Learn Build Play

Learn Build Play
Learn
Build
Play
Assembly Manual
Tweed Champ 5E1 - 5F1
Instructions for Assembling with the:
- Printed Circuit Board (PCB)
with additional modification suggestions and recommended amp settings
version 1.0
March 16, 2009
Table of Contents
This manual was developed and published by:
TubeDepot.com
Memphis, TN
Written by:
Robert Hull
Edited by:
Mary Klaebel
Design and artwork by:
Robert Hull
Mary Klaebel
Christian Magee
Acknowledgements:
Special thanks to:
Joe Austin
Matt Kirby
Henry Lum
Brian Overstreet
Ben Siler
Doug Simms.
Copyright © 2009
TubeDepot.com
1686 Barcrest Dr.
Memphis, TN 38134
(901)388-2286
[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.
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Table of Contents
page
Preface and Champ 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 …......................................................................................................... 19
Chapter 8
Testing …..................................................................................................................... 20
Chapter 9
Schematics and Parts Layout ….................................................................................. 23
Chapter 10
Cool Modifications …................................................................................................... 27
Appendix
A. How to Read Resistor and Capacitor Codes …....................................................... 28
B. Soldering Hints ….................................................................................................... 31
C. Amplifier Care, Feeding, and Application Hints …................................................... 33
D. Drilling Templates …................................................................................................ 35
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Preface
Short History of the Tweed Fender
TM
Champ
With just 4 watts, the first incarnation of the Fender TM 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 600TM ” 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 TM 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 W. Hull Jr.
Director of Technical Services
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1 Safety
!!! 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.
- DISCLAIMER TubeDepot.com, it's 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.
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
WARNING
- Used when identifying an action that may cause physical injury or death.
CAUTION
- Used when identifying an action that may cause damage to components
and/or equipment.
NOTE
- Used when identifying general points of interest.
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2 Tools and Supplies
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.
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The following is our recommended list:
part number
Phillips screwdriver, #1 and #2
Slip joint pliers
Needle nose pliers
Wire cutters, diagonal
Wire strippers, for 18 and 20 awg wire
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
TL-VTSCRSET8
Soldering iron, 25W – 40W (35W recommended)
Solder, electronics safe (60/40 w/ rosin core recommended)
Flux, electronic – liquid or paste (must be safe for electronic work)
De-soldering pump extractor
Solder wick
Sponge
TL-WP35
TS-24-6040-0027
TS-83-1000-0186
TS-384-1000
TS-1817-10F
TL-VT33
TL-VT33
TL-VT5021
The following are really nice to have:
Soldering station w/ temperature control
Multimeter w/ DC range of at least 500V
Variable AC supply (Variac style)
Current Limiting AC source (build directions in this manual)
Needle nose pliers – small size, for electronics work
Wire cutters, diagonal – small size, for electronics work
Center punch
Nutdrivers - 5/16”, 11/32”, 7/16”, 1/2”
Square, 9”
Scratch Awl
heat shrink, 1/4” x 6”
De-burring tool
Fingernail polish (for holding nuts and screws in place)
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TL-WTCPT
TL-DVM850BL
TL-NN7776
TL-170M
TS-HS-ASST-7
3 Parts Inventory
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
1 speaker, 8" Jensen MOD, 4ohms
1 chassis, steel chrome plated champ 5E1/5F1
1 cabinet, tweed champ 5E1/5F1
1 PCB board, 5E1/5F1
transformers
1 transformer, power tweed champ
1 transformer, output tweed champ
tubes
1 5Y3 rectifier tube
1 6V6GT beam power tetrode
1 12AX7 dual triode
panel hardware
1 knob, vintage pointer
1 fuse holder, conical cap, vintage Fender style
1 fuse, 3AG 2A slow-blow
1 lamp holder
1 jewel, red
1 lamp, #47, 6.3 V
2 jack, 12A, shorting, switchcraft ¼"
1 jack, 11A, open, switchcraft ¼"
3 washer, lock 3/8"
1 plug, switchcraft ¼"
power cord hardware
1 power cord, grounded three prong, 12'
1 strain relief, heyco
1 nylon cable clamp
1 screw, zinc plated #8 x 5/8", phillips flat head
tube sockets
1 socket, tube, miniature 9pin
2 socket, tube, octal
hardware
2 grommets, rubber 3/8" hole
2 bolt, 1 1/2" 10x32 truss screw
2 nuts, KEPS 10x32
6 screw, zinc plated 6-32 x 1/4", phillips pan head
9 nuts, KEPS 6x32
1 nuts, 6x32
4 nuts, KEPS 8x32
2 nuts, 8x32
4 screw, zinc plated 6-32 x 7/8" phillips pan head
4 standoff, nylon; L = .5"; id = .140"; od = .250"
2 screw, zinc plated 8-32 x 1/4", phillips pan head
2 solder lug, locking, #8 screw
1 solder lug, locking, #6 screw
electronic, resistors
2 100, 1/2w carbon film
2 68K, 1/2w carbon film
1 1M, 1/2w carbon film
2 100K, 1/2w carbon film
2 1.5K, 1/2w carbon film
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1686 Barcrest Dr.
