TubeDepot Tweed 5F1 User manual

Assembly Manual
Tweed 5F1
Instructions for Assembling with the:
-Printed Circuit Board (PCB)
with additional modification suggestions and recommended amp settings
version 17.0
May 24, 2017
Learn Build Play

This manual was developed and published by:
TubeDepot.com
Memphis, TN
Written by:
Robert Hull
Edited by:
Mary Klaebel JP Phelps
Design and artwork by:
Robert Hull
Mary Klaebel
Christian Magee
Acknowledgements:
Special thanks to:
Joe Austin Mitchell Bird Rees Shad
Caleb Kim Matt Kirby
Henry Lum Joe Moffett
Brian Overstreet Ben Siler
Doug Sims John Puffer
Rex Cuizon
Copyright © 2009
TubeDepot.com
1958 Vanderhorn Drive
Memphis, TN 38134
[phone]
[email protected]
REGARDING THESE BOOK MATERIALS
Reproduction, publication, or duplication of this booklet, or any part thereof, in any manner, mechanically,
electronically, or photographically is prohibited without the express written permission of the publisher.
The Author, Publisher or Seller assume no liability with respect to the use of the information contained herein.
For permission and other rights under this copyright, contact TubeDepot.com.
ii TubeDepot.com

page
Preface and Tweed 5F1 overview ....................................................................................... iv
Chapter 1
Safety ….........................................................................................................................1
Chapter 2
Tools and Supplies ….....................................................................................................2
Chapter 3
Parts Inventory ...........................…................................................................................3
Chapter 4
Cabinet Preparation …....................................................................................................4
Chapter 5
Circuit Assembly (PCB)…...............................................................................................5
Chapter 6
Chassis Preparation and Assembly …..........................................................................10
Chapter 7
Final Assembly …...........................................................................................................9
Chapter 8
Testing …......................................................................................................................20
Chapter 9
Schematics and Parts Layout …...................................................................................23
Chapter 10
Cool Modifications …....................................................................................................28
Appendix
A. How to Read Resistor and Capacitor Codes ….......................................................29
B. Soldering Hints ….....................................................................................................32
C. Amplifier Care, Feeding, and Application Hints …...................................................34
D. Drilling Templates …................................................................................................36
Table of Contents
TubeDepot.com iii

Short History of the Tweed Fender Champ
With just 4 watts, the first incarnation of the Fender Champ was introduced in 1948 and
was called the “Champion 800”. It had one 6SJ7 preamp tube, a single 6V6 power tube, and
a 5Y3 rectifier tube. Along with an 8” speaker, it was covered in two toned brown and tan vinyl
and was beautiful to behold. In 1953 the name changed to “Champion 600 ” with a 6”
speaker replacing the original 8”. The two toned vinyl remains, however some of the later
Champion 600's are covered in the new transition tweed covering. By 1953, all Champion
amps were covered in tweed and all still sounded great! These early Champions were the
perfect complement to the new Telecaster family of guitars. But all is not finished yet …
The biggest improvements were brewing. In 1955, the “Champ” is born with the introduction
of the new 12AX7A as the preamplifier tube (replacing the 6SJ7). This brings the output to 5
watts into a 6” speaker. But there is one more big improvement coming. In 1958, along with a
slight component change, the 8” speaker is reintroduced. With this final change, the “mother
of tone” is born. It is as if the planets aligned and whispered to Leo Fender what the near
perfect amp should sound like. He was listening because here it is.
It is this last, near perfect incarnation that we provide for you here.
The tweed champ is one of my favorite amps. Inside its diminutive size rests the heart of an
entire world of music. From blues, to rock-a-billy; from rock-n-roll to soul; from country to jazz,
this amp is capable of holding its own across a wide swath of musical history and genres.
From humble consideration as a “beginner amp”, this amp has become a standard bearer for
what is cool about music.
Therefore imagine my excitement in designing a kit where you can build an incredible amp
on which to put your musical mark on the world. Wow … this is going to be fun!
Thank you for purchasing this great kit. You should be able to easily put this kit together in
an evening or two … whether you have any prior amp building experience or not. I designed
this kit for you to enjoy both building and playing this amp. And once finished, this kit will allow
you to make the best music you can … to make your world mark.
Now, let's have some building and playing fun.
Robert Hull
Director of Technical Services
TubeDepot.com
“Champ” and “Fender” are the property of Fender Musical Instruments Corporation (FMIC). TubeDepot is not
affiliated or associated with FMIC or its subsidiaries and FMIC does not sponsor or endorse any of TubeDepot’s
products.
Preface
TM
TM
TM
TM
iv TubeDepot.com

