TubeDepot 18 WATT User manual

1686 Barcrest Dr., Memphis, TN 38134
www.tubedepot.com
Learn Build Play
18 WATT TUBE GUITAR
AMP KIT
ASSEMBLY MANUAL
for the Classic “ ” style
Version 2
1 August 2 16
(with so e great “ ” style ods)
Click
here to
watch
the
asse bly
video

This manual was developed and published by:
TubeDepot.com LLC, Memphis, TN
Written by:
Robert Hull
Edited by:
Mary Klaebel
John Anderson
Design and Artwork by:
Robert Hull
Mary Klaebel
Christian Magee
Special thanks to following for their design help:
Joe Austin Brian Overstreet Mike Taylor
Matt Kirby Doug Sims Ashley Lewis
Henry Lum Ben Siler Alan Yee
Special thanks to the following for their excellent amp building and proof reading skills:
Fernando Villarreal David Hilts John Anderson
Ryan McVay Bob Buzanowki Tim and Corey Robillard
Erich Sagers Todd Farmer Timothy Dinkins
Pieter Kniest Dwight Sigouin Glenn Burgos
Copyright © 2 1
TubeDepot.com LLC
1686 Barcrest Dr.
Memphis, TN 38134
[phone]
[e-mail]
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
Acknowledge ents

Preface …...........................................................................................................
Chapter 1
Safety ….........................................................................................................
Chapter 2
Tools and Supplies .........................................................................................
Chapter 3
Parts Inventory …...........................................................................................
Chapter 4
Cabinet Preparation …...................................................................................
Chapter 5
Chassis Preparation and Assembly …...............................................….......
Chapter 6
Turret Board Assembly ….............................................................................
Chapter 7
Chassis and Turret Board Assembly …........................................................
Chapter 8
Testing …......................................................................................................
Chapter 9
Amp Final Assembly ….................................................................................
Chapter 1
Schematics, Templates, and Parts Layout
Schematic, 12AX7 input ….......................................................................
Schematic, EF86 input ….........................................................................
Wiring and Parts Layout, 12AX7 …..........................................................
Wiring and Parts Layout, EF86 …............................................................
Chapter 11
Cool Modifications …................................................................................
Appendix
A) Resistor and Capacitor Codes ................................................................
B) Soldering Hints ........................................................................................
C) Amplifier Care and Feeding ….................................................................
D) How to Swage Fit Turrets – pictorial ........................................................
E) How to Press Fit Turrets – pictorial …......................................................
F) Turret Board Drilling Templates (separate 8.5 x 14 page). See our website
for these form(s) - http://tubedepot.com/kit-british18whead.html
TubeDepot.com iii
Table of Contents
iv
1
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7
12
31
6
63
65
67
46
5
51
52
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55
54
66

Marshall amplifiers have always been the forefront in the sound of rock n' roll.
Since the early 196 's, Marshall has taken simple circuits and turned them into
extraordinary, high wattage amplifiers that to this day, continue to define tone.
With the introduction of a small 18 watt combo in the mid 6 's, Marshall took a
simple circuit, a great looking cabinet loaded with Celestion speakers, and built
an amplifier legendary for great tone. And although this incarnation lasted only
four production years, its impact continues to live on.
This British 18W kit is our nod to that original 18 watt, 1x12 combo. With turret
board, point-to-point construction, quality components, and just a touch of
American upgrading, this kit is ready to become your sound.
This construction manual has been designed with both the beginning and
experienced kit builder in mind with an assembly time of 6 - 12 hours. With
ample photos detailing every step and numerous modification suggestions, all
levels of builders will enjoy not only the process but also the finished product.
But before we get started, a safety review …
Robert Hull
Director of Technical Services
TubeDepot.com
Before continuing, PLEASE READ the following:
Preface
iv TubeDepot.com
NOTE
We are continually making improvements to this assembly manual in
an effort to provide the best instructions possible. Therefore, when
the manual's instructions differ from the video, I recommend following
these written procedures as these will be more accurate.

!!! 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
per anent physical da age 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 a p turned off and disconnected fro 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 any safety recommendations
when they appear.
Explanation of Alerts
Safety
TubeDepot.com 1
CAUTION
NOTE
Used when identifying an action that may cause damage to components
and/or equipment.
Used when identifying general points of interest.
Used when identifying an action that may cause physical injury or death.
WARNING
- DISCLAIMER -
TubeDepot.co , it's e ployees, officers, shareholders, investors and
subsidiaries accept no liability for any da age(s), injury(s) or death incurred
fro or while building or using this kit.
1
Used when identifying potential modification point(s)
MOD

