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
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63
65
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5
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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
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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
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