!!! Read these safety precautions before continuing !!!
ALL tube amplifiers contain LETHAL VOLTAGES, often several hundred volts which WILL
leave burnt entrance and exit wounds in skin. These voltages have the potential to cause
permanent physical damage and death. These voltages are present when the amp is
turned on and also for some time after the amp has been turned off. You can still get
shocked with a tube amp turned off and disconnected from AC power.
The above statement is a bit scary, but we want to stress that every piece of electronic
equipment must be treated with respect. When AC power is applied, there is always a chance
for injury or death. With tube amps, even when the AC power is not applied there is still
danger. Being shocked with high voltage is very painful and we do not want anyone finding
out the hard way.
When building this kit, we want your experiences to be both enjoyable and safe. There are
more kits to assemble and we want you to enjoy building and playing them all.
Throughout this manual at key points in the construction, we have annotated important
steps with the below alerts. For your safety and to improve construction quality, It is important
that you become familiar with each of these alerts and adhere to their recommendations when
they appear.
Explanation of Alerts
1
Safety
- DISCLAIMER -
TubeDepot.com, its employees, officers, shareholders, investors and
subsidiaries accept no liability for any damage(s), injury(s) or death incurred from
or while building or using this kit.
TubeDepot.com reserves the right to make changes to this manual as new
construction methods are fo
und to be more efficient and/or safer. When a
particular procedure in this assembly manual differs from the assembly video, our
recommendation is to follow this manual to insure the best construction possible.
-Used when identifying an action that may cause physical injury or death.
WARNING
-Used when identifying an action that may cause damage to components
and/or equipment.
CAUTION
NOTE
-Used when identifying general points of interest.
TubeDepot.com 1

As with any construction project, there are certain tools and supplies that are recommended
to complete the project. These are tools and supplies not provided with the kit and are instead
provided by the builder. TubeDepot.com
The following is our recommended list: part number
Phillips screwdriver, #1 and #2 TL-VTSCRSET8
Slip joint pliers
Needle nose pliers TL-VT33
Wire cutters, diagonal TL-VT33
Wire strippers, for 18 and 20 awg wire TL-VT5021
Electric Drill
Drill bit, 3/16” - Chassis mounting in the cabinet
Drill bit, 5/32” - PCB and turret board chassis mounting
Drill bit, 1/8” - Fiberboard mounting
Masking tape, 2”
Ruler or scale, 12” w/ 1/16” markings
Permanent marker, fine tip
Soldering iron, 25W – 40W (35W recommended) TL-WP35
Solder, electronics safe (60/40 w/ rosin core recommended) TS-24-6040-0027
Flux, electronic – liquid or paste (must be safe for electronic work) TS-83-1000-0186
De-soldering pump extractor TS-384-1000
Solder wick TS-1817-10F
Sponge
The following are really nice to have:
Soldering station w/ temperature control TL-WTCPT
Multimeter w/ DC range of at least 500V TL-DVM850BL
Variable AC supply (Variac® style)
Current Limiting AC source (build directions in this manual)
Needle nose pliers – small size, for electronics work TL-NN7776
Wire cutters, diagonal – small size, for electronics work TL-170M
Center punch
Nutdrivers - 5/16”, 11/32”, 7/16”, 1/2”
Square, 9”
Scratch Awl
heat shrink, 1/8” x 6” TS-HS-ASST-7
De-burring tool
Fingernail polish (for holding nuts and screws in place)
2
Tools and Supplies
2 TubeDepot.com

It is important to review all the parts that came with your kit. The list below is what you
should have received to complete your kit. If you find anything missing, contact us:
Qty Description Application
1 speaker, 8" Jensen MOD, 8 Ω (4 Ω available) speaker
1 chassis, steel chrome plated 5E1/5F1 chassis
1 cabinet, tweed 5E1/5F1 cabinet
1 PCB board, 5E1/5F1 _ printed circuit board
transformers
1 transformer, ClassicTone 40-18027 power transformer
1 transformer, output tweed 5F1 4 & 8 ohm tap output transformer
tubes
1 5Y3 rectifier tube rectifier tube
1 6V6GT beam power tetrode power tube
1 12AX7 dual triode _ preamp tube
panel hardware
1 knob, vintage pointer knob
1 fuse holder, conical cap, vintage Fender style fuse holder
1 fuse, 3AG 2A slow-blow fuse
1 lamp holder lamp holder
1 jewel, red lamp jewel
1 lamp, #47, 6.3 V lamp
2 jack, 12A, shorting, Switchcraft ¼" input jack
1 jack, 11A, open, Switchcraft ¼" speaker jack
3 washer, lock 3/8" jack lock washer
1 plug, Switchcraft ¼" speaker plug
power cord hardware
1 power cord, grounded three prong, 12' power cord
1 strain relief, Heyco power cord strain relief
1 nylon cable clamp power cord clamp
1 screw, zinc plated #8 x 5/8", phillips flat head cord clamp mounting
tube sockets
1 socket, tube, miniature 9pin preamp tube
2 socket, tube, octal rectifier / power tube
hardware
2 grommets, rubber 3/8" hole grommets
2 bolt, 1 1/2" 10x32 truss screw chassis mounting
2 nuts, KEPS 10x32 chassis mounting
6 screw, zinc plated 6-32 x 1/4", phillips pan head tube socket mounting
9 nuts, KEPS 6x32 tube socket / PCB mounting
1 nuts, 6x32 tube socket w/ solder tab mounting
4 nuts, KEPS 8x32 power / output transformer mounting
2 nuts, 8x32 power transformer w/ solder tab mounting
4 screw, zinc plated 6-32 x 7/8" phillips pan head PCB mounting
4 standoff, nylon; L = .5"; id = .140"; od = .250" PCB mounting
2 screw, zinc plated 8-32 x 1/4", phillips pan head output transformer mounting
2 solder lug, locking, #8 screw grounding at power transformer
1 solder lug, locking, #6 screw grounding at preamp tube socket
1 wire nut power cord to power transformer wiring
electronic, resistors
2 100, 1/2w carbon film filament pseudo center tap
2 68K, 1/2w carbon film input resistors
1 1M, 1/2w carbon film _ input biasing resistor
2 100K, 1/2w carbon film preamp tube plate resistors
TubeDepot.com 3
Parts Inventory
3
TubeDepot.com
1958 Vanderhorn Dr.
Memphis, TN 38134
[phone]
[email protected]