As with any construction project, there are certain recommended tools and supplies. The
following are the tools and supplies NOT provided with the kit but are needed for completion.
These are expected to be 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 2 awg wire TL-VT5 21
Electric Drill (cordless recommended)
Drill bit, 1/8” - AC receptacle installation; turret board wire routing TL-DB-40125
Drill bit, 5/32” - turret board mounting TL-DB-4 156
Drill bit, 9/32” - Chassis mounting in cabinet
Drill bit, 5/16” - inset nut installation into chassis
Drill bit, 7/16” - impedance selector installation
Drill bit, 1/4” - shock mounted tube socket mounting holes
Countersink bit
Masking tape, 2” or 3”
Ruler or scale, 12” w/ 1/16” markings
Permanent marker, fine tip
Soldering iron, 25W – 4 W (35W recommended) TL-WP35
Solder, electronics safe (6 /4 w/ rosin core recommended) TS-24-6 4 - 27
Flux, electronic – liquid or paste (must be safe for electronic work) TS-83-1 - 186
De-soldering pump / solder extractor TS-384-1
Solder wick or desoldering braid TS-1817-1 F
Sponge or soldering iron tip cleaner TL-TIP-CLEANER
The following are really nice to have:
Soldering station w/ temperature control TL-WTCPT
Multimeter w/ DC range of at least 5 V TL-DVM85 BL
Variable AC supply (Variac® style)
Current Limiting AC source (dim bulb tester) – self built
Needle nose pliers – small size, for electronics work TL-NN7776
Wire cutters, diagonal – small size, for electronics work TL-17 M
Center punch – automatic center punch is great
Nutdrivers - 5/16”, 11/32”, 7/16”, 1/2”
Square, 9”
Scratch Awl
De-burring tool TL-DB-1
Fingernail polish (for holding nuts and screws in place)
Step drill bit (1/8” - 1/2”)
Orange wood stick TS-OWS
Tools and Supplies
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2

ty description part number
1 ea chassis, aluminum Marshall style 18W CH-MAR18
1 ea panel, front and back, Marshall style 18W, plastic CH-MAR18-FP
1 ea transformer, power; Marshall 18W TR-PW-12
1 ea transformer, output; Marshall 18w TR-OT-11
1 ea EZ81 JJ/Tesla rectifier tube JJ-EZ81
1 pr EL84 JJ/Tesla beam power tetrode (sold in pairs) JJ-EL84
3 ea 12AX7 JJ/Tesla JJ-ECC83
6 ea knob, Marshall style set screw P-MAR-1-4-BRASS
1 ea knob, chicken head P-FTCH-BLACK
1 ea fuse holder, low profile screwdriver cap, 3AG FH-LOWPRO
1 ea fuse, 3AG 5 mA fast blow P-BK-MDL-5 MA
1 ea fuse holder, top mount block, 3AG P-FH-BLOCK1
1 ea fuse, 3AG 1A slow-blow P-BK-MDL-1A
1 ea Indicator lamp, 6.3V incandescent w/ nut P-PL-MARSHALL1
6 ea jack, 1/4", mono closed circuit (5 1) P-CL-5 1
2 ea washer, chassis grounding (for 5 1 jack) GW-CL1442
1 ea jack, 1/4", stereo closed circuit (5 5) P-CL-5 5
2 ea switch, toggle SPST; Carling P-11 -63
2 ea washer, lock 1/2", internal tooth LW-IT-1-2
1 ea switch, 3 position rotary P-ROTARY-SWITCH
1 ea plug, AC chassis mount, snap in P-IEC-1
1 ea power cord, with IEC connector P-12PWI
2 ea screw, zinc plated 4-4 x 3/8" BP-44 -3/8
2 ea nuts, KEPS 4-4 BP-44 -KEPS
3 ea socket, tube, miniature 9pin SK-B-VT9-ST-C
3 ea socket, tube, miniature 9pin SK-B-VT9-ST-2
2 ea grommet, rubber 1/4" chassis hole / #6 screw P-GROMMET-1/4
1 ea washer, flat, #6 BP-632-SAE
2 ea grommets, rubber 1/2" chassis hole P-GROMMET-1/2
4 ea bolt, metric, M6x3 mm, stainless steel MS-M6X3 MM
4 ea washer, metric, M6, stainless steel BP-M6-WASHER
4 ea captive nuts, M6 BP-M6-CAPTIVENUT
16 ea screw, zinc plated 6-32 x 1/4", phillips pan head BP-632-1/4
7 ea screw, zinc plated 6-32 x 3/8", phillips pan head BP-632-3/8
13 ea nuts, KEPS 6x32 BP-632-KEPS
2 ea nuts, 6x32 BP-632-NUT
4 ea standoff, aluminum hex, #6 threaded, 3/4" long BP-ALSTDOFF-6-FF
Parts Inventory
3
TubeDepot.com 3