Memphis, TN 38134
(877) 289-7994
[email protected]
Application
speaker
chassis
cabinet
printed circuit board
power transformer
output transformer
rectifier tube
power tube
preamp tube
knob
fuse holder
fuse
lamp holder
lamp jewel
lamp
input jack
speaker jack
jack lock washer
speaker plug
power cord
power cord strain relief
power cord clamp
cord clamp mounting
preamp tube
rectifier / power tube
grommets
chassis mounting
chassis mounting
tube socket mounting
tube socket / PCB mounting
tube socket w/ solder tab mounting
power / output transformer mounting
power transformer w/ solder tab mounting
PCB mounting
PCB mounting
output transformer mounting
grounding at power transformer
grounding at preamp tube socket
filament pseudo center tap
input resistors
input biasing resistor
preamp tube plate resistors
preamp tube cathode resistors
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2 68K, 1/2w carbon film
1 22K, 1/2w carbon film
1 220K, 1/2w carbon film
1 470, 3w metal oxide
1 10K, 2w metal oxide
1 22K, 1w metal oxide
electronic, capacitors
2 .022ufd / 400v
2 22ufd / 50V
1 22ufd / 450V
2 10ufd / 450V
electronic, potentiometers
1 1M pot w/ on-off switch (Alpha )
1 100K trim pot, horizontal mount
wire
3 wire, 20 awg, stranded, hi-temp PVC – yellow
2 wire, 20 awg, stranded, hi-temp PVC – red
2 wire, 20 awg, stranded, hi-temp PVC – black
2 wire, 18 awg, stranded, hi-temp PVC – green
2 wire, 18 awg, stranded, hi-temp PVC – black
2 wire, 18 awg, stranded, hi-temp PVC – white
shielding
3 alumimum tape, 3" width, self adhesive
heat shrink
5 heat shrink, 1/4" - black, 1" piece
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input resistors
feedback resistor
biasing resistor
cathode resistor
B+ resistor
B+ resistor
coupling caps
cathode bypass caps
power supply filter cap
power supply filter caps
volume / power switch
feedback adjustment
board, general wiring
board, signal / B+ wiring
board, ground wiring
filament wire
speaker wire, speaker wire, +
electrical and heat shielding
wire dressing / capping
4 Cabinet Preparation
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 oxide coated bolts for securing
the speaker to the baffle board. Additionally, there should be four KEPS nuts, one on
each of these bolts to be used when mounting the speaker.
the Two Chassis Mounting Bolt Holes
4.1 Drilling
The cabinet is not drilled for the chassis mounting bolts. Therefore two holes, one on
each side of the top of the cabinet opening must be drilled for installation of these 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 – Remove template page
from manual (appendix D1) and
fold on indicated line.
Step 5 – Place template on top
of cabinet, properly centered
photo 4.1B
photo 4.1A
over the opening (photo 4.1B).
CAUTION
Be certain of template placement before drilling. The rounded edges of the cabinet can skew
measurements and cause improper placement. Always measure several times before drilling.
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 and 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, it is time to drill. Drill two
3/16” holes, one at each of these two marks all the way through
the top of the tweed cabinet.
photo 4.1C
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Step 9 – Remove the masking tape.
Step 10 – Clean up any loose splinters and / or tweed from
the holes and test fit the chassis mounting bolts.
Step 11 – With the chassis mounting bolts in the cabinet, test fit the chassis onto the bolts
Step 12 – Remove chassis and reinstall handle, leaving chassis mounting bolts installed.
Proceed to 4.2
4.2 Installing the Speaker
Step 1 – Remove speaker from its shipping box, inspecting it for any damages
Step 2 – Remove the four nuts from the speaker mounting bolts inside the cabinet.
Step 3 – With speaker in hand, carefully align the speaker mounting holes to these baffle
bolts. I recommend installing the speaker with connecting terminals on top.
Step 4 – 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).
CAUTION
Alignment of all holes during installation is important. Otherwise, one or more of the bolts may
puncture the speaker cone by accident.
photo 4.2A
photo 4.2C
photo 4.2B
Step 5 – Once the speaker is installed on the bolts,
install and tighten the KEPS nuts.
Proceed to steps 4.3
photo 4.3a
4.3 Wiring the Speaker
photo 4.3b
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.
NOTE
The ¼” phone plug was invented for use in telephone switchboards in 1878. 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 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 the opposite end of the twisted wire pair, strip back the
insulation ¼” and tin these two wires.
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photo 4.3c
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
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
photo 4.3e
lengths of 10”
Step 3 – Remove the backing from the first of the three shielding tape strips.
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.
Step 4 – Apply the aluminum tape to the back of the
panel, 1/8th of an inch from the top of the panel and
centered between the two side panel edges (photo
4.4A).
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
photo 4.4B
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
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5 Circuit Assembly
Here is where good soldering skills and attention to detail will pay off. By following these
directions, you should have no trouble in completing the circuit assembly quickly and without
errors.
I encourage you to first read all 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.
Circuit Board (PCB) Assembly
5.1 Printed
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-topoint 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 in a third. The
resistors will be installed first. They have no polarity and can therefore be installed in either
direction safely.
NOTE
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”.
Step 2 – Install a 1.5K / ½ watt resistor (brown, green, red, gold) in R6
position.
Step 3 – Install two 6.8K / 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
photo 5.1A
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.
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.
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.
Step 12 – 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 13 – 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 14 – Install the 100K trimmer pot.
Step 15 – 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.
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Step 17 – 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).
CAUTION
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.
Step 18 – Install the 22ufd / 450V filter capacitor in position C6.
This component has a polarity, therefore it must be installed
according to case and board markings (photo 5.1b).
photo 5.1b
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 to this pad. Measure
and cut this wire to a length of 3” from pad G1a
(photo 5.2a).
Step 2 – Repeat above for pad G3a & G3b.
Step 3 – Repeat above for pad G4a except extend
wire to 4”.
Step 4 – Repeat above for pad G6a.
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 to this pad. 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
photo 5.2a
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 to this pad. 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
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6 Chassis Preparation
6.1 Drilling Mounting Holes for the Printed Circuit Board (PCB)
Step 1 – Locate the template labeled
“drilling template chassis/5F1” in Appendix
D1A.