2 1.5K, 1/2w carbon film preamp tube cathode resistors
1 22K, 1/2w carbon film feedback resistor
1 220K, 1/2w carbon film biasing resistor
1 470, 3w metal oxide cathode resistor
1 10K, 2w metal oxide B+ resistor
1 22K, 1w metal oxide B+ resistor
electronic, capacitors
2 .022ufd / 630v coupling caps
2 22ufd / 50V cathode bypass caps
1 22ufd / 500V power supply filter cap
2 10ufd / 450V power supply filter caps
electronic, potentiometers
1 1M pot w/ on-off switch (Alpha ) volume / power switch
1 100K trim pot, horizontal mount feedback adjustment
wire
3' wire, 20 awg, stranded, hi-temp PVC – yellow board, general wiring
2' wire, 20 awg, stranded, hi-temp PVC – red board, signal / B+ wiring
2' wire, 20 awg, stranded, hi-temp PVC – black board, ground wiring
3' wire, 18 awg, stranded, hi-temp PVC – green filament wire
2' wire, 18 awg, stranded, hi-temp PVC – black speaker wire, -
2' wire, 18 awg, stranded, hi-temp PVC – white speaker wire, +
shielding
3” aluminum tape, 3" width, 10” length, self adhesive electrical and heat shielding
heat shrink
1 heat shrink, 1/4" - black, 6" piece wire dressing / capping
4 TubeDepot.com

This chapter deals with preparing the cabinet for installation of the completed chassis. But
first, we need to take inventory of the parts that came installed on the cabinet.
1. Handle w/ mounting hardware – There should be a single flat brown leather handle
with two metal securing ends all fastened to the cabinet with four screws.
2. Feet, chrome metal glide – There should be four metal feet attached with screws to
the underside of the cabinet.
3. Back panels, upper and lower with screws – There
should be two back panels. The top back panel should be
secured with four panel screws, the bottom panel should
be secured with two panel screws.
4. Baffle bolts with nuts – There should be four bronze
plated bolts attaching the baffle to the cabinet. The baffle
is secured with four KEPS nuts, one on each of these
bolts.
5. Speaker bolts with nuts – There should be four black
bolts exiting from the baffle board. There should be four
KEPS nuts (one on each of these black bolts) used for
mounting the speaker.
Drilling for the Two Chassis Mounting Bolts
Step 1 – Remove the amp handle from the top of cabinet
Step 2 – Remove the top back panel (place a small mark on the
inside of the panel to indicate which edge is up)
Step 3 – Apply masking tape on each side of cabinet opening (photo 4.1a).
Step 4 – Download and print the correct sized cabinet drilling template from our website:
http://site.tubedepot.com/pdf/5F1_cabinet_drilling_template.pdf
Step 5 – Fold the correctly sized template at indicated line and place template flat on top of
cabinet, properly centered over the opening (photo 4.1b).
Step 6 – With a pointed tool, make a mark through the template at
the cross hair points marked “drill 3/16” (photo 4.1c). Press lightly
into the tape and cabinet. This doesn't have to be a deep mark, just
enough to see the mark on the masking tape underneath.
Step 7 – Remove the template. With a ruler or scale, check and
verify that the marks are properly aligned on the cabinet top as
referenced to the measurements on the template.
Step 8 – If the marks are verified correct, drill the two 3/16” holes,
one at each of these two marks all the way through the top of the
tweed cabinet.
TubeDepot.com 5
4
Cabinet Preparation
photo 4.1a
4.1
photo 4.1b
Some printers may automatically reduce the size of the template when printed.
Therefore, prior to use, always physically measure the printed template to insure proper
scale is maintained.
CAUTION
The cabinet drilling template should be aligned to the cabinet's very edge. Verify correct
template placement before drilling. Do NOT bend the template to follow the curved edge.
Always measure several times before drilling.
CAUTION
photo 4.1c
photo 4.1c

Step 9 – Remove the masking tape and clean up any loose
material from the holes and test fit the chassis mounting bolts.
Step 10 – With the chassis mounting bolts in the cabinet, test
fit the chassis onto the bolts
Step 11 – Remove chassis and reinstall handle, leaving chassis mounting bolts installed.
Proceed to 4.2
Installing the Speaker
Step 1 – Remove the four nuts from the speaker mounting bolts inside the cabinet.
Step 2 – Remove the speaker from its shipping box. With speaker in hand, carefully align the
speaker mounting holes to the baffle bolts. I recommend installing the speaker with
connecting terminals on top.
Step 3 – Slowly press the speaker onto these bolts, being certain that the bolts are
proceeding through the mounting holes of the speaker equally (photos 4.2a, b, & c).
Step 4 – Once the speaker is installed on the bolts,
install and tighten the KEPS nuts.
Proceed to steps 4.3
Wiring the Speaker
Step 1 – Twist the two lengths of black and white wire together (photo 4.3a).
Step 2 – At one end, strip the insulation back ½ ” from both wires and tin these two wires
(photo 4.3b).
Step 3 – Unscrew the barrel of the ¼ ” phone plug.
Step 4 – Solder the two tinned wires to the plug; white
to center and black to shield (photo 4.3c). Reinstall
plug barrel.
Step 5 – At opposite end of the twisted wire pair, strip the insulation ¼” and tin both wires.
6 TubeDepot.com
4.2
Alignment of all holes during speaker installation is very important. Otherwise, one or more
of the bolts may puncture the speaker cone by accident.
CAUTION
photo 4.2c
photo 4.2b
photo 4.2a
4.3
photo 4.3a
photo 4.3b
NOTE
The ¼” phone plug was invented for use
in telephone switchboards in 1878.
photo 4.3c
Although it is no longer used for telephone switching, this
great plug has become the standard connection type
between musical instruments and outboard equipment.