1 ea nuts, 8x32 BP-832-NUT
5 ea nuts, KEPS 8x32 BP-832-KEPS
2 ea screw, zinc plated 8-32 x 3/8", phillips pan head BP-832-3/8
3 ea solder lug, locking, #8 screw P-TERMLOCK-8
3 ea solder lug, locking, #6 screw P-TERMLOCK-6
1 ea 5 ufd / 5 ufd @ 5 V CP-JJ-5 X2-5 V
1 ea capacitor clamp, small CP-CLAMP1
1 ea 22ufd / 5 V CP-XAL-22-5 V
1 ea 22ufd / 5 V (EF86 mod part) CP-XAL-22-5 V
3 ea 47ufd / 5 V CP-XAL-47-5 V
1 ea 1 ufd / 45 V (EF86 mod part) CP-XAL-1 -45 V
4 ea 5 K audio RV24A-1 D2-15R1-A-5 K
1 ea 1K linear w/ on-off switch RV24A 2F-1 -15S1-B13
1 ea 1M linear RV24A-1 -15R1-B-1M
2 ft. wire, 2 awg, stranded, hi-temp PVC - yellow HTPVC-2 -STR-YELLOW
9 ft. wire, 2 awg, stranded, hi-temp PVC - red HTPVC-2 -STR-RED
13 ft. wire, 2 awg, stranded, hi-temp PVC - black HTPVC-2 -STR-BLACK
8 ft. wire, 2 awg, stranded, hi-temp PVC - white HTPVC-2 -STR-WHITE
5 ft. wire, 2 awg, stranded, hi-temp PVC - blue HTPVC-2 -STR-BLUE
3 ft. wire, 2 awg, stranded, hi-temp PVC – violet HTPVC-2 -STR-VIOLET
2 ft. wire, 2 awg, stranded, hi-temp PVC - orange HTPVC-2 -STR-ORANGE
7 ft. wire, 18 awg, stranded, hi-temp PVC - black HTPVC-18-STR-BLACK
3 ft. wire, 18 awg, stranded, hi-temp PVC - red HTPVC-18-STR-RED
2 ft. wire, 18 awg, stranded, hi-temp PVC – white HTPVC-18-STR-WHITE
3 ft wire, 2 awg, solid bare buss wire, tinned copper BW-2
2 ft wire, 16 awg, solid bare buss wire, tinned copper BW-16
3 ft shielded wire, interconnect IW-233
5 ft aluminum tape, 2" width, self adhesive P-TAPE-ALUM
1 ea heat shrink, 1/8" - BLACK, 6" piece TS-HS-1-8
11 in G1 red glass epoxy board (sold by the inch) BP-125BOARD-RED
62 ea turret, hollow Keystone 154 -4 BP-TURRET
3 ea 825, 1/2W metal film resistor, 1% MIL-SPEC R-CMF6 -825
3 ea 8.25K, 1/2W metal film resistor, 1% MIL-SPEC R-CMF6 -8.25K
2 ea 33.2K, 1/2W metal film resistor, 1% MIL-SPEC R-CMF6 -33.2K
1 ea 47.5K, 1/2W metal film resistor, 1% MIL-SPEC R-CMF6 -47.5K
2 ea 68.1K, 1/2W metal film resistor, 1% MIL-SPEC R-CMF6 -68.1K
5 ea 1 K, 1/2W metal film resistor, 1% MIL-SPEC R-CMF6 -1 K
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2 ea 221K, 1/2W metal film resistor, 1% MIL-SPEC R-CMF6 -221K
7 ea 47 K, 1/2W metal film resistor, 1% MIL-SPEC R-CMF6 -47 K
3 ea 1M, 1/2W metal film resistor, 1% MIL-SPEC R-CMF6 -1M
1 ea 2.2K, 1/2w metal film, 1% R-273-2.2K
1 ea 2.2M, 1/2w metal film, 1% R-273-2.2M
1 ea 22K / 1W, metal oxide power resistor (EF86 mod) R-262-22K
1 ea 8.2K, 2w metal oxide R-262-8.2K
2 ea 1. K ohm / 3W R-283-1. K
1 ea 2.2K ohm / 3W R-283-2.2K
1 ea 15 ohm / 1 W wire wound, sand cast R-CR1 -15
1 ea 47pfd / 5 V; silver mica CP-SM-47-5 V
1 ea 5 pfd / 5 V; silver mica CP-SM-5 -5 V
4 ea . 47ufd / 63 V; Mallory 15 CP-M15 - 47-63 V
4 ea . 1ufd / 63 V; Mallory 15 CP-M15 - 1-63 V
1 ea . 22ufd / 63 V; Mallory 15 CP-M15 - 22-63 V
1 ea .1ufd/63 V; Mallory 15 series CP-M15 -1-63 V
3 ea . 22ufd / 63 V; MPP radial capacitor CP-XI- 22-63 V
1 ea . 47ufd / 63 V; MPP radial capacitor CP-XI- 47-63 V
1 ea Turret setter kit DIY-PFT-KIT
----------------------------------------------------------------------------------------------------------------------------
One of the below options could be shipped with the above kit
icro head cabinet option
1 ea cabinet, small box black tolex Marshall style CAB-MAR18-HEAD
or 1X12 cabinet option (various speakers available)
1 ea cabinet, 1x12, Marshall style CAB-MAR18
4 ea flat washer, #8 BP-832-SAE
1 ea 1/4" plug, Switchcraft 28 P-28
2 ft tech flex, 1/4", yellow TS-PTNO-1-4-yellow
1 ea heat shrink, 3/8" BLACK, 6" length TS-HS-3-8
TubeDepot.com 5

