabinet .
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 mounting nuts so they lightly touch 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 damage the cone and cause un-wanted distortion .
Criss-cross tightening prevents warping.
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This circuit is built on two eyelet boards: the large main board and a smaller one called the bias board . For each of these, there’s an additional blank insulator board of the same size .
These insulators mount behind the eyelet boards to prevent the com-ponents from contacting the metal chassis .
Each pair of boards will mount to the chassis with two machine screws . The first step in preparing these boards is to drill mounting holes through the blank insulators .
Prepping the eyelet boards
STEP 8
Drill the insulator boardsNoting the eyelet holes, orient the boards as shown above . Align each eyelet board with its insulator and tape them together .
The mounting holes are pre-drilled in the main eyelet board, but not in its insulator board . Drill through the holes indicated using a 5/32" drill bit . Separate the boards and set the insulator board aside for later .
The smaller bias board does not have pre-drilled mounting holes . Place it in the chassis as shown . Holding the board in position, turn the chassis over to see the mounting holes .
With a sharp pencil, mark the two hole locations onto the insulator board . Drill two 5/32" mounting holes through this pair of boards . Set the insulator board aside for later .
You'll drill the mounting holes in the bias board. In the main board, they're already drilled.Insulator
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STEP 9
Number the eyelets and holesThese instructions will refer to the eyelets and holes on the main eyelet board by number and the bias board by letter . Use a pencil to mark these numbers and letters onto the boards .
STEP 10
Prep one grounding stripWith a wire cutter, snip the mounting holes on a 3-lug terminal strips as pictured . Cut a 1" piece of green wire and remove the insulation . Wrap and solder the wire across the terminals, electrically connecting all three lugs . This will be used as a grounding strip .
Snip
Wrap
Solder
1 53 4
2
10
59
20176 7 8 9 11
5857565554
60 61 62 63 64 6568 69 70
71
72
73
7466 67
1213
14 15 1618 19 21
2425 26
273029
28 31
22 2332 33 34 35
37 40 41 42
43 4445 46 47 48 49 50
51 525338
39
36
A B CD
EF
Tips for great soldering!n Wrap the leads tightly for a good electrical contact before soldering . Don’t use solder to “glue” loose joints .
n Melt a small amount of solder onto the tip of the iron (“tinning” the iron) . Hold the tip against the connection until the connection reaches solder-ing temperature . This should take just a few seconds .
Also tin component leads like multi-strand wires to help the solder flow for a better joint .
n Keep your soldering tip clean by wiping it often on a damp sponge . And keep it tinned by occasionally melting a little solder onto it .
n Feed solder to the connection, not to the iron . Stop feeding solder once an eyelet is filled . Keep the iron on the connection 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 After the joint has cooled, trim away the excess wires .
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 .
You’re ready to build!
stew
mac
.co
m
12
©20
18 S
tew
Mac
VIB
RAT
OPE
DA
LRE
VER
BPE
DA
LRE
VER
BO
UTP
UT
REV
ERB
INPU
TSP
EAK
ERPO
WER
GRO
UN
DFU
SEEX
TEN
SIO
N
PILO
TLA
MP
V7
5AR4
V6
6V6
V5
6V6
V4
12A
X7
V3
12A
X7
V2
12AT
7V
112
AX
7
INTE
NSI
TYSP
EED
REV
ERB
BA
SSTR
EBLE
VO
LUM
EIN
STRU
MEN
TS
21
POW
ERTR
AN
SFO
RMER
FILT
ER C
AP
OUTPUT TRANSFORMER(mounted outside)
REVERB DRIVER(mounted outside)
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
O
–
U
X
Y
250KA
1MA
stew
mac
.co
m
13
©20
18 S
tew
Mac
Inst
alli
ng
th
e ch
assi
s-m
ou
nte
d c
om
po
nen
ts
S
TE
P 1
1
Mo
un
t th
e p
ow
er t
ran
sfo
rmer
an
d t
wo
3-l
ug
ter
min
al s
trip
sTh
e p
ower
tra
nsfo
rmer
has
nin
e le
ads
colo
r-co
ded
in fo
ur p
airs
, plu
s a si
ngle
red/
yello
w s
trip
ed le
ad . T
wis
t the
sam
e-co
lor
pai
rs to
geth
er . F
eed
all t
he le
ads
into
the
chas
sis
thro
ugh
the
squa
re h
ole .
Inst
all
the
tran
sfo
rmer
on
th
e o
uts
ide
of t
he c
hass
is, u
sing
fou
r 8-
32 lo
cknu
ts
insi
de .
Mo
un
t th
e tw
o t
erm
inal
str
ips
und
er th
e lo
cknu
ts a
t the
fron
t and
bac
k co
rner
s as
sho
wn:
the
one
you’
ve tu
rned
in
to a
gro
undi
ng s
trip
goe
s to
the
fron
t .
S
TE
P 1
2
Inst
all t
hre
e ru
bb
er g
rom
met
sSq
uee
ze t
hes
e in
to t
he
thre
e h
ole
s as
sh
own .
The
se g
rom
met
s p
rovi
de
stra
in
relie
f fo
r th
e tr
ansf
orm
er w
ires
that
will
p
ass
thro
ugh
the
met
al c
hass
is .
S
TE
P 1
3
Mo
un
t th
e o
utp
ut
tran
sfo
rmer
The
ou
tpu
t tr
ansf
orm
er h
as r
ed, b
lue,
br
own,
bla
ck, a
nd g
reen
lead
s . T
hrea
d th
e re
d, b
lue
and
bro
wn
lead
s th
roug
h th
e le
ft r
ubb
er g
rom
met
as
pic
ture
d in
the
di
agra
m, a
nd t
he b
lack
and
gre
en le
ads
thro
ugh
the
mid
dle
grom
met
.
Usi
ng
tw
o 8
-32
mac
hin
e sc
rew
s an
d lo
cknu
ts, m
ount
the
tra
nsfo
rmer
to
the
outs
ide
of th
e ch
assi
s .
S
TE
P 14
Mo
un
t th
e re
verb
dri
ver
The
reve
rb d
rive
r is
a t
rans
form
er w
ith
red,
blu
e, g
reen
, and
bla
ck le
ads .
Thr
ead
thes
e fo
ur le
ads
thro
ugh
the
rem
aini
ng
rub
ber
gro
mm
et .
Use
tw
o 8-
32 x
1/4
" m
achi
ne s
crew
s to
m
ount
the
rev
erb
driv
er o
n th
e ou
tsid
e of
the
chas
sis .
S
TE
P 1
5
Mo
un
t th
e fi
lter
cap
acit
or
The
larg
e fil
ter c
ap m
ount
s to
the
chas
sis
with
the
filte
r cap
acito
r mou
ntin
g cl
amp .
Th
e cl
amp
att
ache
s to
the
end
of c
apac
i-to
r nea
r the
lugs
, and
then
mou
nts t
o th
e ch
assi
s us
ing
6-32
x 1
/2" m
achi
ne s
crew
s an
d lo
cknu
t . If
need
ed, e
nlar
ge th
e sc
rew
ho
les
by d
rillin
g th
em w
ith a
5/3
2" b
it .
Att
ach
the
clam
p s
o th
at t
he c
apac
itor’s
ne
gativ
e lu
g (m
arke
d “–
”) is
clo
sest
to th
e p
ower
tran
sfor
mer
, as
show
n .
S
TE
P 1
6
Inst
all t
he
spea
ker
ou
tpu
t ja
ckA
dd
the
3-lu
g sp
eake
r ou
tput
jack
nex
t to
the
2-lu
g ex
tens
ion
spea
ker j
ack
whi
ch
you’
ve a
lread
y in
stal
led
.
Thes
e ja
cks
are
elec
tric
ally
gro
un
ded
th
roug
h co
ntac
t w
ith t
he m
etal
cha
ssis
, so
tigh
ten
them
wel
l for
a g
ood
grou
nd .
S
TE
P 1
7
Inst
all t
he
thre
e la
rge
tub
e so
cket
s w
ith
ten
sio
n c
lip
sO
rient
the
se 8
-pin
tub
e so
cket
s so
tha
t p
in 1
is c
lose
st t
o th
e re
ar p
anel
of
the
chas
sis .
Use
4-4
0 x
3/8"
mac
hine
scre
ws t
o m
ount
th
ese
sock
ets
on th
e ou
tsid
e of
the
chas
-si
s . In
clud
e a
tens
ion
clip
on
top
of e
ach
sock
et to
pro
vide
sup
por
t for
thes
e th
ree
tub
es w
hen
they
’re in
stal
led
late
r .
S
TE
P 1
8
Inst
all t
he
fou
r sm
all t
ub
e so
cket
sU
se t
wo
4-40
x 1
/4"
mac
hine
scr
ews
to
mou
nt th
e fo
ur re
mai
ning
tub
e so
cket
s .
Posi
tion
thes
e so
cket
s so
pin
3 is
clo
sest
to
the
rear
pan
el o
f the
cha
ssis
.
S
TE
P 19
Inst
all t
he
fuse
so
cket
Mo
un
t th
e fu
se s
ock
et s
o i
ts s
ide
lug
face
s th
e op
en s
ide
of t
he c
hass
is . T
his
orie
ntat
ion
mak
es it
eas
ier t
o so
lder
late
r .
S
TE
P 2
0
Inst
all t
he
po
wer
sw
itch
Mou
nt th
e p
ower
switc
h w
ith it
s tw
o lu
gs
faci
ng u
p fo
r sol
der
ing
late
r .
S
TE
P 2
1
Inst
all t
he
fou
r R
CA
jack
sM
ount
the
RC
A ja
cks
to t
he c
hass
is w
ith
the
larg
e w
ashe
rs o
n th
e ou
tsid
e . O
nce
in-
stal
led,
ben
d th
e gr
ound
ing
tab
s sl
ight
ly
away
from
the
insi
de
of th
e ch
assi
s .
S
TE
P 2
2
Inst
all t
he
pil
ot
lam
p s
ock
etM
ount
the
soc
ket
by s
crew
ing
the
lens
fr
om
th
e o
uts
ide
into
th
e so
cket
as-
sem
bly
. Pos
itio
n th
e so
cket
so
the
arm
su
pp
ortin
g th
e la
mp
fac
es t
he s
ide
wal
l of
the
chas
sis .
Som
e am
p b
uild
ers a
dd
a dr
op o
f glu
e to
th
e m
ount
ing
thre
ads
to k
eep
vib
ratio
ns
from
loos
enin
g th
e so
cket
from
hig
h-vo
l-um
e p
layi
ng .
stew
mac
.co
m
14
©20
18 S
tew
Mac
VIB
RAT
OPE
DA
LRE
VER
BPE
DA
LRE
VER
BO
UTP
UT
REV
ERB
INPU
TSP
EAK
ERPO
WER
GRO
UN
DFU
SEEX
TEN
SIO
N
PILO
TLA
MP
V7
5AR4
V6
6V6
V5
6V6
V4
12A
X7
V3
12A
X7
V2
12AT
7V
112
AX
7
INTE
NSI
TYSP
EED
REV
ERB
BA
SSTR
EBLE
VO
LUM
EIN
STRU
MEN
TS
21
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
OU
X
Y
O
–
U
X
Y
250KA
250KA
1MA
3MRA
100KL
250KL
stew
mac
.co
m
15
©20
18 S
tew
Mac
S
TE
P 2
3
Inst
all t
he
rem
ain
ing
co
ntr
ol p
ots
Mou
nt t
he c
ontr
ol p
ots
wit
h th
eir
lugs
fa
cing
up
for s
old
erin
g . W
hen
we
refe
r to
lugs
as
left
or
right
, it’s
ass
umin
g yo
u’re
lo
okin
g at
the
pot
fro
m t
he s
ame
poi
nt
of v
iew
as
in th
e w
iring
dia
gram
.
Mou
nt th
em a
s fo
llow
s:
Inte
nsit
y:
250K
L p
ot
Spee
d:
3MRA
pot
Re
verb
: 10
0KL
pot
Ba
ss:
250K
A p
ot
Treb
le:
250K
A p
ot
Volu
me:
1M
A p
ot
S
TE
P 2
4
Inst
all 1
00
K r
esis
tor
+ 6
.8K
res
isto
rRu
n o
ne
lead
of
the
100K
res
isto
r u
p
thro
ugh
the
bot
tom
of t
he le
ft lu
g of
the
spee
d p
ot a
nd w
rap
it d
own
thro
ugh
the
mid
dle
lug
of
the
sam
e p
ot . I
t d
oes
n’t
mat
ter w
hich
dire
ctio
n th
is re
sist
or is
in-
stal
led,
bec
ause
resi
stor
s are
n’t p
olar
ized
. So
lder
the
resi
stor
lead
to b
oth
lugs
.