Step 6 – Solder these wires to the solder terminals of the
speaker; the white wire to the “+” terminal and the black wire to
the “-” terminal (photo 4.3e).
Proceed to 4.4
Installing the Shielding Tape
Step 1 – Place the removed back panel with the tweed side toward
the desk and the wood side facing up.
Step 2 – Cut the 30” aluminum shielding tape strip into three equal
lengths of 10”
Step 3 – Remove the backing from the first of the three shielding tape strips.
Step 4 – Apply the aluminum tape to the back of the
panel. Leave 1/8th of an inch space at the top of the
panel and centered the strip between the two panel
edges (photo 4.4a).
Step 5 – Remove the backing from the second
shielding tape strip and apply the tape to the back of
the panel similar to the first strip. Place it just below the
first strip, over lapping by 1/8th of an inch and centered
on the panel.
Step 6 – Remove the backing from the final shielding
tape strip and apply the tape to the back of the panel
similar to the previous two strips. Align the edge of the
tape along the bottom edge of the panel, offset by 1/8th
of an inch from the bottom edge of the panel and overlapping the second strip (photo 4.4b).
Proceed to chapter 5
TubeDepot.com 7
4.4
photo 4.3e
Once the backing is removed from the aluminum tape, the tape will have a tendency to curl.
Be sure to keep the tape straight to avoid having the tape stick permanently to itself.
CAUTION
photo 4.4a
photo 4.4b

Here is where good soldering skills and attention to detail will pay off. By following these
directions, you should be able to complete the circuit assembly quickly and without errors.
I encourage you to first read all the steps to familiarize yourself with not only the installation
flow, but also the components to be used. Appendix A has explanations on how to read the
value codes found on both the resistors and capacitors. Appendix B has helpful hints on
improving soldering skills.
Printed Circuit Board (PCB) Assembly
This PCB was designed to sound great and to maximize your customizing ability in a
compact, easy to assemble package. This PCB layout closely follows the original point-to-
point layout in order to duplicate any tone shaping created by component and wiring proximity
interactions. With over-sized traces and through-hole plating, this board will provide years of
trouble free life.
Step 1 – Gather all components necessary to complete the PCB. Separate the components
by type; the resistors in one pile, the capacitors in another, the trim pot a third. The resistors
will be installed first. They have no polarity and can therefore be installed in either direction.
Step 2 – Install a 1.5K / ½ watt resistor (brown, green, red, gold) in R6 position.
Step 3 – Install two 68K / ½ watt resistors (blue, gray, orange, gold) in positions R1 & R2.
Step 4 – Install two 100K / ½ watt resistors (brown, black, yellow, gold) in positions R4 & R5.
Step 5 – Install a 22K / ½ watt resistor (red, red, orange, gold) in position R8.
Step 6 – Install a 220K / ½ watt resistor (red, red, yellow, gold) in position R9.
Step 7 – Install a 1.5K / ½ watt resistor (brown, green, red, gold) in position R7.
Step 8 – Install a 470 / 3 watt resistor (yellow, violet, brown, gold) in position R10. The PC
board says 2 watt but I upgraded to a larger resistor.
Step 9 – Install a 22K / 1 watt resistor (red, red, orange, gold) in position R12.
Step 10 – Install a 10K / 2 watt resistor (brown, black, orange, gold) in position R11. The PC
board says 1 watt but I upgraded to a larger resistor.
Step 11 – Install a 22ufd/50V electrolytic capacitor in position C3. This
component has a polarity, therefore it must be installed according to case
and board markings (photo 5.1a).
Step 12 – Install a 22ufd/50V electrolytic capacitor in position C4. This
component has a polarity, therefore it must be installed according to case
and board markings.
Step 13 – Install the 100K trimmer pot (VR2, negative feedback adj.)
8 TubeDepot.com
5
Circuit Assembly
5.1
For great hints on improved soldering skills, review Appendix B at the end of this manual.
Additionally, visit:
http://www.youtube.com/user/TubeDepotTV and watch “How To Solder”.
NOTE
CAUTION
Electrolytic capacitors DO have a polarity and must be installed into the circuit according to
the markings on the component and the PC board.
NOTE
See “Cool Mods”, chapter 10 for description on how to use this
control
to fine tube this amp to your sound.
photo 5.1a