Step 2 – Situate the chassis with the large
chrome side facing up and the printed
control panel facing toward you.
Step 3 – Place the template onto the
chassis. Make sure the template markings
photo 6.1a
photo 6.1b
line up with the actual chassis cutouts.
Step 4 – On the template, locate the four concentric circular drill indicators (photo 6.1a).
Step 5 – 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).
NOTE
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.
Step 6 – Utilizing the printed measurements from the template, verify that these marks are
correctly situated on the chassis.
Step 7 – Once verified, drill four, 5/32” holes, one hole at each of these marked spots.
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.
Step 8 – Remove any burrs around holes. A de-burring tool is very helpful here.
Proceed to step 6.2
6.2
Installing the Power Transformer
Step 1 – Loosely twist all wires together.
Step 2 – Situate the transformer so that the primary wires (black
wires) will be nearest the fuse holder and the secondary wires (reds,
yellows, greens) will be nearest the tube socket.
Step 3 – Guide the wire bundle through chassis opening.
Step 4 – Install and tighten two #8 KEPS nuts on the transformer
bolts nearest the edge side of the chassis (photo 6.2a).
Step 5 – Bend the #8 solder tabs at a slight angle (photo 6.2b).
Step 6 – Install two solder tabs on the remaining two transformer bolts,
oriented at angles toward the chassis edges (photo 6.2a).
Step 7 – Install and tighten the two #8 standard nuts on these last two
bolts with the solder tabs (photo 6.2a). As the nuts are tightened, be
careful to keep the solder tabs from changing position.
Proceed to 6.4
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--- KEPS nuts ---
photo 6.2a
Photo 6.2b
6.3 Installing the Rubber Grommets
Step 1 – locate the two rubber grommets from the parts
provided . Then locate the two corresponding holes
photo 6.3a
on the chassis.
Step 2 – Insert the two rubber grommets in the
chassis holes (photos 6.3a and 6.3b).
Proceed to 6.3
photo 6.3b
6.4 Installing the Output Transformer
Step 1 – Twist the red and blue 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 and blue wires go into the grommet nearest the power
transformer.
Step 4 – With both wire bundles pulled through the grommets and the
transformer flush on the chassis, locate the two #8 KEPS nuts and
the two #8 x 1/4” screws.
Step 5 – Secure the output transformer to the chassis. The two
KEPS nuts should be mounted on the inside of the chassis.
Proceed to 6.5
photo 6.4a
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).
CAUTION
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.
Step 2 – Insert the socket from the outside of the chassis.
Rotate both sockets so that Pin 2 is closest to the chassis
opening 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
6.6 Installing the 9 pin Tube Socket
Pin 2 -----
Photo 6.5A
Photo 6.5B
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.
CAUTION
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.
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).
Photo 6.6A
5 4
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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, C, and D).
after
before
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
photo 6.6D
photo 6.6B
photo 6.6C
chassis with the outside hole (photo 6.6E).
Step 6 – Now bend the #6 solder tabs at a
slight angle.
Step 6 – Insert a #6 x 1/4” screw into the remaining chassis hole.
Step 7 – 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).
pin 8
Proceed to 6.7
chassis edge
photo 6.6E
Installing the Electronics Assembly
6.7
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” 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
photo 6.8b
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
photo 6.8a
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).
NOTE
12
photo 6.8c
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 this way, the proper spacing is
guaranteed when soldering the jacks together (photo 6.8c).
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 go on the
inside of the chassis. Tighten down the assembly.
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.
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 “G3a” and connect the
wire to the sleeve / ground terminal of the input 1 jack.
Proceed to 6.9
6.9 Installing and Wiring the Volume Control
Step 1 – Feed a red wire 8” in length starting from the volume control
location, behind the electronics assembly board, coming out between
the preamp tube and the speaker output jack.
Step 2 – Strip and tin the preamp tube end and connect the wire to pin
7 of the preamp tube.
Step 3 – Strip and tin the volume control end of the wire and connect
the wire to the middle lug of the volume control.
CAUTION
photo 6.9a
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.
Step 4 - 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 6.9a).
Step 5 – Strip and tin the end of the 3” black wire coming from pad “G3b” on the electronics
assembly and connect it to the volume control right far left terminal (photo 6.9a).
Proceed to 6.11
6.10 Wiring the Power Grounds from the PCB
photo 6.8a
Step 1 – Locate the black grounding wire at the upper left
corner of the electronics board (near the indicator lamp
assembly) 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 6.8a).
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 – Bend a small hook in this stripped and tinned end and connect this wire (along with
the wire from above) to the nearby terminal lug attached to the power transformer mounting
bolt nearest the fuse holder (photo 6.8a).
Step 5 – Solder both stripped ends to this lug.
Proceed to 6.9
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13
6.11 Installing the Indicator Lamp
Step 1 – With the indicator lamp in hand, remove
the nut from the bezel holder.
Step 2 – With the nut removed, remove the lamp holder.
Step 3 – Place the bezel holder through the corresponding
opening in the chassis.
Step 4 – Install the lamp holder on the threaded end of the
bezel holder.
CAUTION
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.
photo 6.11a
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.
NOTE
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.
Step 8 – Secure the nut by painting the exposed threads with fingernail polish (photo 6.11a).
Proceed to 6.12
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.
CAUTION
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.
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 its 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 the alignment of the strain relief (photo 6.12a).
Step 4 – With a pair of slip joint pliers, firmly squeeze the strain relief
into place around the power cord.
Step 5 – With these same pliers, grasp the strain relief and
feed the stripped end of the power cord into the corresponding
hole in the chassis.