Sold
er t
he o
ther
lead
of
this
res
isto
r to
th
e b
ack
of th
e sp
eed
pot
.
Wra
p on
e le
ad o
f the
6 .8
K re
sist
or th
roug
h th
e le
ft lu
g of
the
bas
s p
ot b
ut d
on’t
sol-
der
this
con
nect
ion
yet .
Sold
er th
e 6 .
8K re
sist
or’s
othe
r lea
d to
the
bac
k of
the
bas
s p
ot .
S
TE
P 2
5
Inst
all t
wo
jum
per
sCu
t tw
o w
hite
wire
s, 2
" lon
g . C
onne
ctin
g w
ires
like
this
are
cal
led
jum
per
s .
Wra
p o
ne e
nd o
f a ju
mp
er o
nto
the
mid
-dl
e lu
g of
the
bas
s pot
and
wra
p th
e ot
her
end
of th
is ju
mp
er o
nto
the
left
lug
of th
e tr
eble
pot
. Sol
der
the
con
nect
ion
to t
he
left
lug
of t
he t
reb
le p
ot, b
ut le
ave
the
mid
dle
lug
of t
he b
ass
pot
uns
old
ered
fo
r now
.
Wra
p o
ne e
nd o
f the
oth
er ju
mp
er o
nto
the
mid
dle
lug
of t
he t
reb
le p
ot . W
rap
th
e ot
her
end
onto
the
rig
ht lu
g of
the
vo
lum
e p
ot . S
old
er t
he c
onne
ctio
ns a
t b
oth
ends
of t
his
jum
per
.
S
TE
P 2
6
Inst
all t
wo
jack
s +
a 1
M r
esis
tor
Ad
d in
stru
men
t ja
cks
1 an
d 2
. Pos
itio
n th
em so
the
cent
er lu
g of
jack
2 is
clo
se to
th
e si
de
lug
of ja
ck 1
as
pic
ture
d .
Wra
p o
ne le
ad o
f a
1M r
esis
tor
thro
ugh
the
right
lug
of ja
ck 1
and
wra
p it
ont
o th
e ce
nter
lu
g o
f th
e sa
me
jack
. Mak
e su
re t
his
lead
won
’t b
e in
the
way
whe
n an
inst
rum
ent c
able
is p
lugg
ed in
.
Run
this
resi
stor
’s o
ther
lead
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 y
et .
S
TE
P 2
7
Inst
all t
wo
68
K r
esis
tors
Twis
t th
e le
ads
of t
he t
wo
68K
resi
stor
s to
geth
er, c
reat
ing
one
conn
ectio
n . W
rap
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
resi
tor l
ead
onto
the
left
lug
of ja
ck 1
, ad
ding
it to
the
conn
ec-
tion
mad
e in
the
pre
viou
s st
ep .
Sold
er a
ll th
ese
con
nec
tio
ns, a
nd
als
o so
lder
the
twis
ted
68K
resi
stor
lead
s .
S
TE
P 2
8
Po
wer
tra
nsf
orm
er b
lack
lead
sRu
n ei
ther
of
the
bla
ck w
ires
fro
m t
he
pow
er tr
ansf
orm
er to
the
sid
e 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 2
9
Po
wer
tra
nsf
orm
er g
reen
lead
sRu
n th
e tw
o gr
een
wire
s fr
om th
e p
ower
tr
ansf
orm
er to
the
lugs
on
the
pilo
t lam
p
sock
et (e
ither
wire
can
go
to e
ither
lug)
. Tr
im t
hes
e w
ires
to
len
gth
an
d w
rap
th
em o
nto
the
lugs
. Don
’t so
lder
the
se
conn
ectio
ns y
et .
Despite
being
green
, these
aren’
t gro
und wi
res. Th
ey pow
er the
pilot
lamp a
nd tub
e heat
er fila
ments
.
stew
mac
.co
m
16
©20
18 S
tew
Mac
VIB
RAT
OPE
DA
LRE
VER
BPE
DA
LRE
VER
BO
UTP
UT
REV
ERB
INPU
TSP
EAK
ERPO
WER
GRO
UN
DFU
SEEX
TEN
SIO
N
PILO
TLA
MP
V7
5AR4
V6
6V6
V5
6V6
V4
12A
X7
V3
12A
X7
V2
12AT
7V
112
AX
7
INTE
NSI
TYSP
EED
REV
ERB
BA
SSTR
EBLE
VO
LUM
EIN
STRU
MEN
TS
21
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
OU
X
Y
O
–
U
X
Y
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
Enla
rged
tosh
ow d
etai
l
stew
mac
.co
m
17
©20
18 S
tew
Mac
S
TE
P 3
0
Po
wer
tra
nsf
orm
er r
ed/y
ello
w le
adTr
im th
e p
ower
tran
sfor
mer
’s re
d/y
ello
w
lead
to a
n ap
pro
pria
te le
ngth
and
sol
der
it
to th
e fr
ont g
roun
ding
str
ip a
s sh
own .
S
TE
P 3
1
Po
wer
tra
nsf
orm
er r
ed le
ads
Trim
the
pow
er tr
ansf
orm
er’s
red
lead
s to
an a
pp
rop
riate
leng
th a
nd w
rap
one
lead
on
to p
in 4
of t
he V
7 tu
be
sock
et (5
AR4
) . So
cket
pin
s hav
e up
per
and
low
er e
yele
ts
for m
ultip
le c
onne
ctio
ns .
Wra
p t
he
oth
er r
ed l
ead
ont
o p
in 6
of
the
sam
e so
cket
. Don
’t so
lder
the
se r
ed
lead
s ye
t .
S
TE
P 3
2
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
pro
pri
ate
leng
th . W
rap
one
of
thes
e le
ads
onto
pin
2 o
f soc
ket V
7 .
Wra
p t
he o
ther
yel
low
lea
d o
nto
pin
8
of t
he s
ame
sock
et . D
on’t
sold
er t
hese
ye
llow
lead
s ye
t .
S
TE
P 3
3
Ou
tpu
t tr
ansf
orm
er
blu
e an
d b
row
n le
ads
Trim
the
blu
e w
ire fr
om th
e ou
tput
tran
s-fo
rmer
to a
n ap
prop
riate
leng
th a
nd w
rap
it
onto
pin
3 o
f soc
ket V
5 . D
on’t
sold
er th
is
conn
ectio
n ye
t .
Trim
th
e b
row
n w
ire
fro
m t
he
ou
tpu
t tr
ansf
orm
er t
o a
n a
pp
rop
riat
e le
ng
th
and
wra
p it
ont
o p
in 3
of s
ocke
t V6 .
Don
’t so
lder
this
con
nect
ion
yet .
Leav
e th
e re
d o
utp
ut t
rans
form
er l
ead
free
for n
ow, y
ou’ll
con
nect
it la
ter,
whe
n th
e ey
elet
boa
rd is
inst
alle
d .
S
TE
P 3
4
Two
jum
per
sA
dd
a 1-
1/2"
whi
te ju
mp
er b
etw
een
the
right
lug
of th
e sp
eake
r jac
k an
d th
e rig
ht
lug
of
the
exte
nsi
on
jac
k . W
rap
th
ese
join
ts, b
ut d
o no
t sol
der
them
yet
.
Cut a
3/4
" whi
te ju
mp
er a
nd re
mov
e th
e in
sula
tion .
Ad
d th
is s
hort
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
bot
h en
ds .
S
TE
P 3
5
Ou
tpu
t tr
ansf
orm
er g
reen
an
d
bla
ck le
ads
Trim
thes
e tw
o w
ires t
o re
ach
the
spea
ker
jack
and
ext
ensi
on s
pea
ker j
ack .
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
fr
om th
e p
revi
ous
step
.
Sold
er th
e b
lack
lead
to th
e le
ft lu
g of
the
exte
nsio
n sp
eake
r jac
k .
S
TE
P 3
6
Co
nn
ect
the
reve
rb d
rive
r le
ads
Trim
the
gre
en le
ad to
rea
ch t
he m
iddl
e lu
g o
f th
e re
verb
inp
ut j
ack,
tin
it
and
sold
er it
to th
e lu
g .
Trim
the
bla
ck le
ad t
o re
ach
the
grou
nd
tab
on
the
reve
rb in
put
jack
. Tin
it a
nd
sold
er it
to th
is ta
b .
Trim
the
blu
e le
ad to
reac
h p
in 6
of s
ocke
t V2
. Tin
it a
nd w
rap
it o
nto
the
pin
, but
d
on’t
sold
er it
yet
.
Leav
e th
e re
d l
ead
fre
e fo
r n
ow, y
ou’ll
co
nnec
t it t
o th
e ey
elet
boa
rd la
ter o
n .
S
TE
P 3
7
Ad
d t
hre
e w
hit
e ju
mp
ers
Cut t
wo
3/4"
whi
te ju
mp
ers .
Wra
p o
ne o
f th
em b
etw
een
pin
2 a
nd p
in 7
of s
ocke
t V2
. Sol
der
the
conn
ectio
n to
pin
2 .
Wra
p th
e se
cond
sho
rt ju
mp
er b
etw
een
pin
3 a
nd p
in 8
of s
ocke
t V2
. Sol
der
the
co
nnec
tion
to p
in 3
.
Cut a
2" w
hite
jum
per
and
con
nect
it b
e-tw
een
pin
s 1
and
6 on
soc
ket
V2 . R
oute
th
is j
ump
er i
n a
sem
icir
cle
arou
nd
th
e so
cket
. Sol
der
thi
s ju
mp
er a
t p
in 1
and
al
so a
t p
in 6
whe
re it
join
s th
e b
lue
wire
fr
om th
e re
verb
driv
er .
For ne
at loo
king w
iring, u
se wir
e str
ippers
to tri
m 1/4"
of the
insula
tion
from t
he end
s of th
e push
-back
wire.
stew
mac
.co
m
18
©20
18 S
tew
Mac
VIB
RAT
OPE
DA
LRE
VER
BPE
DA
LRE
VER
BO
UTP
UT
REV
ERB
INPU
TSP
EAK
ERPO
WER
GRO
UN
DFU
SEEX
TEN
SIO
N
PILO
TLA
MP
V7
5AR4
V6
6V6
V5
6V6
V4
12A
X7
V3
12A
X7
V2
12AT
7V
112
AX
7
INTE
NSI
TYSP
EED
REV
ERB
BA
SSTR
EBLE
VO
LUM
EIN
STRU
MEN
TS
21
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
4 3
21
87
65
O
–
U
X
Y
6
4321
98 7 5
stew
mac
.co
m
19
©20
18 S
tew
Mac
S
TE
P 3
8
Ad
d t
hre
e m
ore
jum
per
sCu
t on
e 3"
gre
en ju
mp
er . W
rap
one
end
on
to p
in 8
of
sock
et V
5 an
d so
lder
thi
s co
nnec
tion .
Trim
aw
ay a
ny e
xces
s w
ire .
Wra
p t
he o
ther
end
of t
his
jum
per
ont
o p
in 8
of s
ocke
t V6 .
Cu
t o
ne
5" g
reen
ju
mp
er .
Sold
er o
ne
end
to
pin
8 o
f so
cket
V6
alo
ng
wit
h th
e ju
mp
er c
omin
g fr
om V
5 . S
old
er t
he
othe
r en
d of
thi
s 8"
jum
per
to
the
fron
t gr
ound
ing
strip
.
Cut o
ne 4
" whi
te ju
mp
er . S
old
er o
ne e
nd
to p
in 4
of s
ocke
t V6,
and
sold
er th
e ot
her
end
the
pin
4 o
f soc
ket V
5 .
S
TE
P 3
9
Two
wh
ite
jum
per
s +
on
e re
sist
or
Cut
one
1-1/
4" w
hite
jum
per
. Sol
der
one
en
d o
nto
the
mid
dle
lug
of
the
reve
rb
outp
ut ja
ck .
Wra
p th
e ot
her e
nd o
nto
the
mid
dle
lug
of th
e re
verb
ped
al ja
ck . D
on’t
sold
er th
is
join
t yet
.
Wra
p a
220
K r
esis
tor
on
to t
he
mid
dle
lug
of
the
reve
rb p
edal
ja
ck . S
old
er t
his
resi
stor
’s o
ther
le
ad t
o t
he
gro
un
d t
ab o
f th
e re
verb
out
put
jack
.
Cut a
1-1
/2" w
hite
jum
per
. Wra
p o
ne e
nd
onto
the
mid
dle
lug
of t
he r
ever
b p
edal
ja
ck a
nd w
rap
the
oth
er e
nd o
nto
pin
2
of s
ocke
t V3
. Sol
der
thi
s ju
mp
er a
t b
oth
ends
.