The following parts are available for modifications but are NOT included with this kit.
These items must be ordered separately.
qty description part nu ber
Filter Choke Mod
1 ea choke, filter TR-CK- 2
Octal Socket Rectifier Tube Mod (does not include tube)
1 ea socket, octal SK-B-VT8-ST
Master Volu e Mod, PPMIV
1 ea 5 K dual audio pot RV24B-1 -15R1-A-5 K
1 ea knob, Marshall style set screw P-MAR-1-4-BRASS
Tone Cut Mod
1 ea 25 K linear pot RV24A-1 -15R1-B-25 K
1 ea knob, chicken head P-FTCH-BLACK
1 ea . 47ufd / 63 V; Mallory 15 CP-M15 - 47-63 V
High Perfor ance Cathode Resistor Mod
1 ea 15 , 8w wire wound (brown devil) R-B8J-15
Output Tube / Output transfor er Protection Mod
6 ea 1N4 7, 1 PIV, 1A diodes D-1N4 7
2 ea solder lug, #6 P-TERMLOCK-6
Solid State / Tube Rectifier Selection Mod
2 ea diode 1N4 7, 1 PIV, 1A diodes D-1N4 7
1 ea Switch, mini-toggle SPDT P-1 8-MINI-1
1X12 cabinet option (does not include speaker)
1 ea cabinet, 1x12, Marshall style CAB-MAR18
4 ea flat washer, #8 BP-832-SAE
1 ea 1/4" plug, Switchcraft 28 P-28
4 ft. wire, 2 awg, stranded, hi-temp PVC - black HTPVC-2 -STR-BLACK
4 ft. wire, 2 awg, stranded, hi-temp PVC - white HTPVC-2 -STR-WHITE
2 ft tech flex, 1/4", yellow TS-PTNO-1-4-yellow
1 ea heat shrink, 3/8" BLACK, 6" length TS-HS-3-8
Marshall Style 50W s all box
1 ea cabinet, small box black vinyl Marshall style CAB-MAR-SMBOX
Marshall Style 20W icro box
1 ea cabinet, micro box black vinyl, Marshall style CAB-MAR18-HEAD
Tre olo hi / lo Speed Selection Mod
1 ea Switch, mini-toggle SPDT on-off-on P-1 8-MINI-1
1 ea 47 K, 1/2w metal film, 1%, 5 V rated R-CMF6 -47 K
1 ea 1M, 1/2w metal film, 1%, 5 V rated R-CMF6 -1M
6 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 with the cabinet.
Cabinet Inventory
Co bo Cabinet
1. Handle w/ ounting hardware – There should be a single flat black handle with two
gold end covers mounted to the top of the cabinet.
2. Feet, rubber – There should be four rubber 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 four panel screws. All panel screws should have a finishing washer.
4. Baffle screws – There should be eight black oxide coated screws with matching
black finishing washers holding the baffle in the cabinet.
5. Speaker bolts – There should be four black oxide coated bolts for securing the
speaker to the baffle board.
Head Cabinet
1. Handle w/ ounting hardware – There should be a single flat black handle with two
gold end covers mounted to the top of the cabinet.
2. Feet, rubber – There should be four rubber feet attached with screws to the underside
of the cabinet.
3. Back panel w/ screws – The back panel should be secured with four panel screws.
With either cabinet, I encourage inspecting all assembly screws to insure they are tightly
holding the cabinet together. In the past I've found that sometimes some screws aren't fully
tightened down during assembly.
Drilling the Four Chassis Mounting Bolts (Head and Co bo)
4.2.1 Co bo Cabinet
Step 1 – Remove the back panel and lay the
panel on the work table with the vinyl covering
facing down.
Step 2 – With the empty aluminum chassis,
center the chassis on the back panel with the
control panel side of the chassis flush against the
back panel cutout (photo 4.2a).
Step 3 – Make a mark through each of the four
mounting holes of the chassis onto the cabinet
Cabinet Preparation
4
TubeDepot.com 7
4.2
4.1
CAUTION The following steps call for drilling the mounting holes in the cabinet for the chassis. Make
sure to review, reread and remeasure at each step to reduce potential drilling errors.
Because (as the wise old amp builder's saying goes) what is drilled, cannot be undrilled.
photo 4.2a