Step 6 – 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).
NOTE
photo 6.12a
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
Photo 6.12b
14
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Step 7 – Once the strain relief is installed, tug on the power
cord to verify that it is indeed firmly mounted.
Proceed to 6.13
6.13 Installing and Wiring the Fuse Holder
Step 1 – Remove the nut from the fuse holder.
Step 2 – Insert the fuse holder into the corresponding chassis opening.
The rubber gasket should be situated on the outside of the chassis.
Step 3 – Reinstall the threaded nut on the fuse holder and tighten it
against the chassis.
Step 4 – Lock the nut down by painting the exposed threads with
fingernail polish (photo 6.13a).
Step 5 – Wire the AC main power source to the end terminal of the fuse
holder (photo 6.13a).
Photo 6.13a
By wiring the fuse holder as recommended, shock hazards associated with changing a fuse are
WARNING reduced because the source AC is at the far end of the fuse holder and not at the cap end.
Step 6 – Wire the power transformer's appropriate primary wire to the solder terminal on the
fuse holder nearest the faceplate (photo 6.13a).
CAUTION
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.
The correct wire choices as per the mains voltages are as follows:
CAUTION
If your mains
voltage is ...
100
117/120
220
230
240
then the wires to use are ...
wire #1 (to fuse holder)
black with blue stripe
white
black with yellow stripe
black with green stripe
black with red stripe
wire #2 (to power switch)
black
black
black
black
black
Step 7 – Once both wires are attached, neatly arrange excess wire close to the chassis.
Proceed to 6.14
6.14 Wiring the Power Switch
Step 1 – Solder the black wire from the AC power mains power cord
to the bottom terminal of the power switch on the back of the volume
pot.
Step 2 – Solder the black wire from the power transformer to the
remaining terminal of the power switch on the back of the volume pot
(photo 6.14a).
Proceed to 6.15
photo 6.14a
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15
6.15 Installing and Wiring the Speaker Jack
Step 1 – Install the 1/4” Switchcraft 11A jack into the
appropriate chassis hole. Place the lock washer 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
photo 6.15a
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 – Choose the appropriate output transformer tap wire for sleeve
tip
the impedance you are building this amp for (see below caution).
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.
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
6.16 Wiring the Rectifier Tube
photo 6.16a
photo 6.15b
photo 6.16b
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 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 apply solder
to pin 8 (photo 6.16b).
Step 3 – Strip and tin the two solid red wires from the power
transformer. Solder these to pins 4 and 6 of the rectifier tube
socket (photo 6.16b).
Step 4 – Trim the red wire from pad “d”. Strip and tin this wire and
connect it to pin 2 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
photo 6.16c
of the chassis. Strip, tin and solder to pin 8 of the rectifier tube
socket (photo 6.16b).
Step 6 - The remaining unused wires from the power transformer should be trimmed and
capped off with either electrical tape or preferably heat shrink tubing (photo 6.16c).
Proceed to 6.17
16
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6.17 Wiring the Power Output Tube
Step 1 – Trim, strip and tin the blue wire from the output
transformer. Solder this wire to pin 3 of the output tube socket
(photo 6.17a).
Step 2 – Trim, strip and tin the red wire from pad “e”. Solder this
wire to pin 4 of the output tube socket (photo 6.17a).
Step 3 - Trim, strip and tin the yellow wire from pad “f”. Solder
this wire to pin 8 of the output tube socket (photo 6.17a).
Step 4 – Trim, strip and tin the yellow wire from pad “h”. Solder
this wire to pin 5 of the output tube socket (photo 6.17a).
Step 5 – Neatly organize all wires tightly against the chassis.
Proceed to 6.18
6.18 Wiring the Preamp Tube
photo 6.17a
Step 1 - Trim, strip and tin the yellow wire from pad “g”. Solder
this wire to pin 8 of the preamp tube socket (photo 6.18a).
Step 2 – Verify that the red wire that runs from the center (wiper)
contact of the volume control is soldered to pin 7 of the preamp
tube socket (photo 6.18a).
Step 2 – Trim, strip and tin the yellow wire from pad “j”. Solder
this wire to pin 6 of the preamp tube socket (photo 6.18a).
Step 4 – Trim, strip and tin the yellow wire from pad “k”. Solder
this wire to pin 1 of the preamp tube socket (photo 6.18a).
Step 5 – Trim, strip and tin the red wire from pad “m”. Solder this
wire to pin 2 of the preamp tube socket.
Step 6 – Trim, strip and tin the yellow wire from pad “n”. Solder
this wire to pin 3 of the preamp tube socket (photo 6.18a).
Step 7 – Neatly organize all wires tightly against the chassis.
Proceed to 6.19
photo 6.18a
6.19 Installing and Wiring the Filaments
Step 1 – Trim, strip and tin the two green
wires from the power transformer. Solder
these wires on the two terminals of the
installed indicator lamp. Use the inside
mounting holes of the terminals (photo
6.19a).
Step 2 – Take the green 18awg stranded
wire and fold it in half. Tightly twist
together the two cut ends and chuck this
into an electric drill (photo 6.19b).
Step 3 – Wrap the other end around a
screwdriver and pull tightly the wire tightly
between the drill and screwdriver (photo 6.19c).
photo 6.19b
photo 6.19a
photo 6.19c
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17
Step 4 – Slowly engage the drill, twisting the wire tightly and
evenly together (photo 6.19d).
Step 5 – Unwind about 1” of the cut ends
of the twisted wire. Strip and tin these
ends and solder them to the indicator lamp
terminals (photo 6.19a).