S
TE
P 4
0
On
e g
reen
jum
per
+ t
hre
e re
sist
ors
Cut
on
e 2"
gre
en j
ump
er . I
nsta
ll it
be-
twee
n fi
lter
cap
’s n
egat
ive
(–)
lug
an
d th
e ne
arb
y gr
ound
ing
stri
p . S
old
er t
he
conn
ectio
ns a
t bot
h en
ds .
Wra
p a
15K
2W re
sist
or b
etw
een
filte
r cap
lu
gs “O
" and
“U
" . D
on’t
sold
er it
yet
.
Twis
t th
e le
ads
of
two
100
Ω r
esis
tors
to
geth
er a
nd a
pp
ly s
old
er to
kee
p th
em
join
ed . W
rap
the
two
resi
stor
s’ o
ther
lead
s on
to t
he p
ilot
lam
p lu
gs a
long
with
the
gr
een
pow
er t
rans
form
er le
ads .
Do
not
sold
er th
ese
yet .
S
TE
P 4
1
Ad
d o
ne
gre
en ju
mp
erCu
t one
4" g
reen
jum
per
. Sol
der
one
end
to
th
e tw
iste
d c
om
bin
ed l
ead
s o
f th
e 10
0Ω re
sist
ors
you
just
con
nect
ed to
the
pilo
t lam
p so
cket
. Sol
der t
he o
ther
end
of
this
jum
per
to th
e fr
ont g
roun
ding
str
ip .
Sto
p a
nd
insp
ect
you
r w
ork
This
is a
goo
d tim
e to
ste
p a
way
from
the
pro
ject
for
a f
ew m
inut
es . T
ake
a b
reak
b
efor
e re
view
ing
your
wor
k fo
r err
ors .
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’v
e m
ade
so f
ar . W
hen
eve
ryth
ing
chec
ks o
ut, y
ou’re
rea
dy
to m
ove
on t
o th
e ey
elet
boa
rd .
Be sus
piciou
s Ass
ume t
here's
a m
istake
and
you’re
the on
e wh
o’ll find
it!
STOP
Gro
und
tab
stew
mac
.co
m
20
©
2018
Ste
wM
ac
AB
CD
FE
100μ
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
pon
ents
as
th
ey g
o o
nto
th
e ey
elet
b
oar
d .
Inst
ead
wra
p a
ll th
e p
arts
ont
o th
e b
oard
, ben
ding
th
eir l
eads
tigh
tly
so th
e p
arts
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
bac
k ov
er
ever
y st
ep .
Car
eful
insp
ectio
n is
the
bes
t w
ay t
o m
ake
sure
yo
ur a
mp
wor
ks t
he fi
rst
time
you
turn
it o
n .
Sold
erSo
lder
eac
h co
nnec
tion
poi
nt
only
on
ce . R
ehea
tin
g t
o ad
d an
othe
r p
art
mak
es a
mes
sy,
fau
lty
sold
er j
oin
t . U
se t
he
sold
erin
g t
ips
on p
age
11 t
o ge
t pro
fess
iona
l res
ults
.
stew
mac
.co
m
21
©
2018
Ste
wM
ac
Wra
pp
ing
par
ts o
nto
th
e b
ias
bo
ard
The
bia
s b
oar
d i
s th
e sm
alle
r o
f th
e tw
o ey
elet
boa
rds .
Pos
ition
it a
s sh
own
abov
e, w
ith
hole
D t
o th
e up
per
rig
ht,
and
the
pai
r of
mou
ntin
g ho
les
tow
ard
the
bot
tom
.
S
TE
P 4
2
Ad
d t
wo
res
isto
rsW
rap
a 1
00K
resi
stor
bet
wee
n ey
elet
s A
an
d B .
Wra
p a
22K
res
isto
r b
etw
een
eyel
ets
E an
d F .
Do
n’t
sold
er t
hes
e co
nn
ecti
ons
. Yo
u’ll
so
lder
the
con
nect
ions
on
bot
h ey
elet
b
oar
ds
late
r, a
fter
all
thei
r p
arts
are
w
rap
ped
in p
lace
and
dou
ble
-che
cked
.
S
TE
P 4
3
Ad
d a
cap
acit
or
and
a d
iod
eW
rap
a 1
00μF
ele
ctro
lytic
cap
bet
wee
n ey
elet
s E a
nd F .
No
te th
e p
ola
rity
of t
he
cap
acit
or.
Con
nect
the
cap
’s n
egat
ive
lead
to
eyel
et F
. Thi
s ca
pac
itor
conn
ects
ne
xt t
o th
e 22
K re
sist
or in
stal
led
in t
he
pre
vio
us s
tep
. As
you
wra
p t
he
lead
s,
allo
w t
he t
wo
par
ts e
noug
h ro
om t
o si
t si
de-
by-s
ide .
Ad
d th
e re
ctifi
er d
iod
e b
etw
een
eyel
ets
B an
d C
. No
te th
e p
ola
rity
. The
pos
itive
le
ad o
f the
dio
de
is in
dica
ted
by a
str
ipe
at t
hat
en
d . T
he
end
wit
h n
o s
trip
e is
ne
gativ
e . C
onne
ct t
he n
egat
ive
lead
to
eyel
et C
.
S
TE
P 4
4
Ad
d t
wo
wh
ite
jum
per
sC
ut a
1"
whi
te j
ump
er . T
urn
the
eyel
et
boa
rd o
ver,
and
add
this
jum
per
bet
wee
n ey
elet
s C
and
F o
n th
e b
ack
of t
he b
ias
boa
rd .
Cut a
3" w
hite
jum
per
. Wra
p o
ne e
nd u
p
thro
ugh
the
bot
tom
of e
yele
t C, a
nd ru
n th
is ju
mp
er u
p th
roug
h ho
le D
. Pul
l it t
ight
to
kee
p it
in p
lace
.
S
TE
P 4
5
Ad
d t
wo
mo
re ju
mp
ers
Cut
a 6"
gre
en ju
mp
er a
nd w
rap
it o
nto
eyel
et E
from
the
fron
t .
Cut
a 7"
whi
te ju
mp
er a
nd w
rap
it o
nto
eyel
et A
from
the
fron
t .
Set
the
bia
s b
oar
d a
sid
e St
ore
the
bia
s b
oard
som
ewhe
re t
hat
it w
on’t
be
dist
urb
ed . Y
ou’re
read
y to
turn
yo
ur a
tten
tion
to th
e m
ain
eyel
et b
oard
.
stew
mac
.co
m
22
©
2018
Ste
wM
ac
15
34
2
10
59
2017
67
89
11
5857
5655
5460
6162
6364
6568
6970
71 72 73 7466
67
1213
1415
1618
1921
2425
2627
3029
2831
2223
3233
3435
3740
4142
4344
4546
4748
4950
5152
5338
3936
+25μF
250
104J 600V
473J 600V
223J 600V510K
+25μF
+25μF
stew
mac
.co
m
23
©
2018
Ste
wM
ac
Wra
pp
ing
par
ts o
nto
th
e m
ain
bo
ard
S
TE
P 4
6
Inst
all a
25
μF
cap
+ a
1.5
K r
esis
tor
Wra
p t
he le
ads
of a
1 .5
K re
sist
or a
roun
d th
e le
ads
of a
25μ
F Sp
ragu
e el
ectr
olyt
ic
cap
acito
r and
sol
der
them
toge
ther
.
Not
e th
e p
olar
ity
of th
e ca
pac
itor .
Inst
all
this
resi
stor
/cap
acito
r ass
emb
ly b
etw
een
eyel
ets
21 a
nd 7
0, m
akin
g su
re t
he c
a-p
acito
r’s n
egat
ive
lead
goe
s to
eye
let 2
1 .
S
TE
P 4
7
Ad
d t
wo
jum
per
s, g
reen
+ w
hit
eCu
t a 4
" gre
en ju
mp
er a
nd w
rap
one
end
on
to e
yele
t 21 .
Cut a
3-1
/2" w
hite
jum
per
and
wra
p o
ne
end
onto
eye
let 7
0 .
S
TE
P 4
8
Ad
d t
wo
wh
ite
jum
per
sC
ut t
wo
12"
whi
te j
ump
ers .
On
one
of
thes
e, m
ark
the
insu
latio
n at
bot
h en
ds
with
a re
d m
arke
r .
Run
bot
h of
thes
e ju
mp
ers d
own
thro
ugh
hole
20,
acr
oss t
he b
ack
of th
e b
oard
, and
up
thro
ugh
hole
53 .
S
TE
P 4
9
Ad
d a
0.1
μF
cap
acit
or
+ o
ne
jum
per
Wra
p a
0 .1
μF
Ora
ng
e D
rop
cap
acit
or
bet
wee
n ey
elet
s 19
and
69 .
Thi
s ca
pac
-ito
r d
oes
not
have
pol
arit
y an
d c
an b
e in
stal
led
in e
ither
dire
ctio
n .
Cu
t an
8-1
/2"
wh
ite
jum
per
. Tu
rn t
he
boa
rd o
ver a
nd w
rap
this
jum
per
thro
ugh
the
bot
tom
of
eyel
et 1
9 . R
un t
he o
ther
en
d of
the
jum
per
up
thro
ugh
hole
17
and
pul
l it t
ight
so
it st
ays
in p
lace
.
S
TE
P 5
0
0.0
47μ
F ca
pac
ito
r +
on
e ju
mp
erA
dd
a 0
.047
μF
Ora
ng
e D
rop
cap
acit
or
bet
wee
n ey
elet
s 18
and
69 .
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 .
Cu
t an
8-1
/2"
wh
ite
jum
per
an
d m
ark
one
of th
e en
d w
ith b
lue
mar
ker .
Flip
the
boa
rd a
nd w
rap
the
unm
arke
d en
d of
this
ju
mp
er o
nto
the
bac
k of
eye
let
18 . R
un
this
jum
per
up
thro
ugh
hole
17
and
pul
l tig
ht to
kee
p in
pla
ce .
S
TE
P 5
1
100
K r
esis
tor
+ 2
50p
F ca
pac
ito
rW
rap
a 1
00K
resi
sto
r b
etw
een
eye
lets
68
and
69 .
Ad
d a
250
pF
silv
er m
ica
cap
acit
or b
e-tw
een
eyel
ets
68 a
nd 4
2 . T
his
cap
acito
r al
so h
as n
o p
olar
ity
and
can
be
inst
alle
d fa
cing
eith
er w
ay .
S
TE
P 5
2
Inst
all t
wo
wh
ite
jum
per
sA
dd
a 3"
whi
te ju
mp
er to
eye
let 6
8 .
Cut a
5-1
/2"
whi
te ju
mp
er a
nd m
ark
one
end
with
a b
lack
mar
ker .
Turn
the
boa
rd
over
and
wra
p it
s unm
arke
d en
d th
roug
h th
e ba
ck o
f eye
let 4
2 . R
un th
e ot
her e
nd o
f th
is ju
mp
er u
p th
roug
h ho
le 1
7 an
d p
ull
it tig
ht to
kee
p it
in p
lace
.
S
TE
P 5
3
Inst
all t
wo
10
0K
res
isto
rsA
dd
one
100K
res
isto
r b
etw
een
eyel
ets
41 a
nd
68 .
Ad
d a
no
ther
100
K re
sist
or
bet
wee
n ey
elet
s 41
and
67 .
S
TE
P 5
4
Ad
d t
wo
cap
acit
ors
+ a
1M
res
isto
rA
dd
a 0
.022
μF
Ora
ng
e D
rop
cap
acit
or
bet
wee
n ey
elet
s 67
and
40 .
Thi
s ca
p is
no
t pol
ariz
ed .
Ad
d a
500
pF
Silv
er M
ica
cap
acit
or b
e-tw
een
eyel
ets
40 a
nd 3
0 .
Ad
d a
1M
res
isto
r b
etw
een
eye
lets
16
and
30 .
S
TE
P 5
5
Ad
d t
wo
wh
ite
jum
per
sA
dd
a 3"
whi
te ju
mp
er to
eye
let 6
7 .
Cut
one
4" w
hite
jum
per
. Flip
the
boa
rd
over
an
d w
rap
on
e en
d o
f th
e ju
mp
er
thro
ugh
the
bac
k of
eye
let
30 . R
un t
his
jum
per
up
thr
ough
hol
e 52
and
pul
l it
tig
ht .