back panel (photo 4.2a).
Step 4 – Place the chassis to the side and with a 1/8” drill bit, drill a small pilot hole in the
center of each of these marks.
Step 5 – Once the pilot holes have been drilled, drill the final 9/32” hole down the center of
each of these pilot holes.
Step 6 – With a hobby knife, clean the edges of the holes by cutting off any excess vinyl
covering left from the drilling operation.
4.2.2 Head Cabinet
Step 1 – Remove the back panel and place to
the side.
Step 2 – Place the cabinet upside down with the
handle against the work bench and the front of
the cabinet facing you.
Step 3 – Lay a strip of masking tape along each
cabinet edge on the outside of the feet.
Step 4 – On both strips of masking tape, make
two marks 1 1/4” from the outside edge of the
cabinet. Place one of these marks near the
cabinet front and one mark near the cabinet back
on each strip (photo 4.2b). It is important to use a
hand square in order to get the correct 1 1/4” measurements.
Step 5 – On both strips of masking tape, draw a line connecting these
front and back marks (photo 4.2b).
Step 6 – On both strips of masking tape, make a mark 1 1/2” from the
back edge of the cabinet intersecting the previously drawn line (photo
4.2b).
Step 7 – With the chassis in hand, align the mounting holes of the
chassis over the connecting line with one of the chassis holes over the
intersecting mark (photo 4.2c).
Step 8 – Make another mark through the remaining mounting hole of the
chassis on the connecting line (photo 4.2d) and lay the chassis to the
side.
Step 9 – Repeat steps 7 and 8 for the opposite edge.
Step 10 – Drill a small 1/8” pilot hole in the center of each of the four marks.
Step 11 – Drill the final 9/32” hole in each of these four pilot holes and remove the masking
tape.
Step 12 – Test fit the chassis to the cabinet and make any adjustments as needed.
8 TubeDepot.com
photo 4.2b photo 4.2c
photo 4.2d
If you have a square drive bit, the feet are easily removed. And with the feet removed, it is
much easier and faster to insure that the mounting holes are correctly spaced prior to drilling.
NOTE

Installing the Shielding Tape (Head and Co bo)
4.3.1 Co bo Cabinet
Step 1 – Place the cabinet back panel with
the vinyl side down toward the desk.
Step 2 – Cut three lengths of shielding tape,
each 2 ” long.
Step 3 – Remove the backing from the first
of these 2 ” shielding tape strips.
Step 4 – Apply the aluminum tape to the
back of the panel centered between the
chassis mounting holes.
Step 5 – Remove the backing from the
second shielding tape strip and apply the
tape to the back of the panel along the lower
edge of the previous tape, overlapping about
1/8” the entire length (photo 4.3b).
Step 6 – Remove the backing from the final shielding tape strip and apply the tape to the
back panel along the upper edge of the first tape, overlapping about 1/8” along the entire
length (photo 4.3b).
Step 7 – Clear the mounting holes by cutting the shielding tape from around the holes with a
hobby knife.
4.3.2 Head Cabinet
Step 1 – Place the cabinet with the back open toward you.
Step 2 – Cut three lengths of shielding tape, each 18” long.
Step 3 – Remove the backing from the first of the 18” shielding tape strips.
Step 4 – Apply the first aluminum
tape strip to the inside of the
cabinet, centered down the middle
between the chassis mounting
holes (photo 4.3c).
Step 5 – Remove the backing from
the second shielding tape strip and
apply the tape to the cabinet along
the lower edge of the previous
tape, overlapping about 1/8” the
entire length.
Step 6 – Remove the backing from the final shielding tape strip and apply the tape to the
4.3
TubeDepot.com 9
CAUTION 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 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.
photo 4.3a
photo 4.3b
photo 4.3d
photo 4.3c

cabinet along the upper edge of the first tape, overlapping about 1/8” along the entire length
(photo 4.3d).
Step 7 – Clear the mounting holes by cutting the shielding tape from around the holes with a
hobby knife.
Wiring the Speaker Cable to the Speaker (Co bo Cabinet)
Step 1 – Measure a 14” length of white 18AWG wire, and a 14” length of black 18AWG wire.
Step 2 – Twist these black and white wires tightly together the full length.
Step 3 – At one end of this twisted pair, strip the insulation back ½ ” from both wires and tin
these two wires
Step 4 – Unscrew the barrel of the ¼ ” phone plug and solder the
two tinned wires to the plug; white to center and black to shield
(photo 4.3a).
Step 5 – Slide the length of yellow Techflex over this twisted pair
right up to the center conductor of the plug (photo 4.3b).
Step 6 – Slide the 3” length of 3/8” heat shrink up over the
Techflex up to the center conductor of the plug (photo 4.3b).
Step 7 – Shrink the heat shrink in place with a heat gun (photo 4.3b)
Step 8 – Install the remaining 3” heat shrink length over the tech flex at the
opposite end of the twisted pair near the cut end.
Step 9 – Shrink the heat shrink in place with a heat gun.
10 TubeDepot.com
4.4
photo 4.3a
NOTE
The ¼” phone plug was invented for use in telephone switchboards in 1878. And although it
is no longer used for telephone switching, this great plug has become the standard
connection type between musical instruments and outboard equipment.
CAUTION Be careful when applying heat to the heatshrink, especially at the point where the techflex
and heatshrink meet. The techflex will quickly melt if excess heat is applied.
photo 4.3b
To get an even, tight twist, use a handheld drill to twist the two wires together. Place the
loose wire ends into the drill chuck and slowly turn the drill until the wires are tightly
twisted..
NOTE
photo 4.3c
For hints on improved soldering skills, review Appendix B at the end of this manual.
Additionally, see “How to Solder”, http://www.youtube.com/watch?v=cIDydYIVTqU
NOTE