Step 6 – Measure approximately 4” of the
twisted wire from the indicator lamp and
cut. Unwind about 1” from the cut ends of
photo 6.19d
this twisted wire. Strip and tin these ends
and connect to pins 2 and 7 of the power
tube socket. Do not solder just yet.
Step 7 – Unwind about 1” of the cut ends of the remaining twisted
wire. Strip and tin these ends and connect them to pins 2 and 7 of
the power tube socket. Apply solder to pins 2 and 7 of the power
tube socket (photo 6.19e).
Step 8 - Measure approximately 6” of this twisted wire from the
power tube socket and cut. Unwind about 1” from the cut ends of
this twisted wire. Strip and tin these ends and connect to pins 9 and
4/5 of the preamp tube socket. Do not solder just yet.
photo 6.19e
Step 9 – Take the two 100 ohm resistors and twist the
two leads together (6.19f).
Step 10 – Bend the end of the other two opposite
leads of the resistors away from each other (6.19g).
Step 11 – Connect these two bent resistor ends to pins
photo 6.19f
9 and 4/5.
Step 12 – Apply solder to pins 9 and 4/5 (photo 6.19h). photo 6.19g
Step 13 – Trim the twisted ends of the resistors to half
length. Bend a small loop in the twisted ends.
Step 14 – Cut a 3” length of black wire. Strip and tin
both ends.
Step 15 – Solder one end of this black wire to the loop
of the two resistors (photo 6.19h).
Step 16 – Solder the other end of this black wire to the solder tab
mounted to the screw of the preamp tube (photo 6.19h).
Proceed to Chapter 7
photo 6.19h
18
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7 Final Assembly
7.1 Installing the Chassis Mounting Bolts and Chassis
Step 1 – Press the two truss bolts into the cabinet holes.
Step 2 – Mount the chassis onto the bolts, holding the chassis against the cabinet top.
Step 3 – Install the two #10 KEPS nuts, one on each bolt, and loosely tighten chassis against
top of cabinet.
Step 4 – Slide chassis to rear of cabinet, away from speaker.
Step 5 – Press back panel into position, pushing the chassis against the panel. This will
properly align the chassis with in the cabinet and provide good contact with shielding foil.
NOTE
Proper alignment of chassis within cabinet is when the chassis contacts the back panel
shielding tape without distorting the flatness of the back panel.
Step 6 – Place back panel to the side and firmly tighten chassis into the cabinet.
Proceed to next step
7.2
Installing AC Power Cord Clamp
Step 1 – Properly align the 5/16” nylon cable clamp
around power cord (photo 7.2A).
Step 2 – With a #8 x 5/8” screw, secure the cable
clamp and power cord to the inside cabinet wall.
(photo 7.2B).
Proceed to Chapter 8
photo 7.2A
photo 7.2B
TubeDepot.com
19
8 Testing
are almost finished. And although the first temptation is to plug up the amp and
8.1 You
turn it on, I want to caution you to instead take the time and review all your
connections. This will be time well spent as it ties together all the construction steps. Any
errors are more likely to stand out at this time. It is not uncommon to find two or three errors.
After verifying all of the above connections are correct, read through all of the following
steps before completing any of them. Once you have finished reading these steps, it is time
to begin.
Step 1 - Install a 2A, fast blow fuse into the fuse holder.
WARNING
CAUTION
When changing or installing a fuse, always remove the AC source by unplugging the amp.
Never use fingers to remove or insert a fuse into a fuse holder. Instead, use the fuse cap to
hold the fuse when removing or inserting into the holder.
Use of any fuse larger than 2A is not recommended and could cause severe and costly
equipment damage in case of an internal component failure.
Step 2 – With the amp unplugged and no tubes installed, turn on the amplifier's power
switch. The power switch will remain on until all tests are finished.
Step 3 – Plug the amp's AC power cord into AC power at the wall.
NOTE
I personally recommend using a variable AC with separate current and voltage meters. This
allows bringing the voltages up very slowly and provides more accurate monitoring capabilities.
NOTE
If you are uncomfortable with just turning on the amp and watching for smoke, I recommend
building an inexpensive Dim-Bulb tester to monitor and control current flow into the amp. A
quick internet search on “Dim Bulb tester” will give several diagrams and plans.
CAUTION
WARNING
It is good practice to use a power strip with a circuit breaker and an on/off switch between the
wall power and the amplifier power cord as an improved electrical safety measure.
In case of any troubles, quickly disconnecting the power cord from the wall (or turn off the
power strip). You should not touch the amp or the amp's power switch until the amplifier's
power cord is no longer connected to AC wall power.
Step 4 – The panel indicator should illuminate. Monitor for any unusually smoke or smells or
a blown fuse or hot power transformer. If anything unusual occurs, disconnect power
immediately and review connections.
Step 5 – If there is nothing unusual after a couple of minutes, remove AC power by
disconnecting the AC power cord from the AC source.
Step 6 – With the amp disconnected from power, install the rectifier tube.
Step 7 – Plug the amplifier's AC power cord into the AC power source at the wall.
Step 8 – The panel indicator should illuminate. Visually verify that the filament inside the
rectifier tube is glowing. Monitor amplifier for any unusual smoke or smells or blown fuse. If
anything unusual occurs, disconnect power immediately and review connections.
NOTE
20
Within a minute or two, the rectifier will have heated up and provided a slowly increasing high
voltage to the power supply. This voltage will have properly formed the high voltage filter caps.
TubeDepot.com
Step 9 – With your multimeter on the 500 volt range, carefully
connect the meter's black lead to chassis ground and the red
lead to the positive end of C6 (B+). The voltage here should
be something close to +450 volts (photo 8.1A).