S
TE
P 5
6
Ad
d t
wo
mo
re c
ap+
resi
sto
r p
airi
ng
sW
rap
the
lead
s of
a 2
.2K
resi
stor
and
a
1 .5K
res
isto
r ar
ou
nd
th
e le
ads
of
two
25μF
Sp
ragu
e el
ectr
olyt
ic c
apac
itors
and
so
lder
them
toge
ther
.
Inst
all
the
2 .2K
res
isto
r/ca
p a
ssem
bly
b
etw
een
eyel
ets
16 a
nd 6
5, a
nd th
e 1 .
5K
resi
stor
/cap
ass
emb
ly b
etw
een
eyel
ets
16 a
nd 6
6 . N
ote
the
pol
arit
y of
the
cap
s,
mak
ing
su
re t
he
neg
ativ
e le
ads
go
to
eyel
et 1
6 .
S
TE
P 5
7
Ad
d t
wo
wh
ite
jum
per
sA
dd
a 3"
whi
te ju
mp
er to
eye
let 6
6 .
Ad
d a
1-1/
2" w
hite
jum
per
to e
yele
t 65 .
70
21
+
25μ
F
Posi
tive
Neg
ativ
e
66
16
65
Posi
tive
+
25μ
F
+
25μ
F
stew
mac
.co
m
24
©20
18 S
tew
Mac
15
34
2
10
59
2017
67
89
11
5857
5655
5460
6162
6364
6568
6970
71 72 73 7466
67
1213
1415
1618
1921
2425
2627
3029
2831
2223
3233
3435
3740
4142
4344
4546
4748
4950
5152
5338
3936
332J 600V
10pF
223J 600V
+25μF
+25μF
+25μF
stew
mac
.co
m
25
©
2018
Ste
wM
ac
S
TE
P 5
8
Ad
d a
gre
en b
ack-
of-
bo
ard
jum
per
Cu
t a
4" g
reen
jum
per
. Flip
th
e ey
elet
b
oard
ove
r and
add
this
jum
per
bet
wee
n ey
elet
16
and
eye
let
21 o
n th
e b
ack
of
the
boa
rd .
S
TE
P 5
9
Ad
d a
3.3
M r
esis
tor
+ a
10
pF
cap
A
dd
a 3 .
3M r
esis
tor
and
a 10
pF
cera
mic
di
sk c
apac
itor b
etw
een
eyel
ets 2
7 an
d 15
. Th
is c
ap is
not
pol
ariz
ed .
S
TE
P 6
0
Ad
d a
470
K r
esis
tor
Ad
d a
470K
res
isto
r b
etw
een
eyel
ets
27
and
14 .
S
TE
P 6
1
Ad
d a
bac
k-o
f-b
oar
d ju
mp
erFl
ip th
e b
oard
ove
r and
add
a 2
-1/4
" whi
te
jum
per
on
the
back
of t
he b
oard
bet
wee
n ey
elet
s 15
and
40 .
S
TE
P 6
2
Ad
d a
.003
3μ
F ca
pac
ito
rA
dd
a .0
033μ
F O
ran
ge
Dro
p c
apac
itor
b
etw
een
eyel
ets
39 a
nd 2
9 . T
his
cap
is
not p
olar
ized
.
S
TE
P 6
3
Ad
d t
hre
e w
hit
e ju
mp
ers
Cut
two
6-1/
2" w
hite
jum
per
s . M
ark
the
end
of o
ne w
ith a
n or
ange
mar
ker .
Flip
th
e b
oar
d o
ver
and
wra
p t
he
un
-m
arke
d en
d of
thi
s ju
mp
er t
hrou
gh t
he
bac
k of
eye
let 2
9 .
Wra
p t
he
seco
nd
ju
mp
er t
hro
ug
h t
he
bac
k of
eye
let 1
4 .
Run
bot
h th
ese
jum
per
s up
thro
ugh
hole
13
and
pul
l the
m t
ight
to
keep
the
m in
p
lace
.
Flip
the
boa
rd o
ver a
nd a
dd a
1-1
/4" w
hite
ju
mp
er o
n th
e ba
ck o
f the
boa
rd b
etw
een
eyel
ets
39 a
nd 6
4 .
S
TE
P 6
4
Ad
d t
wo
10
0K
res
isto
rs +
on
e ca
pA
dd
a 10
0K r
esis
tor
bet
wee
n ey
elet
s 38
an
d 6
4 . A
dd
an
oth
er 1
00K
resi
stor
be-
twee
n ey
elet
s 38
and
62 .
Ad
d a
0 .02
μF O
rang
e D
rop
cap
bet
wee
n ey
elet
s 37
and
62 .
Thi
s ca
pac
itor
is n
ot
pol
ariz
ed .
S
TE
P 6
5
Ad
d t
wo
wh
ite
jum
per
sA
dd
one
3" ju
mp
er to
eye
let 6
4 .
Ad
d on
e 4-
1/2"
jum
per
to e
yele
t 62 .
S
TE
P 6
6
Ad
d a
cap
+ r
esis
tor
pai
rin
gW
rap
the
lead
s of
a 1
.5K
resi
stor
aro
und
the
lead
s of
a 2
5μF
Spra
gue
elec
trol
ytic
ca
pac
itor a
nd s
old
er th
em to
geth
er .
Not
e th
e p
olar
ity
of th
e ca
pac
itor .
Inst
all
this
resi
stor
/cap
acito
r ass
emb
ly b
etw
een
eyel
ets
12 a
nd 6
1, m
akin
g s
ure
the
ca-
pac
itor’s
neg
ativ
e le
ad g
oes
to e
yele
t 12 .
S
TE
P 6
7
Ad
d t
wo
res
isto
rsA
dd
a 2
.7k
resi
stor
bet
wee
n ey
elet
s 12
an
d 26
.
Ad
d a
47o
hm r
esis
tor
bet
wee
n ey
elet
s 11
and
12 .
S
TE
P 6
8
Thre
e ju
mp
ers
Ad
d a
2" w
hite
jum
per
to e
yele
t 61 .
Cut
one
7" w
hite
jum
per
. Flip
the
boa
rd
over
an
d w
rap
on
e en
d o
f th
e ju
mp
er
thro
ugh
the
bot
tom
of e
yele
t 26 .
Run
the
othe
r end
of t
he ju
mp
er u
p th
roug
h ho
le
48 a
nd p
ull t
ight
to k
eep
in p
lace
.
Cut
one
5" w
hite
jum
per
. Flip
the
boa
rd
over
an
d w
rap
on
e en
d o
f th
e ju
mp
er
thro
ugh
the
bot
tom
of e
yele
t 27 .
Run
the
othe
r end
of t
he ju
mp
er u
p th
roug
h ho
le
49 a
nd p
ull t
ight
to k
eep
in p
lace
.
S
TE
P 6
9
Ad
d t
wo
mo
re c
ap+
resi
sto
r p
airi
ng
sW
rap
the
lead
s of
a 3
.3K
resi
stor
and
a
1 .5K
res
isto
r ar
ou
nd
th
e le
ads
of
two
25μF
Sp
ragu
e el
ectr
olyt
ic c
apac
itors
and
sold
er th
em to
geth
er .
Inst
all
the
3 .3K
res
isto
r/ca
p a
ssem
bly
b
etw
een
eyel
ets
11 a
nd 5
9, a
nd th
e 1 .
5K
resi
stor
/cap
ass
emb
ly b
etw
een
eyel
ets
11 a
nd 6
0 . N
ote
the
pol
arit
y of
the
cap
s,
mak
ing
su
re t
he
neg
ativ
e le
ads
go
to
eyel
et 1
1 .
61
12
+
25μ
F
Posi
tive
Neg
ativ
e
60
11
59
Posi
tive
+
25μ
F
+
25μ
F
stew
mac
.co
m
26
©
2018
Ste
wM
ac
15
34
2
10
59
2017
67
89
11
5857
5655
5460
6162
6364
6568
6970
71 72 73 7466
67
1213
1415
1618
1921
2425
2627
3029
2831
2223
3233
3435
3740
4142
4344
4546
4748
4950
5152
5338
3936
.01μF .01μF .02μF
104J 600V
223J 600V
104J 600V
104J 600V
stew
mac
.co
m
27
©20
18 S
tew
Mac
S
TE
P 7
0
Ad
d t
hre
e ju
mp
ers,
wh
ite
and
gre
enCu
t tw
o 4-
1/2"
whi
te ju
mp
ers .
Ad
d on
e to
eye
let 6
0 an
d th
e ot
her t
o ey
elet
59 .
Cut
one
3" g
reen
jum
per
. Flip
the
boa
rd
over
and
ad
d th
is ju
mp
er b
etw
een
eye-
lets
11
and
6 on
the
bac
k of
the
boa
rd .
S
TE
P 7
1
Ad
d t
wo
1M
res
isto
rsA
dd
a 1
M r
esis
tor
bet
wee
n e
yele
ts 9
an
d 11
.
Add
ano
ther
1M
resi
stor
bet
wee
n ey
elet
s 25
and
59 .
S
TE
P 7
2
Ad
d t
hre
e ce
ram
ic d
isk
cap
acit
ors
The
thre
e ca
pac
itors
inst
alle
d in
this
step
ar
e no
t pol
ariz
ed, s
o yo
u ca
n in
stal
l the
m
in e
ither
dire
ctio
n .
Ad
d a
0 .02
μF c
eram
ic d
isk
cap
bet
wee
n ey
elet
s 58
and
36 .
Ad
d a
0 .01
μF c
eram
ic d
isk
cap
bet
wee
n ey
elet
s 36
and
25 .
Ad
d a
0 .01
μF c
eram
ic d
isk
cap
bet
wee
n ey
elet
s 25
and
9 .
S
TE
P 7
3
Ad
d t
wo
wh
ite
jum
per
sCu
t on
e 8"
whi
te j
ump
er a
nd a
dd
it t
o ey
elet
9 . R
un th
is ju
mp
er d
own
thro
ugh
ho
le 1
0, a
cros
s th
e b
ack
of
the
eyel
et
boa
rd a
nd b
ack
up th
roug
h ho
le 4
7 . P
ull
it tig
ht to
kee
p it
in p
lace
.
Cut
one
7" w
hite
jum
per
. Mar
k on
e en
d w
ith a
blu
e m
arke
r . W
rap
the
unm
arke
d en
d on
to e
yele
t 25 .
Run
the
mar
ked
end
dow
n th
roug
h ho
le 1
0, a
cros
s th
e b
ack
of
the
bo
ard
an
d u
p t
hro
ug
h h
ole
47 .
Pu
ll it
tight
.
S
TE
P 7
4
Ad
d t
hre
e w
hit
e ju
mp
ers
Ad
d a
2" w
hite
jum
per
to e
yele
t 58 .
Cut
one
7" w
hite
jum
per
. Mar
k on
e en
d w
ith a
blu
e m
arke
r . Fl
ip t
he b
oard
ove
r an
d w
rap
the
unm
arke
d en
d th
roug
h th
e b
ack
of e
yele
t 36 .
Run
the
mar
ked
end
up
thro
ugh
hole
7 a
nd p
ull i
t tig
ht .
Flip
th
e b
oar
d a
gai
n a
nd
ad
d a
1-1
/4"
jum
per
bet
wee
n ey
elet
s 57
an
d 5
8 on
th
e b
ack
of th
e b
oard
.
S
TE
P 7
5
Ad
d a
res
isto
r, a
cap
+ a
jum
per
Ad
d a
1M
res
isto
r b
etw
een
eye
lets
57
and
35 .
Ad
d a
0 .1μ
F O
rang
e D
rop
cap
bet
wee
n ey
elet
s 35
and
8 . T
his c
ap is
not
pol
ariz
ed .
Cut a
6" w
hite
jum
per
. Flip
the
boa
rd o
ver
and
wra
p o
ne e
nd t
hrou
gh t
he b
ack
of
eyel
et 8
. Run
this
jum
per
up
thro
ugh
hole
7
and
pul
l it t
ight
.
S
TE
P 7
6
Ad
d o
ne
cap
acit
or
+ o
ne
resi
sto
rA
dd
a 0
.02μ
F O
ran
ge
Dro
p c
apac
ito
r b
etw
een
eyel
ets
6 an
d 35
. Thi
s ca
p is
not
p
olar
ized
.
Ad
d a
220K
res
isto
r b
etw
een
eyel
ets
34
and
57 .
S
TE
P 7
7
Ad
d t
hre
e re
sist
ors
Ad
d a
1M
res
isto
r b
etw
een
eye
lets
33
and
56 .
Ad
d a
1K
resi
sto
r b
etw
een
eye
lets
33
and
55 .
Ad
d a
56k
res
isto
r b
etw
een
eyel
ets
33
and
6 .
S
TE
P 7
8
Ad
d t
hre
e ju
mp
ers
Ad
d a
1-1/
2" w
hite
jum
per
to e
yele
t 56 .