Step 10 – At the opposite end of the twisted wire pair, strip back the insulation ¼” and tin
these two wires.
Step 11 – Solder these wires to the terminals of the speaker; the white wire to the “+” terminal
and the black wire to the “-” terminal (photo 4.3c).
Mounting the Speaker in the Cabinet (Co bo Cabinet)
Step 1 – Remove the four speaker mounting screws
from the speaker baffle board.
Step 2 – With speaker in hand, carefully align the
speaker mounting holes to the baffle board mounting
holes (I recommend installing the speaker with
connecting terminals on top).
Step 3 – Install a single #8 flat washer on each of the
four mounting screws prior to installation.
Step 4 – Install the four mounting screws through the
speaker mounting holes into the baffle board. Firmly
tighten down.
4.4
TubeDepot.com 11
photo 4.4a
The combo kit can be ordered without a speaker leaving the choice of speaker up to you.
It is recommended that the power rating of the speaker is at least 35W.
NOTE
NOTE The choice of stock speaker is determined by what we have on hand. This usually
alternates between either the Weber or Celestion speakers, both of which are excellent.

Installing the Captive Nuts into the Chassis
Step 1 – Identify the four mounting holes on the outwardly bent
flange edges of the chassis, two on each edge.
Step 2 – With a 5/16” drill bit, enlarge all four of these holes and
remove any burrs.
Step 3 – Place the chassis, flange down, on a flat solid surface
(concrete floor is good).
Step 4 – Place an inset nut on the flange directly over one of the
newly drilled 5/16” holes (photo 5.1a).
Step 5 – With a few blows from a hammer to the top of the insert nut, seat
the nut firmly into the hole and flush against the chassis flange.
Step 6 – Inspect the nut to insure it is well seated (photo 5.1b). Repeat step
5 as needed.
Step 7 – Repeat above for the remaining three nuts.
Installing the 1/2” Gro ets
Step 1 – Press the two 1/2” grommets into the two appropriate chassis holes on either side of
the output transformer mounting position making sure the grommets are fully seated.
Installing the Power Transfor er
Step 1 – Twist all the wires of the power transformer loosely together and insert
them through the square chassis mounting hole.
Step 2 – Position the transformer in the chassis with the red and yellow wires
toward the back of the chassis and the black and green wires toward the front.
Step 3 – Seat the transformer against the chassis and install three
appropriately bent #8 solder terminals (photo 5.3a) to three of the four transformer mounting
bolts (see wiring layout on pg 53 for which three bolts). Arrange these three terminals so they
are pointed in the directions as indicated on the wiring layout pg 53.
Step 4 – Install a #8 standard nut on each of these bolts and firmly tighten. Make sure that
the #8 solder terminals remain in position while tightening.
Step 5 – Install a #8 KEPS nut on the remaining transformer bolt and firmly tighten.
12 TubeDepot.com
5.2
photo 5.1a
5.3
photo 5.3a
NOTE
There are several great modifications that are possible on this amp. I recommend
reviewing these mods prior to beginning the following assembly steps to see if there is
something that interests you. It is easier to install most modifications during initial
assembly than later.
5.1
MOD
If you want to expand the potential range of rectifier tube selections beyond the stock 9 pin
EZ81, now is the best time to enlarge the size of the present rectifier chassis hole to accept
an octal socket. See “Cool Modifications”, Chapter 11 for more information.
photo 5.1b
5
WARNING During all drilling and cutting operations, it is important to wear proper eye protection and
follow appropriate safety precautions.
Chassis Preparation
and Asse bly