WARNING
Whenever testing voltages, it is recommended to keep your free hand off of the chassis. In
this way, there isn't a path for significant current to flow through the body to ground in case the
measuring hand accidentally comes in contact with high voltages.
Step 10 – Remove AC power by
disconnecting the AC power cord
from the AC source.
Step 11 – Install the preamp tube.
Step 12 – Plug the amplifier's AC
power cord into the AC power
source at the wall.
Step 13 - The panel indicator should
illuminate. Monitor for any unusual
Photo 8.1A
photo 8.1B
smoke or smells or blown fuse.
If anything unusual occurs, disconnect power immediately and review connections.
Step 14 – Let the amplifier warm up for 2 minutes. With a multimeter on the 20 volt range,
carefully connect the meter's black lead to chassis ground and the red lead to the positive
side of C3. If C3 is not installed, the red lead can be connected to pad “n” instead. The
voltage here should be close to +1.8 volts (photo 8.1B).
NOTE
The presence of voltages at steps 14 & 15 indicates that the two halves of V1 are correctly
sourcing current.
Step 15 – Move the red lead to the positive side R7 (pad “g”). The voltage here should be
close to +1.8 volts.
Step 16 – If these measurements are correct, remove the AC power by disconnecting the AC
power cord from the AC source.
Step 17 – Install the power tube.
Step 18 – Connect speaker to output jack.
Step 19 – Turn volume to minimum position, leaving the
amplifier power switch to “on”.
Step 20 – Plug the amplifier's AC power cord into the AC power
source at the wall.
Step 21 – The panel indicator should illuminate. Monitor for any
unusual smoke or smells or blown fuse. If anything unusual
photo 8.1C
occurs, disconnect power immediately and review connections.
Step 22 – Let the amplifier warm for 2 minutes.
With a multimeter on the 200 volt range, carefully connect the meter's black lead to chassis
ground and the red lead to the positive side of C4. The voltage here should read close to +22
volts (photo 8.1C).
NOTE
The presence of voltage at step 22 indicates that V2 is correctly sourcing current.
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21
Step 23 – If all these measurements are within specifications,
and the speaker is connected, and there no signal source
connected to either input, turn up the volume control and
listen for a low level hiss from the speaker. There will be a slight hum, but anything drastic
indicates wiring troubles.
Step 24 – If the above hiss is heard, turn the volume control back to minimum and connect a
signal source into input 1.
NOTE
A signal source can be a guitar or high impedance microphone or even a low level CD or MP3
player. A speaker output from another amp is not recommended.
Step 25 – Turn up the volume on the amp and the signal source (most likely a guitar or
harmonica microphone) and verify that the signal is coming from the speaker.
Step 26 – If everything checks good, turn off amp and install the back panel.
Step 27 – Now the time has come to rock out … your amp is done!
The End
22
TubeDepot.com
9 Schematics
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23
24
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26
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10 Cool Modifications
Once you have the amp working and sounding good, here are a few ideas to “shape” the
tone to suite your tastes.
1. Change both C1 and C2 to .01ufd or .0047ufd to reduce low frequency response at
high gain settings. Gives the amp the ability to “cut through” better.
2. Install 22ufd/450v caps in C8 and C9 positions - tightens power supply and provides
quicker dynamics.
3. Experiment with 22ufd/50v cap in C3 position - increases gain with it installed.
4. Change out 6V6 for an EL84 by fabricating your own cover plate adapter and installing
a 9 pin tube socket – allows installing EL84s vs. 6V6.
5. Change out 6V6 for 6AQ5/6005 by fabricating your own cover plate adapter and
installing a 7 pin socket – allows installation of 6AQ5s vs. 6V6.
6. Change out 6V6 with 5881. It is recommended to disconnect the 5.0V filament and
use a solid state rectifier. This additional power transformer over head will be needed
for the increased 6.3V filament requirements of the 5881. Additionally, the filter caps
will have to be upgraded to +500V.
7. Install solid state rectifier in place of tube rectifier – tightens up dynamics and power
output. Filter caps must be upgraded to +500V types.
8. Run amp without neg. feedback altogether by disconnecting feedback line from
speaker output jack – provides much more overall gain and distortion with the volume
up.
TubeDepot.com
27
A
Appendix A
Resistor and Capacitor Codes
Most electronic components are so small that printing the actual values, ratings and
tolerances on the individual component is nearly impossible. Therefore, codes were invented
early in electronic history and printed on the components to describe what they were. Many
of these codes are still in use today.
Below I've listed some of the more common codes that you are likely to come across while
building this project.
How to Identify Power Ratings and Resistor Value Color Codes.
This project uses different types of resistors. The diagrams below will assist you in locating
and identifying resistor values, tolerances and ratings for the various circuit requirements for
your project.
Resistor Power Ratings
Not only are resistors graded by their values but also by their power ratings. Power ratings
are determined by how much heat (power) can be safely dissipated by the resistor. Higher
ratings are usually indicated by larger sizes.
Below are photos and descriptions of the various resistors used in this project.