Ad
d a
2" w
hite
jum
per
to e
yele
t 55 .
Ad
d a
6" g
reen
jum
per
to e
yele
t 6 .
S
TE
P 7
9
Two
res
isto
rs +
on
e ca
pac
ito
rA
dd
one
220K
res
isto
r b
etw
een
eyel
ets
5 an
d 24
. Ad
d an
othe
r 22
0K r
esis
tor
be-
twee
n ey
elet
s 3
and
24 .
Ad
d a
0 .1μ
F O
rang
e D
rop
cap
acito
r b
e-tw
een
eyel
ets
5 an
d 55
. Thi
s ca
p is
not
p
olar
ized
.
S
TE
P 8
0
Ad
d o
ne
resi
sto
r +
on
e ca
pac
ito
rA
dd
a 5
6k r
esis
tor
bet
wee
n ey
elet
s 44
an
d 32
.
Ad
d a
0 .1μ
F O
rang
e D
rop
cap
bet
wee
n ey
elet
s 3
and
44 . T
his
cap
isn’
t pol
ariz
ed .
stew
mac
.co
m
28
©
2018
Ste
wM
ac
15
34
2
10
59
2017
67
89
11
5857
5655
5460
6162
6364
6568
6970
71 72 73 7466
67
1213
1415
1618
1921
2425
2627
3029
2831
2223
3233
3435
3740
4142
4344
4546
4748
4950
5152
5338
3936
stew
mac
.co
m
29
©20
18 S
tew
Mac
S
TE
P 8
3
Ad
d s
ix w
hit
e ju
mp
ers
Ad
d a
1" w
hite
jum
per
on
the
bac
k of
the
boa
rd b
etw
een
eyel
ets
2 an
d 22
.
Ad
d a
6" w
hite
jum
per
to e
yele
t 54 .
Cut a
2" w
hite
jum
per
. Flip
the
boa
rd o
ver
and
wra
p o
ne e
nd t
hrou
gh t
he b
ack
of
eyel
et 1
. Run
this
jum
per
up
thro
ugh
hole
71
and
pul
l it t
ight
.
Cut a
1-3
/4" w
hite
jum
per
. Flip
the
boa
rd
and
wra
p it
to th
e b
ack
of e
yele
t 22 .
Run
it
up th
roug
h ho
le 7
2 an
d p
ull i
t tig
ht .
Cut a
5" w
hite
jum
per
. Flip
the
boa
rd a
nd
wra
p it
to th
e b
ack
of e
yele
t 22 .
Run
the
this
jum
per
up
thro
ugh
hole
73
and
pul
l it
tight
.
Cut a
2" w
hite
jum
per
. Flip
the
boa
rd a
nd
wra
p it
to th
e b
ack
of e
yele
t 54 .
Run
it u
p
thro
ugh
hole
74
and
pul
l it t
ight
.
S
TE
P 8
4
Ad
d t
wo
flyi
ng
jum
per
sFl
ying
jum
per
s ar
e w
ires
that
trav
el o
ver
the
boa
rd, j
ump
ing
from
one
eye
let
to
anot
her .
Thes
e ar
e ve
ry c
omm
on in
cla
ssic
p
oint
-to
-poi
nt c
ircui
ts .
Cut a
4" w
hite
jum
per
. Flip
the
boa
rd o
ver
and
wra
p o
ne e
nd t
hrou
gh t
he b
ack
of
eyel
et 4
1 . R
un t
his
jum
per
up
thr
oug
h ho
le 3
1, p
ull i
t tig
ht, a
nd ru
n it
bac
k do
wn
thro
ugh
hole
51 .
Wra
p t
his
end
thro
ugh
the
bac
k of
eye
let 3
8 .
Cut a
7" w
hite
jum
per
. Flip
the
boa
rd a
nd
wra
p it
to th
e b
ack
of e
yele
t 63 .
Run
this
ju
mp
er u
p t
hrou
gh h
ole
51, p
ull i
t tig
ht,
and
leav
e th
e en
d of
thi
s fly
ing
for
now
. Yo
u’ll
be
twis
ting
this
lead
toge
ther
with
ot
her fl
ying
lead
s .
S
TE
P 8
5
Ad
d t
wo
mo
re fl
yin
g ju
mp
ers
Cut
a 1
2" w
hite
jum
per
. Flip
the
boa
rd
and
wra
p t
his
jum
per
thr
ough
the
bac
k of
eye
let 3
8 . R
un th
e fr
ee e
nd u
p th
roug
h ho
le 5
1 an
d p
ull i
t tig
ht . L
eave
thi
s en
d fly
ing
for n
ow .
Cut a
6-1
/2" w
hite
jum
per
. Flip
the
boa
rd
and
wra
p o
ne e
nd t
hrou
gh t
he b
ack
of
eyel
et 3
7 . R
un t
his
jum
per
up
thr
oug
h ho
le 5
0 an
d p
ull i
t tig
ht .
S
TE
P 8
6
Twis
t th
e fl
yin
g ju
mp
ers
Car
eful
ly tw
ist t
hese
thre
e fly
ing
jum
per
s to
geth
er, b
endi
ng t
hem
tow
ard
the
left
si
de o
f the
boa
rd . Y
ou w
ant t
hese
jum
per
s to
be
up a
nd
aw
ay f
rom
com
pon
ents
. Be
car
eful
not
to
dist
urb
the
ir w
rap
ped
co
nnec
tions
to th
e ey
elet
s .
Rev
iew
th
is p
age
bef
ore
sta
rtin
gTh
e di
agra
m sh
ows a
lot o
f jum
per
s now
, so
it’s
a g
ood
idea
to re
ad th
e st
eps
and
unde
rsta
nd w
here
eac
h w
ire g
oes b
efor
e di
ving
in .
S
TE
P 8
1
Ad
d fo
ur
wh
ite
jum
per
sA
dd
a 3"
jum
per
to e
yele
t 44 .
Cut a
6" w
hite
jum
per
. Flip
the
boa
rd o
ver
and
wra
p o
ne e
nd t
hrou
gh t
he b
ack
of
eyel
et 2
4 . R
un t
his
jum
per
up
thr
ough
ho
le 4
and
pul
l it t
ight
.
Cut a
4-1
/2" w
hite
jum
per
. Flip
the
boa
rd
and
wra
p it
thro
ugh
the
bac
k of
eye
let 5
. Ru
n th
is ju
mp
er u
p th
roug
h ho
le 4
3 an
d p
ull i
t tig
ht to
kee
p it
in p
lace
.
Cut a
6" w
hite
jum
per
. Flip
the
boa
rd a
nd
wra
p th
is o
nto
the
bac
k of
eye
let 3
. Run
it
up th
roug
h ho
le 4
3 an
d p
ull i
t tig
ht .
ST
EP
82
Ad
d t
wo
res
isto
rsA
dd
a 1
K 2W
res
isto
r b
etw
een
eye
lets
54
and
22 .
Ad
d a
15K
2W r
esis
tor
bet
wee
n ey
elet
s 22
and
1 .
stew
mac
.co
m
30
©
2018
Ste
wM
ac
15
34
2
10
59
2017
67
89
11
5857
5655
5460
6162
6364
6568
6970
71 72 73 7466
67
1213
1415
1618
1921
2425
2627
3029
2831
2223
3233
3435
3740
4142
4344
4546
4748
4950
5152
5338
3936
stew
mac
.co
m
31
©
2018
Ste
wM
ac
S
TE
P 8
7
Iden
tify
th
e fl
yin
g ju
mp
ers
Use
a m
ulti
met
er t
o id
enti
fy t
he fl
ying
ju
mp
er t
hat
has
cont
inui
ty t
o ey
elet
63 .
Ru
n th
at ju
mp
er d
own
thro
ugh
hole
46
and
wra
p it
thro
ugh
the
bac
k of
eye
let 3
4 .
Fin
d t
he
flyin
g j
ump
er w
ith
cont
inui
ty
to e
yele
t 37 .
Wra
p th
e en
d of
this
jum
per
d
own
onto
eye
let 5
6 .
S
TE
P 8
8
Ad
d t
wo
wh
ite
jum
per
sCu
t a 6
" whi
te ju
mp
er . F
lip th
e b
oard
ove
r an
d w
rap
one
end
thr
ough
the
bac
k of
ey
elet
34 .
Run
thi
s ju
mp
er u
p t
hrou
gh
hole
46,
pul
l it
tight
, and
tw
ist
it in
with
th
e fly
ing
jum
per
stil
l rem
aini
ng a
bov
e th
e b
oard
.
Cu
t a
6" w
hit
e ju
mp
er .
Flip
th
e b
oar
d an
d w
rap
it t
hrou
gh t
he b
ack
of e
yele
t 32
. Run
thi
s ju
mp
er u
p t
hrou
gh h
ole
45,
pul
l it t
ight
, and
twis
t it i
n w
ith th
e fly
ing
jum
per
s .
S
TE
P 8
9
Inst
alli
ng
flyi
ng
jum
per
sU
se a
mul
timet
er to
find
the
flyin
g ju
mp
er
with
con
tinui
ty to
eye
let 3
2 . W
rap
the
end
of th
is ju
mp
er o
nto
eyel
et 1
.
Find
the
flyin
g ju
mp
er w
ith c
ontin
uity
to
eyel
et 3
4 . W
rap
the
end
of
this
jum
per
d
own
onto
eye
let 2
.
The
one
rem
aini
ng fl
ying
jum
per
will
be
sold
ered
to th
e fil
ter c
apac
itor l
ater
.
Sto
p a
nd
rev
iew
Now
all
the
com
pon
ents
and
wire
s are
on
the
eyel
et b
oard
. Sto
p a
nd t
ake
a b
reak
so
you
’ll h
ave
fres
h ey
es t
o re
view
you
r w
ork
bef
ore
sold
erin
g .
Mak
e su
re y
ou’v
e fo
llow
ed
each
step
cor
rect
ly . I
t wou
ld
be
surp
risi
ng
to
fin
d n
o m
ista
kes
at t
his
poi
nt, a
nd
it’s
muc
h le
ss w
ork
to fi
nd a
nd fi
x th
em
now
rath
er th
an a
fter
sol
der
ing!
As
you
’re
chec
kin
g y
ou
r w
ork
, m
ake
sure
all
your
con
nect
ions
are
tigh
t . D
on’t
coun
t on
sol
der
to
“glu
e” y
our
join
ts—
mak
e th
em m
ech
anic
ally
tig
ht
bef
ore
so
lder
is e
ver a
pp
lied
.
S
TE
P 9
0
Sold
er b
oth
eye
let
bo
ard
sTh
e co
mp
onen
ts a
nd ju
mp
ers a
re o
n th
e b
oard
s an
d d
oub
le-c
heck
ed f
or c
orre
ct
pla
cem
ent
and
tight
wra
ps .
It’s
tim
e se
t th
e co
nnec
tions
with
sol
der
.
Revi
ew “T
ips f
or g
reat
sold
erin
g” o
n p
age
11, t
hen
sold
er e
ach
conn
ectio
n on
the
ey
elet
boa
rd .
Aft
er a
ll th
e jo
ints
are
sol
der
ed, c
lip t
he
exce
ss le
ads
on th
e fr
ont a
nd b
ack
of th
e b
oar
d . T
rim
min
g t
hes
e ex
cess
lea
ds
is
imp
orta
nt to
avo
id a
shor
t in
your
circ
uit .
Che
ck a
ll yo
ur s
old
er j
oint
s to
see
tha
t th
ey’re
shi
ny, a
nd to
mak
e su
re t
hat
you
have
n’t m
isse
d on
e .
SLOW
STOP
stew
mac
.co
m
32
©
2018
Ste
wM
ac
VIB
RAT
OPE
DA
LRE
VER
BPE
DA
LRE
VER
BO
UTP
UT
REV
ERB
INPU
TSP
EAK
ERPO
WER
GRO
UN
DFU
SEEX
TEN
SIO
N
PILO
TLA
MP
V7
5AR4
V6
6V6
V5
6V6
V4
12A
X7
V3
12A
X7
V2
12AT
7V
112
AX
7
INTE
NSI
TYSP
EED
REV
ERB
BA
SSTR
EBLE
VO
LUM
EIN
STRU
MEN
TS
21
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
OU
X
Y
O
–
U
X
Y
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
15
34
2
10
59
2017
67
89
11
5857
5655
5460
6162
6364
6568
6970
71 72 73 7466
67
1213
1415
1618
1921
2425
2627
3029
2831
2223
3233
3435
3740
4142
4344
4546
4748
4950
5152
5338
3936
+25μF
250250
104J 600V
473J 600V
223J 600V510K
+25μF
+25μF
332J 600V
10pF
223J 600V
+25μF
+25μF
+25μF
.01μF .01μF .02μF
104J 600V
223J 600V104J 600V
104J 600V
AB
CD
FE
100μ
f 10
0μf
stew
mac
.co
m
33
©
2018
Ste
wM
ac
S
TE
P 9
1
Inst
all t
he
bo
ard
s in
th
e ch
assi
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
th
e u
nso
lder
ed j
um
per
s co
min
g th
roug
h ho
les
20 a
nd 5
3 ha
ve e
noug
h le
ngth
to re
ach
thei
r com
pon
ents
. Pla
ce
the
eyel
et b
oard
in t
he c
hass
is w
here
it
will
be
mou
nted
and
adj
ust t
hese
jum
p-
ers
until
they
reac
h th
eir c
omp
onen
ts .