Step 14 – Install the two .022 ufd coupling capacitors in
positions C1 & C2. These capacitors do not have a polarity
and can be installed in either direction.
Step 15 – Install the two 10ufd / 450V electrolytic filter capacitors
in positions C8 & C7. These components have a polarity,
therefore they must be installed according to case and board
markings (photo 5.1b).
Step 16 –
Install the 22ufd / 500V filter capacitor in position C6. This component has a polarity,
therefore it must be installed according to case and board markings (photo 5.1b).
Proceed to 5.2
Installing the Wires to the Board
Black Wires (Grounding)
Step 1 - Strip back the insulation from the end of the
black wire 1/8” and tin the end of the exposed
strands. Insert the tinned end of this wire into the pad
labeled “G1a” and solder. Measure and cut this wire
to a length of 3” from pad G1a (photo 5.2a).
Step 2 – Repeat above for pad G2a & G2b.
Step 3 – Repeat above for pad G3a except extend to
4” length.
Step 4 – Repeat above for pad G4a (4” length).
Step 5 – Repeat above for pad G6a (3” length).
Red Wires (Circuit B+ and Preamp Tube Inputs)
Step 5 - Strip back the insulation from the end of the
red wire 1/8” and tin the end of the exposed strands.
Insert the tinned end of this wire into the pad labeled
“d” and solder. Measure and cut this wire to a length
of 3” from pad d.
Step 6 – Repeat above for pad e.
Step 7 – Repeat above for pad m.
Yellow Wires (General Signal Routing)
Step 8 - Strip back the insulation from the end of the
yellow wire 1/8” and tin the end of the exposed
strands. Insert the tinned end of this wire into the pad labeled “a” and solder. Measure and cut
this wire to a length of 3” from pad a.
Step 9 – Repeat above for pads b.
Step 10 – Repeat above for pad c except extend wire to 4”.
Step 11 – Repeat above for pads f through k.
Step 12 – Repeat above for pad n (photo 5.2a).
Proceed to Chapter 6
If using the 16ufd/475V Sprague Atoms in the C6
position, the positive end of the capacitor must be
mounted as close toward R11 as possible. In this way,
the negative end of the Sprague Atom 16ufd/475V cap
will clear the pilot lamp assembly without shorting out.
CAUTION
TubeDepot.com 9
photo 5.1b
5.2
photo 5.2a

Drilling Mounting Holes for the Printed Circuit Board (PCB)
Step 1 – Download and print the template “drilling template chassis/5F1” from:
http://site.tubedepot.com/pdf/5F1_chassis_drilling_template.pdf
Step 2 – Situate the chassis with the large
chrome side facing up and the printed control
panel facing toward you and place the template onto the chassis. Make sure the template markings
line up with the actual chassis cutouts.
Step 3 – On the template, locate the four concentric circular drill indicators (photo 6.1a).
Step 4 – With a sharp, hardened tool (center punch is great), make a mark at the center of these
drilling indicators, leaving an identifiable indentation / mark on the chassis (photo 6.1b).
Step 5 – Utilizing the printed measurements from the template, verify that these marks are correctly
situated on the chassis.
Step 6 – Once verified, drill four, 5/32” holes, one hole at each of these marked spots.
Step 7 – Remove any burrs around holes. A
deburring tool is very helpful here.
Proceed to 6.2
Installing the Power Transformer
Step 1 – Loosely twist all power transformer wires
together and slowly guide the wire bundle through
chassis opening. Twist both yellow wires together,
both red wires together, and both red and white
striped wires together. The brown and white striped wire gets twisted with black and white striped wire,
solid black gets twisted with solid brown.
Step 2 – Situate the transformer with the primary wires (black wires) nearest the fuse holder and the
secondary wires (reds, yellows, greens) nearest the rectifier tube socket.
Step 4– Install and tighten two #8 KEPS nuts on the transformer mounting bolts nearest the edge
side of the chassis (photo 6.2a).
Step 5 – Bend the two #8 solder tabs at a slight angle (photo 6.2b).
Step 6 – Install these tabs on the remaining two transformer bolts, oriented at angles toward the
chassis edges (photo 6.2a).
Step 7 – Install the two #8 standard nuts on these two bolts with the solder tabs (photo 6.2a).
Proceed to 6.3
6
Chassis Preparation
6.1
photo 6.1a
Some printers may automatically
reduce the size of the template
CAUTION
when printing. Therefore, prior to use, always
physically measure the printed template to insure
proper scale is maintained.
photo 6.1b
A sharp, large nail and hammer make a great make-shift center punch. By placing the nail
on the template mark and firmly tapping the head of the nail
with the hammer, the resultant
mark in the metal is great for accurately guiding the drill bit into the chassis.
NOTE
Use a new drill bit when drilling this chassis. Go slowly through the steel at a low rotational
speed. A little drop of light oil at
each drilling point helps too. These practices will allow the
metal to be cut cleanly with minimal formation of burrs.
NOTE
--- KEPS nuts ---
6.2
photo 6.2a
Photo 6.2b
10 TubeDepot.com