Carbon Composition 1/2W
Carbon Film 1/2W
Metal Oxide 1W
Metal Oxide 2W
Metalized Film 1/2W
Metal Oxide 3W
Carbon Composition 1W
28
TubeDepot.com
Resistor Value Color Codes
Resistor Types
Carbon Film
Metal Oxide
Carbon Composition
1st Digit
Color
Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Gray
White
Digit
0
1
2
3
4
5
6
7
8
9
Color
Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Gray
White
Tolerance
Multiplier
2nd Digit
Digit
Color
Multiplier
0
1
2
3
4
5
6
7
8
9
Black
Brown
Red
Orange
Yellow
Green
Blue
1
10
100
1,000
10,000
100,000
1,000,000
Color
Digit
3rd Digit
Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Gray
White
0
1
2
3
4
5
6
7
8
9
Silver
Gold
Color
Tolerance
None
Silver
Gold
Red
Brown
+/- 20%
+/- 10%
+/- 5%
+/- 2%
+/- 1%
.01
.1
Metal Film (1% )
TubeDepot.com
29
How to Read Capacitor Value Codes
This project uses several different kinds of capacitors. Some of these capacitors have their
values and voltage ratings printed on them, others use numerical codes. The diagrams below
will assist you in locating and identifying capacitor values, tolerances, and voltage ratings for
the various circuit requirements for your project.
Cornell-Dubilier Silver Mica – high quality / high accuracy picofarad cap
1st line:
2nd line:
250 +/- %5
500V SM
= direct value in pfd (250pfd); tolerance 5%
= voltage rating (500V); batch code
Sprague “Orange Drop” 715 series – Vintage style film & foil
polypropylene capacitor.
1st line:
2nd line:
715P600V
104J 0821
104 = .1ufd
103 = .01ufd
102 = .001ufd
= 715 series; rated at 600V
= value in pfd (104 = 10 and 4 zeros pfd);
tolerance (J = +/- 5%); batch code
223 = .022ufd
222 = .0022ufd
473 = .047ufd
472 = .0047ufd
Xicon Metalized Polypropylene – Warm tone, small size
1st line:
F104K d
2nd line:
630MPP 1
104 = .1ufd
103 = .01ufd
102 = .001ufd
= value in pfd (104 = 10 and 4 zeros pfd);
tolerance (K = +/- 10%)
= voltage rating (630V);
construction (MPP = metalized polypropylene)
223 = .022ufd
222 = .0022ufd
473 = .047ufd
472 = .0047ufd
Sozo Film and Foil – Vintage style film & foil polypropylene
capacitor, axial leads
1st line:
2nd line:
3rd line:
30
TubeDepot.com
104 = .1ufd
103 = .01ufd
102 = .001ufd
684K = value in pfd (684 = 68 and 4 zeros pfd);
tolerance (K = +/- 10%)
160V = voltage rating (160V)
0834R = batch / date code
684 = .68ufd
223 = .022ufd
222 = .0022ufd
473 = .047ufd
472 = .0047ufd
B Appendix B
Soldering Hints
Anyone working in electronics should learn how to solder well. Thankfully it isn't hard, it just
takes practice and having the proper tools. Once you are able to solder well, your projects
will be more professional and more reliable.
Refer to our video “How To Solder” for detailed explanations.
http://www.youtube.com/watch?v=cIDydYIVTqU&feature=channel_page
But before you get started, here are a few safety tips that should be followed:
– Fumes from soldering can be harmful therefore it is important to always have adequate
ventilation.
– Wear appropriate clothing when working around hot, molten solder. Never wear shorts
or open toes shoes.
– protect hands and equipment from burns by using a soldering iron holder. An
improperly stored soldering iron is a fire hazard
– Do not eat, drink, or smoke while you are soldering. Limit exposure to lead.
– Wash hands often when soldering.
– Wear safety glasses when soldering.
Purpose of Soldering
Soldering is used to bond two or more metals together. By applying heat to a connection
and feeding solder into this connection, the solder will melt and flow around the metals. A
small surface amount of each of the metals will additionally melt and inter-mix with the liquid
solder forming an alloy. This connection is called an intermetallic bond and the two metals,
when properly soldered together, act as if it they were one solid piece.
Importance of Proper Soldering
Proper soldering is the basis for faithful equipment operation. A good solder connection is
physically strong and electrically reliable. A poorly soldered connection will have intermittent
operation which can cause electrical damage to neighboring components. At the very least, a
bad solder connection will create an unpleasant audible experience. Therefore the
importance of good soldering skills cannot be over emphasized. Your sound will rely on it.
Basic Soldering Rules
The following are some basic soldering rules that if followed, will result in a reliably soldered
connection every time:
1. Make sure the surfaces to be soldered are clean and free of corrosion. A dirty, greasy,
or oxidized surface will not accept solder properly, creating an intermittent solder
connection.
2. Establish a firm mechanical connection of the components prior to soldering. Solder
should only be used to develop an electrical connection and not a mechanical one.
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3. Insure that the soldering tip is clean prior to any
soldering. A clean solder tip is one wiped lightly across
a damp sponge to remove oxides prior to use. It is essential for maximum heat
transfer that there are few contaminants on the tip.
4. When applying the soldering iron to a connection to be made, it is important to lay the
tip in such a position that the maximum surface area of the tip is presented to the
connection. In this way, the maximum heat is transferred to the connection in the
minimal amount of time.
5. Apply solder to the work and not the iron. In this way, a properly heated connection will
readily accept the solder, further reducing the chances for unreliability.
6. Use only clean, good quality, rosin core solder. Poor quality or dirty solder will not melt
smoothly and will deposit contaminants into the connection, making it weak.
7. Use only the amount of solder needed to complete the connection. Use too little solder
and the connections is compromised where as too much solder runs the risk of
accidentally contacting neighboring connections.
8. Finish the connection by removing the soldering iron quickly. It is important to apply
heat only for as long as it needed to properly flow the solder. Any additional heat runs
the risk of overheating the parts being soldered.
9. Do not move the parts of the connection while the solder is hardening. It is important
that everything stays totally still until the solder has fully set because any movement in
the parts while the solder is in a plastic state will result in a weak, unreliable, and
cracked connection.