Lay
the
mai
n in
sula
tor b
oard
on
the
bot
-to
m o
f th
e ch
assi
s, a
ligni
ng it
wit
h th
e m
ount
ing
hole
s . A
lign
the
mai
n ey
elet
b
oard
ove
r th
e in
sula
tor
boa
rd . P
ass
a 6-
32 x
1/2
" m
achi
ne s
crew
thr
ough
the
ey
elet
bo
ard
, th
e in
sula
tor
bo
ard
, an
d th
e ch
assi
s . S
ecur
e it
with
a lo
cknu
t on
th
e ou
tsid
e of
the
cha
ssis
. Do
the
sam
e w
ith th
e se
cond
bol
t .
Inst
all t
he b
ias
boa
rd in
the
sam
e w
ay:
insu
lato
r fir
st, e
yele
t b
oard
on
top
and
m
ou
nte
d w
ith
6-3
2 x
1/2
" m
ach
ine
scre
ws .
S
TE
P 9
2
Sold
er t
ub
e so
cket
V7
Wra
p t
he w
hite
jum
per
fro
m e
yele
t 54
on
to p
in 8
on
tub
e so
cket
V7
alon
g w
ith
the
yello
w p
ower
tran
sfor
mer
lead
.
Wra
p t
he w
hite
jum
per
from
bia
s b
oard
ey
elet
A o
nto
pin
4 o
f soc
ket V
7 .
Sold
er a
ll th
e co
nnec
tions
to t
his
sock
et
(six
wire
s) a
nd tr
im th
e ex
cess
wire
end
s .
S
TE
P 9
3
Sold
er t
ub
e so
cket
V6
Test
the
tw
o ju
mp
ers
com
ing
from
hol
e 43
to id
entif
y th
e on
e w
ith c
ontin
uity
to
eyel
et 3
. Sol
der
thi
s ju
mp
er t
o p
in 5
of
sock
et V
6 .
You
sh
ou
ld h
ave
jum
per
s so
lder
ed t
o p
ins
3, 4
, 5 a
nd 8
. Sol
der
any
uns
old
ered
co
nnec
tions
on
this
soc
ket n
ow a
nd tr
im
the
wire
end
s .
S
TE
P 9
4
Sold
er t
ub
e so
cket
V5
Sold
er t
he
oth
er j
ump
er c
om
ing
fro
m
ho
le 4
3 to
pin
5 o
f so
cket
V5 .
Tes
t to
m
ake
sure
thi
s ju
mp
er h
as c
ontin
uity
to
eyel
et 5
.
Sold
er t
he ju
mp
er c
omin
g fr
om h
ole
73
to p
in 4
of s
ocke
t V5 .
Thi
s ju
mp
er s
houl
d ha
ve c
ontin
uity
to e
yele
t 22 .
You
sh
ou
ld h
ave
jum
per
s so
lder
ed t
o p
ins
3, 4
, 5 a
nd 8
. Sol
der
any
uns
old
ered
co
nnec
tions
on
this
soc
ket n
ow a
nd tr
im
the
wire
end
s .
S
TE
P 9
5
Sold
er t
ub
e so
cket
V4
Wra
p th
e ju
mp
er fr
om e
yele
t 44
to p
in 6
of
soc
ket V
4 .
Wra
p th
e ju
mp
er fr
om e
yele
t 58
to p
in 1
of
soc
ket V
4 .
Wra
p th
e ju
mp
er fr
om e
yele
t 56
to p
in 7
of
soc
ket V
4 .
Wra
p th
e ju
mp
er fr
om e
yele
t 55
to p
in 8
of
soc
ket V
4 .
Test
th
e tw
o ju
mp
ers
com
ing
thr
oug
h ho
le 4
7 to
see
whi
ch o
ne h
as c
ontin
uity
to
eye
let 9
. Sol
der
this
jum
per
to p
in 2
of
sock
et V
4 .
Wra
p th
e ju
mp
er fr
om e
yele
t 59
to p
in 3
of
soc
ket V
4 .
Sold
er th
e co
nnec
tions
to th
is s
ocke
t (si
x w
ires)
. Trim
the
wire
end
s .
S
TE
P 9
6
Sold
er t
ub
e so
cket
V3
Wra
p th
e ju
mp
er fr
om e
yele
t 62
to p
in 6
of
sock
et V
3 . R
un th
is le
ad a
long
the
floor
of
the
chas
sis t
o th
e ot
her s
ide
of th
e tu
be
sock
et . T
his l
ead
carr
ies h
igh
volt
age
and
runn
ing
it ag
ains
t the
floo
r hel
ps d
ista
nce
it fr
om o
ther
wire
s—w
hich
cou
ld c
reat
e un
wan
ted
hum
.
Wra
p th
e ju
mp
er fr
om e
yele
t 64
to p
in 1
of
soc
ket V
3 .
Wra
p th
e ju
mp
er c
omin
g th
roug
h ho
le 4
9 to
pin
7 o
f soc
ket V
3 . T
his
jum
per
sho
uld
have
con
tinui
ty to
eye
let 2
7 .
Wra
p th
e ju
mp
er fr
om e
yele
t 60
to p
in 3
of
soc
ket V
3 .
Wra
p th
e ju
mp
er fr
om e
yele
t 61
to p
in 8
of
soc
ket V
3 .
Wra
p th
e ju
mp
er c
omin
g fr
om th
e re
verb
p
edal
jack
to p
in 2
of s
ocke
t V3 .
Sold
er th
e co
nnec
tions
to th
is s
ocke
t (si
x w
ires)
. Trim
the
wire
end
s .
Inst
alli
ng
an
d s
old
erin
g t
he
bo
ard
s
stew
mac
.co
m
34
©
2018
Ste
wM
ac
VIB
RAT
OPE
DA
LRE
VER
BPE
DA
LRE
VER
BO
UTP
UT
REV
ERB
INPU
TSP
EAK
ERPO
WER
GRO
UN
DFU
SEEX
TEN
SIO
N
PILO
TLA
MP
V7
5AR4
V6
6V6
V5
6V6
V4
12A
X7
V3
12A
X7
V2
12AT
7V
112
AX
7
INTE
NSI
TYSP
EED
REV
ERB
BA
SSTR
EBLE
VO
LUM
EIN
STRU
MEN
TS
21
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
OU
X
Y
O
–
U
X
Y
6
4321
98 7 5
6
4321
98 7 56
4321
98 7 5
6
4321
98 7 5
15
34
2
10
59
2017
67
89
11
5857
5655
5460
6162
6364
6568
6970
71 72 73 7466
67
1213
1415
1618
1921
2425
2627
3029
2831
2223
3233
3435
3740
4142
4344
4546
4748
4950
5152
5338
3936
AB
CD
FE
+25μF
250250
104J 600V
473J 600V
223J 600V510K
+25μF
+25μF
332J 600V
10pF
223J 600V
+25μF
+25μF
+25μF
.01μF .01μF .02μF
104J 600V
223J 600V
104J 600V
104J 600V
100μ
f 10
0μf
stew
mac
.co
m
35
©
2018
Ste
wM
ac
S
TE
P 9
7
Sold
er t
ub
e so
cket
V2
Wra
p t
he ju
mp
er fr
om h
ole
52 o
nto
pin
7
of s
ocke
t V2
. Thi
s ju
mp
er s
houl
d ha
ve
cont
inui
ty to
eye
let 3
0 .
Wra
p th
e ju
mp
er fr
om e
yele
t 65
onto
pin
8
of s
ocke
t V2 .
Do
ub
le-c
hec
k to
be
sure
th
e ju
mp
er
from
pin
7 t
o p
in 2
is s
ecur
ely
wra
pp
ed
onto
pin
7 .
Als
o m
ake
sure
the
jum
per
from
pin
8 to
p
in 3
is w
rap
ped
in p
lace
on
pin
8 .
Sold
er th
e co
nnec
tions
to th
is s
ocke
t (si
x w
ires)
. Trim
the
wire
end
s .
S
TE
P 9
8
Sold
er t
ub
e so
cket
V1
Wra
p th
e ju
mp
er fr
om e
yele
t 67
onto
pin
6
on s
ocke
t V1 .
Wra
p th
e ju
mp
er fr
om e
yele
t 68
onto
pin
1
of s
ocke
t V1 .
Wra
p t
he
un
mar
ked
ju
mp
er c
om
ing
thro
ugh
hole
53
onto
pin
7 o
f soc
ket V
1 .
Wra
p th
e ju
mp
er fr
om e
yele
t 66
onto
pin
8
of s
ocke
t V1 .
Wra
p t
he r
ed m
arke
d ju
mp
er fr
om h
ole
53 o
nto
pin
2 o
f soc
ket V
1 .
Wra
p th
e ju
mp
er fr
om e
yele
t 70
onto
pin
3
of s
ocke
t V1 .
Sold
er th
e co
nnec
tions
to th
is s
ocke
t (si
x w
ires)
. Trim
the
wire
end
s .
S
TE
P 9
9
Sold
er t
he
inst
rum
ent
inp
ut
jack
sSo
lder
the
red
-mar
ked
jum
per
from
hol
e 20
ont
o th
e tw
iste
d p
air
of 6
8K r
esis
tor
lead
s co
min
g fr
om th
e in
put
jack
s .
Sold
er t
he g
reen
jum
per
from
eye
let
21
onto
the
right
lug
of in
put
jack
1 .
Sold
er a
ny r
emai
nin
g u
nsol
der
ed c
on-
nect
ions
on
the
inp
ut ja
cks
and
trim
the
exce
ss w
ires .
ST
EP
10
0
Sold
er t
he
volu
me
po
tSo
lder
the
unm
arke
d ju
mp
er f
rom
hol
e 20
to th
e m
iddl
e lu
g of
the
volu
me
pot
.
Cut
a 1"
gre
en ju
mp
er a
nd r
emov
e th
e sh
ield
ing .
Sol
der
one
end
of
this
to
the
left
lu
g o
f th
e vo
lum
e p
ot . S
old
er t
he
othe
r end
to th
e b
ack
of th
e vo
lum
e p
ot .
S
TE
P 1
01
Sold
er t
he
treb
le p
ot
Find
the
jum
per
com
ing
thro
ugh
hole
17
that
you
mar
ked
wit
h b
lack
ink .
Sol
der
th
is to
the
right
lug
of th
e tr
eble
pot
.
S
TE
P 1
02
Sold
er t
he
bas
s p
ot
Twis
t th
e tw
o ju
mp
ers
toge
ther
that
are
co
min
g th
roug
h ho
le 1
7 . Id
entif
y w
hich
of
thes
e ju
mp
ers h
as c
ontin
uity
to e
yele
t 19
and
sol
der
it to
the
mid
dle
lug
of t
he
bas
s p
ot a
long
with
the
jum
per
alre
ady
in p
lace
.
Fin
d t
he
blu
e-m
arke
d j
um
per
co
min
g th
roug
h ho
le 1
7 th
at h
as c
onti
nuit
y to
ey
elet
18 .
Sol
der
thi
s ju
mp
er t
o th
e le
ft
lug
of th
e b
ass p
ot a
long
with
the
resi
stor
le
ad a
lread
y in
pla
ce .
S
TE
P 1
03
Sold
er t
he
reve
rb p
ot
Take
the
tw
o ju
mp
ers
com
ing
thro
ugh
hole
13
and
twis
t the
m to
geth
er . I
dent
ify
the
jum
per
that
you
mar
ked
oran
ge, a
nd
sold
er it
to th
e rig
ht lu
g of
the
reve
rb p
ot .
Fin
d t
he
jum
per
com
ing
thr
oug
h h
ole
13 t
hat
has
cont
inui
ty t
o ey
elet
14 .
Sol
-d
er t
his
jum
per
to
the
mid
dle
lug
of t
he
reve
rb p
ot .