Installing the Output Transfor er
Step 1 – Twist the blue, red, and brown wires tightly together.
Step 2 – Twist the black, yellow, green, and orange wires together.
Step 3 – Place the output transformer on the chassis and feed the red,
blue, and brown wire bundle through the chassis mounted grommet
nearest the power transformer.
Step 4 – Feed the black, yellow, green, and orange wires through the
chassis mounted grommet on the opposite side of the output
transformer.
Step 5 – Mount the output transformer to the chassis with the two 8-32 x
3/8” screws and two #8 KEPS nuts.
Installing the Capacitor and Capacitor Cla p
Step 1 – Prior to chassis installation, loosely tighten the clamp to the
can capacitor.
Step 2 – Install the cap clamp assembly to the chassis with the
clamp adjustment screw placed nearest the power transformer (photo 5.5a).
Step 3 – Secure the clamp to the chassis with two 6-32 x 3/8” screw and two #6 KEPS nuts.
Step 4 – Turn the chassis over and rotate the cap in the clamp until the common terminal is
inline with the solder terminal (photo 5.5b).
Step 5 – Turn the chassis back over and firmly tighten the can capacitor in the clamp.
Installing the Shock Mounted V1 Prea p Tube
Step 1 – With a 1/4” drill bit, enlarge the two V1 tube socket mounting
holes in the chassis. Deburr any rough edges.
Step 2 – Insert the two 1/4” grommets in these holes, making sure they
are properly seated in the chassis.
Step 3 – Prior to mounting the preamp tube sockets, slightly bend the
terminals 1 - 3 and 6 – 9 outward of the tube socket (photo 5.6a).
Step 4 – Carefully bend terminals 4 and 5 together. The holes of these terminals should meet
close to each other (photo 5.6a).
Step 5 – To provide a flat surface for the mounting screws, use a pair of needle nose pliers to
carefully bend the edges of the shield near the screw mounting holes inward toward the
socket (photo 5.6b, c, and d).
Step 6 - Insert the tube socket from the outside of the chassis and rotate the socket so that
pin 6 of the tube is closest to the chassis edge / corner.
Step 7 – Mount the tube socket with two 6-32 x 3/8” screws (photo 5.6e).
5.4
5.5
photo 5.5b
TubeDepot.com 13
5.6
photo 5.5a
photo 5.6a
The terminals of these sockets are very fragile and will easily break if bent too far. It is
recommended to use needle nose pliers for better control when bending these terminals.
CAUTION
For the EF86 mod, do not bend terminals 4 and 5 together in Step 4. Refer to Chapter 11,
“Cool Modifications” for more information.
MOD

Step 8 – On the inside of the chassis,
install a #6 flat washer on the screw
near the chassis edge.
Step 9 – Install a #6 KEPS nut on this
screw (not overly tight, so the socket
can slightly rock back and forth in the
grommets) nearest the chassis edge
and seal in place with a drop of
fingernail polish (photo 5.6e and 5.6f).
Step 10 – Install a #6 solder terminal on the
opposite screw.
Step 11 – Secure the solder terminal with a
#6 standard nut (not overly tight, so the
socket can slightly rock back and forth in the
grommets) and seal in place with fingernail
polish (photo 5.6f).
Installing the V2 – V6 Tube Sockets
Step 1 – Prior to mounting the preamp tube sockets (V2 and V3), slightly bend the solder
terminals 1 - 3 and 6 – 9 outward as well as bend terminals 4 and 5 together (photo 5.6a).
This is for the preamp tubes only. Do not bend the 4 & 5 pins together for the power tubes.
Step 2 – Bend the mounting edges of the tube socket inward to allow installation of the
screws (photo 5.6b, c, and d).
Step 3 – Insert the tube socket from the outside of the chassis and rotate the socket so that
pin 6 of the tube is closest to the chassis edge / corner.
Step 4 – Insert a #6 x 1/4” screw into each mounting hole of each socket from the outside of
the chassis and secure the socket on the inside of the chassis with a #6 KEPS nut.
Step 5 – Repeat the above steps for V2 through V6 tube sockets.
Installing the Faceplate, Input Jacks, Controls & Switches
Step 1 – While holding the faceplate against the front of the amp, install the first vibrato
channel LO sensitivity input jack (the one deeper inside the chassis). The jack should be
installed with one fiber washer on the inside of the chassis and the solder terminals should be
facing toward the normal channel section.
Step 2 – Install one fiber washer and a grounding washer on the second vibrato channel high
sensitivity jack and install this jack with these washers into the chassis above the previous
5.8
14 TubeDepot.com
Refer to the “Cool Modifications”, Chapter 11 section for modifying the amp from the 9 pin
EZ81 rectifier to the more versatile OCTAL rectifier options.
MOD
5.7
The terminals of these sockets are fragile and will easily break if bent too far. It is
recommended to use needle nose pliers for better control when bending these terminals.
CAUTION
photo 5.6b photo 5.6c photo 5.6d
photo 5.6e
photo 5.6f >