10. Clean any rosin residues from freshly made connections. Rosin residues can trap dirt
and dust that could weaken a connection and possibly create arcing conditions.
Isopropyl or ethel alcohol and a stiff bristled brush are good for this.
Sequence of Events to Make a Good Connection
1. Establish a good mechanical connection of the components prior to soldering.
2. Place the tip of the iron firmly against the connection to be soldered.
3. Let connection reach soldering temperature (usually within 1 to 2 seconds).
4. Feed solder into the point where the soldering iron tip meets the connection, not on to
the tip of the soldering iron.
5. Feed an adequate amount of solder into the connection for the solder to flow around
the components to be joined.
6. When adequate amount has been reached, remove solder and iron simultaneously.
7. Do not move connection or components until solder has solidified.
8. Clip off any excess wire lead(s).
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C Appendix C
Amplifier Care, Feeding, and Applications
Now that the amp is together here are a few good hints to keep it up and running and you
safe and happy:
– Only plug this amp into properly grounded (three prong) AC receptacles.
– Do not cut off the third prong of the power cord plug thus defeating its safety feature.
WARNING
Keith Relf of “The Yardbirds”, Leslie Harvey of “Stone the Crows”, and John Rostill of “The
Shadows” all died of electrocution while playing their guitars (Leslie Harvey while on stage).
Proper grounding is more than just important … it can be life or death!
Only plug this amp into the properly wired AC voltages.
Do not expose this amp to high levels of moisture such as rain or spilled liquids.
Avoid placing any beverages on the cabinet.
When ever changing tubes or cleaning this amp, disconnect the amp from the AC
power source and allow amp to cool for 10 min. before beginning.
– It is recommended that the amp is only plugged to AC power when the amp is being
used. Otherwise, it should be left unplugged from AC voltages.
– Avoid exposing this amp to elevated temperatures such as heaters or hot cars or
garages. The expansion and contractions of these temperatures will put undo stress
on all the solder connections, possibly damaging them.
– Always provide adequate ventilation for the tubes and amplifier. An air space of 6” or
more is recommended between the amp and any other object(s), especially around the
rear of the amp. It is a good idea to keep the amp as cool as possible.
–
–
–
–
Amplifier Feeding
As with any tube amp, the choice of tubes will effect the overall tone of the amp. And of
course, some tube choices are more dramatic than others. Therefore, I encourage everyone
to shape the tone of this amp to suit their tastes through the use of different tubes. Below is a
short list of tubes that can be used for adjusting tone performance without modifying the amp.
Preamp tubes:
– 12AX7A / ECC83 / ECC803 / 7025; (high gain – amplification factor = 100)
– 12AD7; (high gain – amplification factor = 100)
– 12AT7 / ECC81; (high gain – amplification factor = 70)
– 12AY7; (med gain – amplification factor = 40)
– 12AU7 / 5814 / 6189 / 5963 / ECC82; (low gain – amplification factor = 17)
– 12AZ7; (med gain – amplification factor = 60)
– 12DW7; (mixed gain – amplification factor, first triode = 100; second triode = 17)
– 5751; (high gain – amplification factor = 70)
Power tubes:
– 6V6GT
- 5871
- 7408
- 7184
Rectifier tubes:
– 5Y3GT
- 5AX4
- 5CG4
- 5R4
- 5T4
– 5V4
- 5Z4
- 5AR4
- GZ30
- 6106
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Applications
The laboratory environment is nice, but life experiences better determine success levels.
Therefore the true test of a good amp is how well it performs “in the field”. The following are
some of my favorite field proven gigging and recording hints.
– Run this amp wide open! Let it breath, let it sing. It wants to be heard.
– With the amp wide open, control the level of distortion with the guitar's volume control.
– Try recording this amp by putting a microphone in front, slightly off axis of the speaker
to get a crunchy, bluesy tone. Relocate the microphone to directly in front to get an
upfront rock tone.
– Instead of one, try recording with two microphones, one in front (straight phase) and
another in back (reverse the phase). This will make the amp sound huge when
recorded!
– Run the amp into a different cabinet (ie 2x12, 4x12, 4x10). It is surprising how different
speaker set ups will respond to 5W. Just set microphones to taste and enjoy.
– Record the amp in the bathroom close to the tub. Tubs ring wonderfully when excited.
– A little slap back echo goes along way so try a delay pedal between the guitar and
amp.
– A vibrato or tremolo pedal in front is perfect for soulful coolness.
– Run an overdrive pedal set clean in front of the amp. Now crank up the pedal's output
and hit the amp hard with this signal. I love this arrangement!
– Harp players can get control of feedback (as well as tone shaping) by putting an EQ
pedal between the harp microphone and the amp.
– Guitar players can benefit from an EQ pedal in front as well. Just a little more shaping
can make everyone happy.
– The low end response can be maximized by situating the amp's cabinet as firmly
against the floor as possible.
– Run your guitar / harp microphone into the #1 input and then come out of the #2 input
of this amp and go into the front end of a different amp. This way you can run two
amps at the same time. The sound of this amp mixed with another is very good.
– Connect the output of this amp to a speaker load box with a line out and this amp
becomes a great preamp in which to drive another amp or straight to the board.
– Run a vocal microphone (through the appropriate impedance matching devices) and
record the most deliciously distorted vocals ever. No modeling can touch this sound.
– Install a solid state rectifier and get an extra watt of power and an animated dynamics
in tone.
– Exchange the 6V6 with a 5881 for a more expansive sound scape. It is best to only
run the 5881 when using the solid state rectifer.
–
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D
Appendix D
Templates
Appendix D1 is the cabinet drilling template …..............................................................
Appendix D2 is the chassis drilling template – PCB and Turret Boards …............................
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