Cut
a 1"
gre
en ju
mp
er a
nd r
emov
e th
e sh
ield
ing .
Sol
der
one
end
of
this
to
the
left
lug
of th
e re
verb
pot
. Sol
der t
he o
ther
en
d to
the
bac
k of
the
reve
rb p
ot .
stew
mac
.co
m
36
©
2018
Ste
wM
ac
VIB
RAT
OPE
DA
LRE
VER
BPE
DA
LRE
VER
BO
UTP
UT
REV
ERB
INPU
TSP
EAK
ERPO
WER
GRO
UN
DFU
SEEX
TEN
SIO
N
PILO
TLA
MP
V7
5AR4
V6
6V6
V5
6V6
V4
12A
X7
V3
12A
X7
V2
12AT
7V
112
AX
7
INTE
NSI
TYSP
EED
REV
ERB
BA
SSTR
EBLE
VO
LUM
EIN
STRU
MEN
TS
21
OU
X
Y
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
VIB
RAT
OPE
DA
LRE
VER
BPE
DA
LRE
VER
BO
UTP
UT
REV
ERB
INPU
TSP
EAK
ERPO
WER
GRO
UN
DFU
SEEX
TEN
SIO
N
PILO
TLA
MP
V7
5AR4
V6
6V6
V5
6V6
V4
12A
X7
V3
12A
X7
V2
12AT
7V
112
AX
7
15
34
2
10
59
2017
67
89
11
5857
5655
5460
6162
6364
6568
6970
71 72 73 7466
67
1213
1415
1618
1921
2425
2627
3029
2831
2223
3233
3435
3740
4142
4344
4546
4748
4950
5152
5338
3936
AB
CD
FE
100μ
f
+25μF
250250
104J 600V
473J 600V
223J 600V510K 510K
+25μF
+25μF
332J 600V
10pF
223J 600V
+25μF
+25μF
+25μF
.01μF .01μF .02μF
104J 600V
223J 600V104J 600V
104J 600V
stew
mac
.co
m
37
©
2018
Ste
wM
ac
S
TE
P 1
04
Sold
er t
he
spee
d p
ot
Fin
d t
he
jum
per
com
ing
thr
oug
h h
ole
7 th
at y
ou
mar
ked
wit
h b
lue
ink .
Th
is
sho
uld
hav
e co
nti
nu
ity
to e
yele
t 36
. So
lder
this
jum
per
to th
e rig
ht lu
g of
the
spee
d p
ot .
S
TE
P 1
05
Sold
er t
he
inte
nsi
ty p
ot
Iden
tify
the
jum
per
com
ing
thro
ugh
hole
7
that
has
con
tinui
ty t
o ey
elet
8 . S
old
er
this
to
the
right
lug
of t
he in
tens
ity
pot
af
ter t
wis
ting
it to
geth
er w
ith th
e ju
mp
er
from
hol
e 4 .
The
jum
per
co
min
g t
hro
ug
h h
ole
4
shou
ld h
ave
cont
inui
ty to
eye
let 2
4 . S
ol-
der
thi
s ju
mp
er t
o th
e m
iddl
e lu
g of
the
in
tens
ity
pot
.
Fin
d t
he
jum
per
com
ing
thr
oug
h h
ole
D o
f th
e b
ias
boa
rd t
hat
has
cont
inui
ty
to e
yele
t C o
f the
bia
s b
oard
. Sol
der
this
ju
mp
er to
the
left
lug
of th
e in
tens
ity
pot
.
S
TE
P 1
06
Sold
er t
he
filt
er c
apac
ito
rM
ake
sure
the
rem
aini
ng fl
ying
lead
has
co
ntin
uity
to
eyel
ets
38 a
nd 4
1 . S
old
er
this
lea
d i
n t
o th
e “O
” lu
g o
f th
e fil
ter
cap
alo
ng w
ith t
he r
esis
tor
lead
alre
ady
in p
lace
.
Sold
er th
e le
ad fr
om h
ole
71 to
lug
“U” o
f th
e fil
ter c
ap a
long
with
the
resi
stor
lead
al
read
y in
pla
ce . T
his
lead
sho
uld
hav
e co
ntin
uity
to e
yele
t 1 .
Sold
er t
he le
ad f
rom
hol
e 72
to
lug
“X”
of t
he fi
lter
cap
alo
ng w
ith
the
resi
stor
le
ad a
lread
y in
pla
ce . T
his
shou
ld h
ave
cont
inui
ty to
eye
let 2
2 .
Sold
er th
e le
ad fr
om h
ole
74 to
lug
“Y” o
f th
e fil
ter c
ap a
long
with
the
resi
stor
lead
al
read
y in
pla
ce . T
his
lead
sho
uld
hav
e co
ntin
uity
to e
yele
t 54 .
S
TE
P 1
07
Sold
er t
wo
red
lead
sTr
im t
he
red
ou
tpu
t tr
ansf
orm
er l
ead
com
ing
th
rou
gh
th
e ru
bb
er g
rom
met
b
esid
e th
e fil
ter
cap
to
an a
pp
rop
riat
e le
ngth
and
sol
der
it to
eye
let 5
4 .
Als
o tr
im t
he r
ed l
ead
fro
m t
he r
ever
b
driv
er a
nd s
old
er it
to e
yele
t 63 .
S
TE
P 1
08
Sold
er t
hre
e ju
mp
ers
Sold
er th
e gr
een
jum
per
from
bia
s boa
rd
eyel
et E
to th
e fr
ont g
roun
ding
str
ip .
Als
o so
lder
the
gree
n ju
mp
er fr
om e
yele
t 6
to th
e fr
ont g
roun
ding
str
ip .
Sold
er t
he j
ump
er f
rom
hol
e 48
to
the
rig
ht
lug
of
the
exte
nsi
on
jac
k, a
lon
g w
ith th
e ju
mp
er fr
om th
e rig
ht lu
g of
the
spea
ker
jack
. Thi
s ju
mp
er s
hou
ld h
ave
cont
inui
ty to
eye
let 2
6 .
Sold
er th
e b
lue-
inke
d ju
mp
er fr
om h
ole
47 to
the
cent
er lu
g of
the
vib
rato
ped
al
jack
. Th
is s
ho
uld
hav
e co
nti
nu
ity
to
eyel
et 2
5 .
stew
mac
.co
m
38
©
2018
Ste
wM
ac
VIB
RAT
OPE
DA
LRE
VER
BPE
DA
LRE
VER
BO
UTP
UT
REV
ERB
INPU
TSP
EAK
ERPO
WER
GRO
UN
DFU
SEEX
TEN
SIO
N
PILO
TLA
MP
V7
5AR4
V6
6V6
V5
6V6
V4
12A
X7
V3
12A
X7
V2
12AT
7V
112
AX
7
INTE
NSI
TYSP
EED
REV
ERB
BA
SSTR
EBLE
VO
LUM
EIN
STRU
MEN
TS
21
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
OU
X
Y
O
–
U
X
Y
15
34
2
10
59
2017
67
89
11
5857
5655
5460
6162
6364
6568
6970
71 72 73 7466
67
1213
1415
1618
1921
2425
2627
3029
2831
2223
3233
3435
3740
4142
4344
4546
4748
4950
5152
5338
3936
AB
CD
FE
Keep
the
heat
er w
ires
upan
d aw
ay fr
om th
e so
cket
s
stew
mac
.co
m
39
©
2018
Ste
wM
ac
How to
REDU
CE TH
E HUM
cause
d by A
C volta
geTh
ese
gree
n he
ater
wire
s ca
rry
AC
vol
tage
that
will
cau
se h
um if
they
get
to
o cl
ose
to w
ires
that
car
ry th
e si
gnal
. The
se ti
ps
min
imiz
e th
at h
um .
Twis
t th
e w
ires
tig
htl
yTh
is r
educ
es h
um, i
n m
uch
the
sam
e th
e w
ay t
hat
two
opp
osit
e-w
ound
coi
ls w
ork
in a
hum
buc
king
pic
kup .
Ro
ute
th
em u
p a
nd
aw
ayLe
t the
se w
ires s
tick
up a
bou
t an
inch
from
the
sock
et b
efor
e b
endi
ng th
em . T
his k
eeps
the
hea
ter
wir
es f
rom
min
glin
g w
ith th
e si
gnal
wire
s .
Inst
all t
he
hea
ter
wir
esRe
view
thes
e st
eps
very
car
eful
ly b
efor
e yo
u st
art
inst
allin
g th
e he
ater
wire
s th
at
pow
er th
e he
atin
g fil
amen
ts in
the
tub
es .
It’s
imp
orta
nt to
twis
t the
se w
ires
tight
ly
toge
ther
. Thi
s is
n’t f
or lo
oks;
twis
ting
the
wire
s has
a h
um-c
ance
lling
func
tion
that
re
duce
s no
ise
in th
e am
p .
S
TE
P 1
09
Inst
all t
wo
12
" g
reen
jum
per
s
Cu
t tw
o 1
2" g
reen
ju
mp
ers
and
tw
ist
them
toge
ther
, lea
ving
ab
out
an in
ch o
f un
twis
ted
wire
on
each
sid
e . W
rap
thes
e w
ires
on
to t
he
lug
s o
f th
e p
ilot
lam
p .
Sold
er th
em in
pla
ce w
ith th
e tw
o 10
0Ω
resi
stor
s and
the
gree
n p
ower
tran
sfor
m-
er le
ads .
Rout
e th
ese
twis
ted
jum
per
s ar
ound
the
edge
of t
he c
hass
is to
reac
h so
cket
V6 .
S
TE
P 1
10
Ad
d t
wo
4"
gre
en ju
mp
ers
Cut
two
4" g
reen
jum
per
s . M
ark
one
of
thes
e ju
mp
ers
at b
oth
ends
with
a b
lack
m
arke
r so
you
can
tel
l the
m a
par
t af
ter
twis
ting
them
. Tw
ist t
hem
toge
ther
ver
y ti
gh
tly,
lea
vin
g a
bo
ut
an i
nch
fre
e at
ea
ch e
nd .
Con
nect
the
se ju
mp
ers
to t
he ju
mp
ers
from
the
pilo
t lam
p b
y tw
istin
g th
e en
ds
toge
ther
. Sol
der
the
pai
r with
the
bla
ck-
mar
ked
wire
to p
in 7
of s
ocke
t V6 .
Sold
er t
he u
nmar
ked
pai
r on
to p
in 2
of
sock
et V
6 .
Bend
thes
e w
ires s
o th
ey st
ick
stra
ight
out
fr
om th
e so
cket
by
1" a
s d
escr
ibed
in th
e hu
m-r
educ
ing
tips e
xpla
ined
at l
eft .
Bend
th
em in
to a
shar
p an
gle
tow
ard
sock
et V
5 .
S
TE
P 1
11
Ad
d a
no
ther
tw
o 4
" g
reen
jum
per
s
Cut t
wo
mor
e 4"
gre
en ju
mp
ers a
nd tw
ist
them
tigh
tly
toge
ther
.
Conn
ect t
he e
nds o
f the
se ju
mp
ers t
o th
e on
es c
omin
g fr
om s
ocke
t V6
. Sol
der
the
p
air w
ith th
e b
lack
-mar
ked
wire
to p
in 7
of
soc
ket V
5 .
Sold
er t
he u
nmar
ked
pai
r on
to p
in 2
of
sock
et V
5 .
Bend
the
se w
ires
so
they
sti
ck s
trai
ght
out
from
the
soc
ket
by 1
" as
des
crib
ed
bef
ore
. Ben
d t
hem
int
o a
sh
arp
an
gle
to
war
d so
cket
V4 .
S
TE
P 1
12
Ad
d t
wo
5"
gre
en ju
mp
ers
Cut t
wo
5" g
reen
jum
per
s and
twis
t the
m
toge
ther
tigh
tly .
For
the
rem
aini
ng tu
be
sock
ets,
you
no
long
er h
ave
to m
ark
the
wir
es o
r ke
ep t
rack
of
wh
ich
is
wh
ich;
th
ey’re
int
erch
ang
eab
le f
rom
her
e on
. C
onne
ct t
hese
new
jum
per
s to
the
pai
r co
min
g fr
om s
ocke
t V5 .
4 3
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t th
e en
ds
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eth
er
stew
mac
.co
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©
2018
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wM
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Ste
wM
ac
S
TE
P 1
13
Co
nn
ect
to s
ock
et V
4O
n t
he
rem
ain
ing
sm
all
tub
e so
cket
s,
twis
t p
ins
4 an
d 5
tow
ard
each
oth
er s
o th
eir h
oles
line
up .
Be
very
car
eful
whi
le
doi
ng th
is a
s th
ese
pin
s ar
e d
elic
ate .