jack. The solder terminals should be facing the normal channel section.
Step 3 – Install the normal channel LO sensitivity jack (the one deeper inside the chassis) into
the chassis with one fiber washer and with the terminals facing the chassis side.
Step 4 – Install one fiber washer and a grounding washer on the normal
channel HI sensitivity jack and install this jack with these washers into the
chassis above the previous jack. The solder terminals should be facing the
chassis side.
Step 5 – Bend the alignment tab of all of the 1M audio taper pots against the
potentiometer body prior to mounting. Or they can be broken off too.
Step 6 – Install the four 5 K audio taper pots in the “volume” and “tone”
control positions of the normal and vibrato channels. Position these controls
with the solder terminals facing up for easy soldering.
Step 7 – Break the alignment tabs off of the remaining 1K w/ switch pot and the 1M pot.
Step 8 – Install the 1K pot with switch in the “intensity” control spot and the 1M pot in the
“speed” control spot. Install these controls with the flat washers on the faceplate side and with
the solder terminals facing up for easy soldering.
Step 9 – Install the two Carling SPST toggle switches in the AC power and STANDBY
positions. Install with the solder terminals facing up for easy soldering.
Installing the 6.3V Indicator La p
Step 1 – Twist the wires of the indicator lamp tightly together, being careful
not to pull the body of the lamp out of the back of the red lens.
Step 2 – Feed the twisted wires of the indicator through the front panel
mounting hole.
Step 3 – Once the indicator is in place, slide the press nut over the wires
and firmly slide the nut into place over the body of the indicator lamp and as
flush as possible against the inside chassis front.
Step 4 – Rotate indicator until it is properly aligned and use a little fingernail
polish on this inside push nut to hold it in place.
Wiring the V1 – V5 Tube Fila ents
Wiring the power transformer filament center tap
Step 1 – Locate the green wire with the yellow stripe on it coming from the power transformer.
Step 2 – Cut this wire to a 3” length and strip and tin the end.
5.9
5.10
TubeDepot.com 15
If you are installing an EF86 instead of a 12AX7 tube as the first channel (normal channel)
preamp tube, then V1 filament will be wired differently than described below. See “Cool
Modifications”, Chapter 11 for more information
Get a footswitchable HI / LO speed control by installing a mini SPDT toggle switch between
the words “vibrato” and “off”. See “Cool Modifications”, Chapter 11 for more information.
MOD
MOD
photo 5.9a
This is probably the most challenging task in this entire kit build. Making the filament
installation look great takes great attention to detail and a very lite use of heat when
soldering. I recommend going very slow and be prepared to redo several times. Good
luck.
NOTE
bend this tab out of
the way

Step 3 – Bend a small hook in the end of this wire and solder the wire to the nearby #8 solder
terminal at the corner of the power transformer nearest the power (on/off) switch.
V1 wiring
Step 1 – Cut a 26” length of 2 AWG red wire and an equal 26” length of 2 AWG black wire.
Step 2 – Twist these two wires tightly together the full length.
Step 3 – Untwist these wires about 2” from one end of the twisted pair and strip and tin the
black wire at this end.
Step 4 – Install the tinned end of the black wire into terminals 4 and 5
together of V1 and solder.
Step 5 – Route the black wire tightly against the chassis and to the
rear chassis edge.
Step 6 – Form a 9 degree angle in the black wire at the chassis
edge and lay the remaining wire pair in this corner chassis edge
behind the remaining tube sockets.
Step 7 – With the loose red wire end, measure an adequate running
distance from the 9 degree angle in the black wire (about 1/2” is
good and re-twist this red wire with the black wire to maintain
uniformity) and make a sharp 9 degree bend in the red wire.
Step 8 – Run this wire up to terminal 9 of the V1 tube socket and
make another 9 degree bend in the red wire so that the red wire
points directly toward terminal 9.
Step 9 – Cut the red wire approximately 1/4” to 3/8” from this second bend.
Step 10 – Strip and tin this end and solder it to pin 9 (photo 5.1 a). Try to apply as little heat
as possible (solder quickly) so that the insulation doesn't contract too much.
Step 11 – Trace the twisted pair over to the opposite side of the V2 tube socket (between V2
and V3). Bend a 9 degree bend in the twisted pair from the chassis edge in line with pin 9 of
V2 socket.
Step 12 – Cut the wire pair approximately 1 1/2” inch from the chassis edge where the 9
degree bend is and lay the remaining wire pair to the side.
V2 wiring
Step 13 – Untwist the wires approximately 2” from the cut end and run the red wire tightly
along the chassis edge and up to terminal 9 of V2. Reform the 9 degree bend as necessary
to maintain uniformity.
Step 14 – Make another 9 degree bend in this red wire so that the red wire points directly
into terminal 9 and cut 1/4” to 3/8” after this second bend.
Step 15 – Strip and tin the red wire and insert into pin 9 of V2. Do not solder just yet.
Step 16 – Position the black wire against the chassis and re-twist the black wire around the
red wire as needed to maintain uniformity.
16 TubeDepot.com
To get an even twist and to speed up the filament wiring process, use a handheld drill to
twist the two wires together. Place the loose wire ends into the drill chuck and rotate the
drill slowly until the wires are tightly twisted..
NOTE
photo 5.10a
For hints on improved soldering skills, review Appendix B at the end of this manual.
Additionally, see “How to Solder”, http://www.youtube.com/watch?v=cIDydYIVTqU
NOTE