Installing the Rubber Grommets
Step 1 – locate the two rubber grommets and the two
corresponding holes on the chassis.
Step 2 – Insert the two rubber grommets in the
chassis holes (photos 6.3a and 6.3b).
Proceed to 6.4
Installing the Output Transformer
Step 1 – Twist the red, blue and brown primary wires together.
Step 2 – Twist the yellow, green, and black secondary wires together.
Step 3 – Feed the two wire sets into the grommets (photo 6.4a). The
red, blue, and brown wires go into the grommet nearest the power
transformer.
Step 4 – Pull the two wire bundles tightly through the grommets
leaving the transformer flush on the chassis.
Step 5 – Secure the output transformer to the chassis with two #8
KEPS nuts and the two #8 x 1/4” screws. The two KEPS nuts should
be mounted on the inside of the chassis.
Proceed to 6.5
Installing the Octal Tube Sockets
Step 1 – Prior to mounting, slightly bend the solder terminals on the back of the socket
outward (photo 6.5A).
Installing the 9 pin Tube Socket
Step 1 – Prior to mounting, slightly bend the solder terminals 1 - 3 and 6 –
9 on the back of the socket outward, leaving pins 4 and 5 alone for now.
Step 2 – Using a pair of needle nose pliers, carefully bend terminals 4 and
5 together. The holes of each of these terminals should meet flush
against each other (photo 6.6a).
TubeDepot.com 11
6.3
photo 6.3a
photo 6.3b
6.4
photo 6.4a
The new upgraded output transformer has an additional brown primary wire which is not
seen in the video or photos in this manual. This brown wire is NOT used in this build. We
recommend running this wire into the chassis
and sealing its end with insulation tape or
heatshrink. It will NOT be connected to anything.
NOTE
6.5
This photo does not show the
brown wire (see above note)
The terminals of these sockets will break if bent too far. It is recommended to use needle
nose pliers for better control when bending these terminals.
CAUTION
Pin 2 -----
Photo 6.5a
6.6
The terminals of these sockets will break if bent too far. It is
recommended to use the needle nose pliers for better control when
bending these terminals.
CAUTION
Photo 6.6a
Step 2 – Insert the socket from the outside of the chassis.
Rotate both sockets so that Pin 2 is closest to the chassis
edge.(photo 6.5b).
Step 3 – Secure the socket to the chassis with two #6 x
1/4” screws and two #6 KEPS nuts per socket.
Proceed to 6.6
Photo 6.5b
Pin 2 -----

Step 3 – To provide a flush mounting surface for the screws,
use a pair of needle nose pliers to carefully bend the edges of
the shield near the screw mounting holes in toward the socket
(photo 6.6b, 6.6c, and 6.6d).
Step 4 – Insert the tube socket from the
outside of the chassis and rotate the socket
so that pin 8 of the tube is closest to the
chassis edge (photo 6.6e).
Step 5 – With a #6 x 1/4” screw and #6
KEPS nut, secure the tube socket to the
chassis with the outside hole (photo 6.6e).
Step 6 – Now bend the #6 solder tabs at a
slight angle.
Step 7 – Insert a #6 x 1/4” screw into the remaining chassis hole.
Step 8 – Install the #6 solder terminal onto the screw on the inside of
the chassis. Secure with the #6 standard nut. Locate the solder end
of the #6 solder terminal away from the socket (photo 6.6e).
Proceed to 6.7
Installing the Electronics Assembly
Step 1 – Install the four #6 x 7/8” bolts into the drilled mounting holes.
Step 2 – With masking tape, tape down the heads of these screws to the
chassis to hold them in place while completing the following steps.
Step 3 – Install the four 1/2” nylon standoffs onto the four #6 x 7/8” bolts.
Step 4 – Mount the electronics assembly onto the four #6 X 7/8” bolts and
standoffs, each hole of the board corresponding to a bolt.
Step 5 – Apply four #6 KEPS nuts on the remaining exposed four #6 x
7/8” bolts and tighten them all down finger tight. The assembly can be
centered as needed.
Step 6 – Remove the masking tape and finish tightening the nuts down
tightly to the board. Proceed to 6.8
Installing and Wiring the Input Jacks
Step 1 – With the 1M resistor (brown, black, green, gold), bend both
leads and insert this resistor between the “tip” and the shorting contact
terminals of jack 1. Situate resistor on the inside of the jack (photo 6.8a).
Step 2 – Run the component lead coming from the shorting contract
terminal over to the neighboring “sleeve” or ground terminal (photo 6.8b).
Step 3 – Thread the remaining component lead coming from the “tip”
terminal over to the second jack's “shorting switch” terminal (photo 6.8b).
Step 4 – Solder the two terminals of these jacks together (photo 6.8c).
before
after
photo 6.6d
photo 6.6c
photo 6.6b
chassis edge
pin 8
photo 6.6e
6.7
photo 6.8a
photo 6.8b
6.8
NOTE
Wiring these jacks properly is a common area of confusion.
Pay close attention to both the assembly directions and wiring
layout.
photo 6.8c
NOTE
The two input holes on the outside of the chassis can be used as a temporary holding
place and spacing template while working with the input jacks. In t
his way, the proper
spacing is guaranteed when soldering the jacks together (photo 6.8c).
12 TubeDepot.com