Sold
er o
ne p
air o
f tw
iste
d w
ires
to p
ins
4 an
d 5
of so
cket
V4 .
Sol
der t
he o
ther
pai
r to
pin
9 o
f the
sam
e so
cket
. Trim
the
exce
ss
wire
s . B
end
thes
e w
ires a
s bef
ore,
rout
ing
them
tow
ard
sock
et V
3 .
S
TE
P 1
14
Ad
d t
wo
5"
gre
en ju
mp
ers
Cut
tw
o 5"
gre
en j
ump
ers .
Tw
ist
them
ve
ry ti
ghtl
y an
d jo
in th
em to
the
twis
ted
pai
r com
ing
from
soc
ket V
4 .
Sold
er o
ne p
air t
o p
ins
4 an
d 5
of s
ocke
t V
3, a
nd
so
lder
th
e ot
her
pai
r to
pin
9
of s
ock
et V
3 . B
end
th
ese
wir
es t
owar
d so
cket
V2 .
S
TE
P 1
15
Ad
d a
no
ther
tw
o 5
" g
reen
jum
per
s C
ut t
wo
mor
e 5"
gre
en j
ump
ers .
Tw
ist
them
ver
y tig
htly
and
join
the
m t
o th
e tw
iste
d p
air c
omin
g fr
om s
ocke
t V3 .
Sold
er o
ne p
air t
o p
ins
4 an
d 5
of s
ocke
t V
2, a
nd
so
lder
th
e ot
her
pai
r to
pin
9
of s
ocke
t V
2 . B
end
the
se w
ires
tow
ard
sock
et V
1 .
Sold
er o
ne o
f the
se w
ires
to p
ins
4 an
d 5
of s
ocke
t V1,
and
sol
der
the
othe
r wire
to
pin
9 o
f soc
ket V
1 .
S
TE
P 1
16
Ad
d t
he
po
wer
co
rd +
str
ain
rel
ief
Stri
p 8
-1/2
" o
f th
e p
ower
co
rd’s
ou
ter
insu
lati
on b
ack
so t
he b
lack
and
whi
te
lead
s ca
n re
ach
from
the
acc
ess
hole
to
the
pow
er s
witc
h an
d fu
se . T
wis
t th
ese
bla
ck a
nd w
hite
lead
s to
geth
er .
Cut t
he g
reen
lead
from
the
pow
er c
ord
to re
ach
the
rear
gro
undi
ng s
trip
. Tin
this
le
ad w
ith
so
lder
an
d w
rap
it
ont
o th
e m
iddl
e lu
g of
the
grou
ndin
g st
rip .
Pull
the
pow
er c
ord
lea
ds
thro
ugh
the
hole
in t
he c
hass
is a
nd s
ecur
e w
ith t
he
bla
ck s
trai
n re
lief .
The
stra
in re
lief i
s a
tight
fit .
Use
plie
rs to
sq
ueez
e it
onto
the
pow
er c
ord
outs
ide
the
chas
sis,
and
kee
p s
quee
zing
to
fit it
in
to th
e m
ount
ing
hole
.
Ru
n t
he
bla
ck a
nd
wh
ite
po
wer
co
rd
wire
s al
ong
the
bac
k w
all o
f the
cha
ssis
. So
lder
the
whi
te w
ire to
the
right
lug
on
the
pow
er s
witc
h .
Sold
er th
e p
ower
cor
d’s
bla
ck w
ire to
the
cent
er/b
ack
lug
of th
e fu
se s
ocke
t .
Dan
ger
: Sol
der
ing
this
lead
to
the
sid
e lu
g of
the
fuse
soc
ket w
ill c
reat
e a
shoc
k ha
zard
.
Sold
er t
he
pow
er c
ord
’s g
reen
gro
und
wire
to th
e ce
nter
lug
of th
e re
ar te
rmin
al
strip
(thi
s lu
g is
gro
und
ed to
the
chas
sis)
.
Take
a b
reak
, th
en r
evie
wN
ow t
hat
you’
ve s
old
ered
the
wire
s an
d co
mp
onen
ts, t
ake
a br
eak .
Com
e ba
ck in
a
bit
to c
heck
you
r wor
k b
efor
e co
ntin
uing
.
Ch
eck
you
r w
ork
slo
wly
an
d c
aref
ull
y.
You
’ve
com
ple
ted
we
ll o
ver
on
e h
un
dre
d s
tep
s so
far
, so
a fe
w s
mal
l er
rors
will
be
no
surp
rise
at a
ll . F
indi
ng a
nd fi
tho
se
erro
rs is
the
way
to h
ave
your
am
p w
ork
succ
essf
ully
whe
n yo
u ge
t to
the
test
ing
and
pow
er u
p s
tage
!
SLOW
stewmac.com 42 © 2018 StewMac
STEP 117
Install the fuseInsert the 1-amp fuse into the fuse socket from the back of the chassis . Make sure the socket cap is secure . Never use a fuse rated above 1 amp in this amplifier .
Installing the fuse, lamp, and knobs
STEP 118
Install the pilot lampInsert the pilot lamp bulb into its sock-et from the front of the chassis and twist until it locks back in place . Screw the red jewel lens over the socket .
STEP 119
Install the six control knobsTurn the shaft of each pot all the way counterclockwise to the “off” point and install the knob so the indicator line points to number 1 .
STOP!
Set the chassis on blocksSet your chassis up for final testing . A chassis stand is a great thing to have for this, because it holds the work at any angle . If you don’t have one, a couple of blocks of wood will get you by just fine .
DON’T INSTALL THE TUBES YET! DON’T PLUG THE AMP IN YET!
The next page will keep you out of trouble!
stewmac.com 43 © 2018 StewMac
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 mak-ing sure current flows 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 120
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 in-dication 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 imme-diately and carefully review all your connections .
STEP 121
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, unplug the amp and check your connections .
If the amp seems normal, unplug the power cord while still leaving the power switch ON .
STEP 122
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, in-stall the 5AR4 rectifier tube while spreading the tension clip with the other hand . Take care to position the indexing key correctly in the socket .
Plug the power cord back in . The pilot lamp should light, along with the fil-ament inside the 5AR4 rectifier tube .
Again, spend a few minutes watching for smoke or smells .
At this point, dangerous voltage is forming in the filter caps. Always discharge them before working on the circuit, even if the amp is unplugged. See how to use a snuffer stick on page 6 .
For safety, use only one hand to touch the amp during DC tests. Keep your other hand behind your back when you need to probe a com-ponent . This way, 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 500V DC and connect the negative lead to ground . Once the negative lead is secured to ground, measure the DC voltage at eyelet 54 for your B+ voltage . This should be roughly 420V DC .
Testing and troubleshooting
6
4 32
1
987
5
54
71
72
73
74
22O U
X
Y
Gro
un
dALWAYS 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 44 © 2018 StewMac
Unplug the ampDanger: Remember to discharge the capacitors before working on the circuit . See how to use a snuffer stick on page 6 .
STEP 123
Test the preamp tubesWith the amp unplugged, you can install the four preamp tubes . When these tubes are installed, plug the amp back in . The pilot lamp should light up .
Let the amp warm up for a few min-utes . Again, if you get smoke or smells, unplug immediately and review your connections .
Connect your multimeter’s negative lead to ground .
Set your multimeter to 5V DC and check eyelet 70, which should read around 1 .3V .
Set the multimeter to 200V DC and check eyelet 68, this should give a reading of about 160V .
If these voltages read within about 10% of their expected values, unplug the amp .
If the reading at eyelet 68 shows no voltage or low voltage, follow this test: unplug the amp and drain the filter caps with the snuffer stick . Set your meter to read continuity . Check to see that you have properly installed the flying jumper from the “O" lug of the filter cap to eyelet 41 . You should have continuity between these two points .
STEP 124
Test the 6V6 power tubesWith the amp unplugged, install the 6V6 power tubes in sockets V5 and V6 . They have an indexing key on the center post to guide them correctly into the socket .
Plug in the speaker, footswitch, and reverb tank .
Perform these next tests with the speaker turned away from you . This is to protect your ears in case the amp starts to oscillate and squeal .
Plug the amp in . After a few moments you should hear a low hum . If the hum becomes very loud, disconnect the power immediately and review your connections .
After the amp has warmed up for a few minutes attach your multimeter’s negative lead to ground, such as the metal chassis or a grounding strip .
Set your multimeter to read 5V DC and test for voltage at eyelet 70 . This voltage should read around 1 .3V .
Set your multimeter to read 500V DC and test for voltage at pin 3 of the V6 6V6 socket . This voltage should read around 370V .
Set your multimeter to read 50V DC and test for voltage at eyelet 24 . This voltage should read around -29V (negative 29V) .
If your voltage readings are correct, plug a guitar in and play at low vol-ume . If the amp behaves as it should, keep increasing the volume . It should start to break up nicely as you increase the volume .
STEP 125
Test the reverb and tremoloIf the reverb doesn’t seem to work, try switching the cables in the reverb input and output 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 adjustment like resoldering a loose joint to correct this sort of distortion .
After testing all inputs, if everything seems to be operating normally, turn the amp off . You’re ready to assemble it and play it!
stewmac.com 45 © 2018 StewMac
STEP 127
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!Tips for using this ampThis amp is known for its gorgeous clean tones and luscious reverb . The vibrato isn’t as deep as is typical on Fenders because it’s tube-driven, not optocoupler-driven .
The amp’s cathodyne phase inverter creates “brown” distortion when you really start to drive the power tubes . This overdrive really pushes the mids and lows, and can become flabby if you don’t have your settings right . Use the Bass and Treble controls to dial this in . With humbuckers, try turning the bass down a bit . Give singlecoils a little more bass .
With singlecoils you can also push the reverb a little higher, which would make humbuckers become muddy .
The ’65 P-Reverb is a great pedal platform, especially for modulation and delay . Fuzz pedals will most likely need a mids-booster such as an over-drive to keep your tone from being lost in the mix, because fuzz pedals typically cut mids drastically .
Overdrive pedals on their own are great to kick in when you want to jump to the front of the mix .
Still, my favorite way to play this amp is to plug straight in and go . This amp is a classic because it has everything you need for that clean Americana tone and that drenched surfy jangle, all in one box .
Matt Clouston, StewMac
GO!GO! 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 kit, and welcome to the world of amp building!
Final assembly
stewmac.com 46 © 2018 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 . This 3-part component is called a triode .
The V1 preamp tube is the only true preamp gain stage in this circuit . A relatively cold bias, with a 1 .5K cath-ode resistor for each side, keeps the headroom high and reduces preamp distortion .
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 doing this, because it places unneeded stress on the output transformer .
The processing stage shapes the tone . The smallest amp of the black-panel era with both reverb and vibrato, most of the P-Reverb’s preamp tubes handle both driving and recovery of these effects . Preamp tube V2 sends the signal to the reverb, and V3 recov-ers that signal and mixes the dry and wet signals .
The first half of V4 drives the vibrato, the second half is the phase inverter . This is very different from the larger black-panel era amps, and can result in a more “brown” distortion .
The sensitive bass response can over-whelm the 10" speaker, so you might want the treble controls a little bit higher than the bass controls .
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 cap, which contains four 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 is cathode biased, which means you don’t need to make any adjustments when replacing the power tubes . Just make sure you are replacing the power tubes with a matched pair .
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 47 © 2018 StewMac
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stewmac.com 48 © 2018 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 / 10” 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 49 © 2018 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 1962 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 1965 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 1981 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 50 © 2018 StewMac
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stewmac.com 51 © 2018 StewMac
’65 P-REVERB 15WO R I G I N A L AA1 1 64 C I R C U I T
StewMac®
I C O N K I T S
Use only 1-amp slow-blow fuse.
DANGER: Unplug the amp before changing tubes.Tube locations from left to right:
5AR4(GZ34)
6V6 6V612AT7(ECC81)
12AX7(ECC83)
V7 V6 V5 V2 V1
12AX7(ECC83)
12AX7(ECC83)
V4 V3
#10734
’65 P-REVERB 15WO R I G I N A L AA1 1 64 C I R C U I T
StewMac®
I C O N K I T S
Use only 1-amp slow-blow fuse.
DANGER: Unplug the amp before changing tubes.Tube locations from left to right:
5AR4(GZ34)
6V6 6V612AT7(ECC81)
12AX7(ECC83)
V7 V6 V5 V2 V1
12AX7(ECC83)
12AX7(ECC83)
V4 V3
#10734
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 52 © 2018 StewMac
stewmac.com 53 © 2018 StewMac
tools + ideas for guitarmakingStewMac
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©2018 StewMac . All rights reserved .#i10734 Updated October, 2018