Step 5 – From inside the chassis, install this dual jack
assembly into the appropriate chassis holes. The jack with the
1M resistor goes into input 1. The lock washers (the washers
with the teeth) go on the inside of the chassis. The flat washer
goes on the outside. Tighten down the assembly (photo 6.8d).
Step 6 – Strip and tin the end of the 3” black wire coming from
pad “G1a” and connect the wire to the sleeve / ground terminal
of the input 2 jack.
Step 7 – Strip and tin the end of the 3” yellow wire coming from
pad “a” and connect this wire to the “tip” terminal of the input 2
jack (photo 6.8d).
Step 8 – Strip and tin the end of the 3” yellow wire coming from
pad “b” and connect this wire to the point where the two jacks
are soldered together.
Step 9 – Strip and tin the end of the 3” black wire coming from pad “G2b” and connect the
wire to the sleeve / ground terminal of the input 1 jack (photo 6.8d).
Step 10 – Press all wires tight against the chassis (photo 6.8d).
Proceed to 6.9
Installing and Wiring the Volume Control
Step 1 – Feed a red wire 8” in length starting from the volume control, behind the
electronics assembly board, coming out somewhere between the preamp tube
and the speaker output jack.
Step 2 – Strip and tin the preamp tube end of this red wire and connect the wire to
pin 7 of the preamp tube.
Step 3 – Cut the alignment tab off of the volume control (photo 6.9a) and install
control into the chassis as indicated (photo 6.9b).
Step 4 – Strip and tin the volume control end of this red wire and connect the wire
to the middle lug of the volume control (photo 6.9b).
Step 5 - Strip and tin the end of the 4” yellow wire coming from pad “c” on the electronics assembly
and connect it to the volume control far right terminal (photo 6.9b).
Step 6 – Strip and tin the end of the 3” black wire coming from pad “G2a” on the electronics assembly
and connect it to the volume control right far left terminal (photo 6.9b).
Proceed to 6.10
Wiring the Power Grounds from the PCB
Step 1 – Locate the black grounding wire coming from pad G6a. Trim
this wire to 2” length. Strip the insulation 1/4” from the end of the wire
and tin the exposed strands.
Step 2 – Bend a small hook in the stripped and tinned end and
connect this wire (do not solder just yet) to the nearby terminal lug
attached to the power transformer mounting bolt nearest the fuse
holder (photo 6.10a).
Step 3 – Locate the next black grounding wire coming from pad G4a. Strip the insulation 1/4” from
the end of the wire and tin the exposed strands.
Step 4 – Repeat the same for the wire coming from pad G3a.
TubeDepot.com 13
photo 6.8d
6.9
remove this tab
photo 6.9a
photo 6.9b
When wiring the volume control, the terminals to use are the three in line terminals at the
edge of the control. The two terminals on the rear of the control are for the power switch.
CAUTION
photo 6.10a
6.10

Step 5 – Bend a small hook in these stripped and tinned ends
and connect these two wires to the nearby terminal lug
attached to the power transformer mounting bolt nearest the
fuse holder (photo 6.10a).
Step 6 – Solder these three black wires to this lug.
Proceed to 6.11
Installing the Indicator Lamp
Step 1 – Remove the nut from the bezel holder.
Step 2 – With the nut removed, remove the lamp frame.
Step 3 – Place the bezel holder in opening in the chassis.
Step 4 – Install the lamp holder on the threaded end of the bezel
holder.
Step 5 – Thread the nut onto the threaded end of the bezel holder.
Step 6 – Position the indicator lamp with the frame toward the fuse holder (photo 6.11a).
Step 7 – Tighten the nut to firmly secure the assembly to the chassis.
Step 8 – Secure the nut by painting the exposed threads with fingernail polish (photo 6.11a).
Proceed to 6.12
Installing the AC Power Cord
Step 1 – locate the cut end of the power cord and strip off the outer
black PVC insulation approximately 7 1/2” from this cut end.
Step 2 – With the three wires (white, green and black)
exposed, trim the white wire to a length of 5”, the green wire to
4” and leave the black wire at 7 1/2” length.
Step 3 – Wrap the strain relief around the black PVC jacket of
the power cord approximately 1” from where the stripped
jacket begins. Note alignment of the strain relief (photo 6.12a).
Step 4 – With a pair of slip joint pliers, firmly squeeze the
strain relief around the power cord. Grasp the strain relief and
feed the stripped end of the power cord wires into the
corresponding hole in the chassis.
Step 5 – While still grasping the strain relief with the pliers,
guide the strain relief into the chassis hole. By firmly pressing the compressed strain relief into
the hole, the strain relief should slide into place (photo 6.12b).
Proceed to 6.13
photo 6.11a
6.11
When installing the indicator lamp, be certain that no part of C6 on the electronics assembly
touches any part of the lamp holder. This may require repositioning C6 on the board.
CAUTION
The nut that secures the lamp assembly can be firmly tightened by placing the point of a
center punch on one of
the corners of the nut. Firmly tap the center punch to tighten the nut.
NOTE
6.12
photo 6.12a
The black PVC jacket of the power cord is thin and very easily cut. Be very careful not to cut
so deep as to accidentally cut the insulation of the inside
wires.
CAUTION
photo 6.12b
There is a specific tool that makes installing strain reliefs simple. If you find yourself installing
strain reliefs on a regular basis, this tool
is worth owning. See TubeDepot.com p/n TL-R-29
NOTE
14 TubeDepot.com

Installing and Wiring the Fuse Holder
Step 1 – Remove the nut from the fuse holder and insert the fuse holder into the appropriate
chassis opening. The rubber gasket goes on the outside of the chassis.
Step 2 – Reinstall the threaded nut on the fuse holder and tighten it against the chassis. Lock
the nut down by painting the exposed threads with fingernail polish.
Step 3 – Locate the “HOT” wire of the AC power cord (the black wire in the USA). Solder this
wire to the end of the fuse holder.
Step 4 – Cut a 5” piece of 18awg black wire. Strip and tin each end.
Step 5 – Solder one end of this wire to the remaining solder terminal
of the fuse holder.
Step 6 – Solder the other end of this wire to the bottom solder
terminal of the rear mounted switch on the back of the volume
potentiometer (photo 6.13a). Proceed to 6.14
Wiring the Power Switch and AC ground
Step 1 – Locate the appropriate power transformer's wire #1 primary
wires (solid brown and black wires twisted together) and solder these to the top solder
terminal of the rear mounted switch on the back of the volume potentiometer (photo 6.13a).
This is the white wire in the USA.
Step 2 – Locate the “NEUTRAL” wire of the AC power cord (the white wire in the USA).
Step 3 - Strip and tin the end of this wire.
Step 4 – Locate the solid black wire and solid brown wire from the power transformer and
strip and tin the end then twist these wires together.
Step 5 – Wrap the end of the “NEUTRAL” wire from the AC power cord with the end of the
black wire from the power transformer and solder together.
Step 6 – Fully insulate this connection with either a wire nut or with heat shrink (preferred).
Step 7 – Solder the green wire from the AC power cord to the solder terminal mounted to the
power transformer nearest the rectifier tube socket (photo 6.16a). Proceed to 6.15
6.13
By wiring the fuse holder as recommended, shock hazards are reduced when changing the
fuse because the source AC is at the far end of the fuse holder and not at the cap end.
WARNING
The original amp had a .05 ufd cap between the fuse holder and ground. Commonly referred
to as the “safety” cap, this cap can be eliminated when using a 3 wire grounded power cord
instead of a 2 wire power cord. The grounding wire of the power cord is connected to chassis
and thereby
providing the safe reference to ground instead of the old .05ufd cap.
NOTE
6.14
Photo 6.13a
It is important to choose the correct primary wires based on the mains voltage appropriate
for your location in the world. Incorrect wiring can lead to power transformer damage and/or
fire hazards.
CAUTION
The correct wire choices as per the mains voltages are as follows:
If your mainsthen the wires to use are ...
voltage is ...
wire #1 (to power switch) wire #2 (twisted to AC pwr cord))
100
black with blue stripe black
117/120
white black
220
black with yellow stripe black
230
black with green stripe black
240
black with red stripe black
CAUTION
TubeDepot.com 15

Installing and Wiring the Speaker Jack
Step 1 – Install the 1/4” Switchcraft 11A jack into the appropriate speaker
jack chassis hole. Place the lock washer (the washer with the teeth) on the
inside of the chassis.
Step 2 – Trim the black wire from the output transformer to the edge of the
chassis. Strip and tin the end of this wire and solder it to the “sleeve”
terminal of speaker jack (photo 6.15a).
Step 3 – Strip and tin the end of the 3” yellow wire coming from pad “i”
on the electronics assembly. Connect it but don't yet solder it to the “tip”
terminal of the speaker jack (photo 6.15a).
Step 4 – Check impedance of speaker and select appropriate matching
output transformer tap (see below caution).
Step 5 – Trim, strip and tin the end of this wire and solder it, along with the
previously mounted yellow wire to the “tip” end of the jack.
Step 6 – Cap off the end of the unused output transformer tap with a small
piece of electrical tape or heat shrink tubing (photo 6.15b).
Proceed to 6.16
Wiring the Rectifier Tube Socket
Step 1 – Strip and tin the end of the red wire
with the yellow line on it coming from the power
transformer. Solder this wire to the solder
terminal nearest the rectifier socket. This same
terminal has the green wire from the power cord
connected to it (photo 6.16a).
Step 2 – Strip and tin the two solid red wires
from the power transformer. Solder these to
pins 4 and 6 of the rectifier tube socket. You will notice there is also
red and white striped wires. These wires are for running the amp at
lower voltage. This will give the circuit a different sound and you can
experiment with both, but only ever connect the solid two red wires or
the red and white striped wires to the stated pins. The unused wires
must have their end covered with a small piece of the provided
heatshrink tubing (photo 6.16b).
Step 3 – Strip and tin the two yellow wires from the power transformer.
Connect these two wires to pins 8 and 2 of the rectifier tube socket.
Apply solder to pin 2 but do not yet apply solder to pin 8 (photo 6.16b).
Step 4 – Trim the red wire from pad “d”. Strip and tin this wire and
connect it to pin 8 of the rectifier tube socket. Do not solder just yet
(photo 6.16b).
Step 5 – Trim the red wire from the output transformer to the edge of
the chassis. Strip, tin and solder to pin 8 of the rectifier tube socket
(photo 6.16b). All three wires should now be soldered.
Step 6 - The remaining black wires (which are the unused multi-
voltage taps) of the power transformer should be trimmed and capped
off with either electrical tape or preferably heat shrink tubing (photo
6.16c). Do not trim the green wires yet. Proceed to 6.17
6.15
photo 6.15a
sleeve
tip
CAUTION
For 8 ohm impedances, use the green wire. For 4 ohm impedances,
use the yellow wire. Running this amp into an incorrect load can
damage the output transformer and the power tubes.
photo 6.15b
6.16
16 TubeDepot.com
photo 6.16b
photo 6.16a