Mod 101 User manual

1Copyright © 2015 by modkitsdiy.com
Use these instructions to learn:
How to build a tube amp.
How to bias a tube amp for 6L6GC or EL34 power tubes.
Some modifications for altering the tone of a tube amp.
This tube guitar amplifier circuit is basic and classic. It can produce warm clean tone at low volume and
rich overdrive distortion at higher volume.
1 5/
16"
ON
OFF
POWER STANDBY BASS TREBLE VOLUME INPUT
0 10
5
2 8
3
4 6
7
1 9
0 10
5
2 8
3
4 6
7
1 9
0 10
5
2 8
3
4 6
7
1 9
MOD 101
TUBE AMP KIT
MOD 101 GUITAR AMP KIT (K-MOD101)
www.modkitsdiy.com

2
TABLE OF CONTENTS
TOOL LIST …………………………………………………………………………...3
PARTS LIST …………………………………………………………………………...4
SAFETY …………………………………………………………………………...6
SOLDERING TIPS …………………………………………………………………...7
WIRING TIPS ……………………………………………...................................8
HARDWARE FASTENING TIP …………………………………………………...9
STEP BY STEP ASSEMBLY INSTRUCTIONS …………………………………...9
Section 1 – Mounting of Top Components …………………………………...9
Section 2 – Mounting of Front Components ………………………………….12
Section 3 – Mounting of Rear Components ………………………………….13
Section 4 – Mounting Internal Terminal Strips and Passive Components ….14
Section 5 – Solder the Filter Components ………………………………….16
Section 6 – Connect the Front Mounted Components ………………….18
Section 7 – Connect TR2 to the Impedance Selector Switch ………………….20
Section 8 – Connect the Tube Sockets ………………………………….22
Section 9 – Connect the Terminal Strip Interconnects ………………….23
Section 10 – Connect the Tube Filaments ………………………………….23
Section 11 – Insert the Strain Relief and Connect the Power Cord ………….24
Section 12 – Fasten the Rubber Feet to the Chassis Cover ………………….25
Section 13 – Fasten the Chassis Cover to the Chassis Box ………………….25
Section 14 – Set the Bias of the Power Tubes ………………………….26
Section 15 – Fasten the Steel Cage to the Chassis Box ………………….28
Section 16 – Modifications ………………………………………………….29
PARTS LIST DRAWINGS (4)
There are four parts list drawings separated from these instructions to help you find
each part and identify it.
ASSEMBLY DRAWINGS (25)
There are 25 assembly drawings separated from these instructions to help you with each
step of the assembly.

MOD 101 GUITAR AMP KIT – BACKGROUND
The MOD 101 Guitar Amp Kit was designed for anyone who is interested in building their own tube guitar
amplifier head and learning some simple circuit modifications that can be used to tailor the sound to better suit
their tonal preference. The modifications are instructions and supplied parts that allow you to build 32
variations of the amp circuit.
The amp is meant for concert stage volume (up to 60 Watts). It is equipped with an impedance selector
switch, giving you the flexibility to use it with the speaker cabinet of your choice. (We recommend using it
with a speaker cabinet that has an overall wattage of at least 100W). Use 16 AWG speaker cable to connect
from the amplifier to your speaker cabinet. Set the amplifier switch to match the overall impedance of the
speaker cabinet.
3
TOOL LIST
Wire Strippers
Needle Nose Pliers
Cutting Pliers
Desoldering Pump
Solder (60/40 rosin core)
Soldering Station
Phillips Head Screwdrivers
Slotted tip screwdrivers (3mm tip)
Digital Multimeter (DMM)
Alligator Clip Test Leads (to fit DMM)
Channellock Pliers (or similar type)
Miniature Round File (fine cut)

PARTS LIST
Please see the parts list drawings for help with finding and identifying each part
along with corresponding part numbers.
RESISTORS:
Description Quantity
1Ω 1/2W 2
1Ω 5W 1
47Ω 1/2W 1
360Ω 10W 1
470Ω 1/2W 3
820Ω 1/2W 2
1kΩ 1W 1
1kΩ 5W 2
1.5kΩ 1/2W 2
2.4kΩ 1/2W 1
2.7kΩ 1/2W 1
4.7kΩ 1W 1
5kΩ 5W 1
6.8kΩ 1/2W 2
20kΩ 1/2W 1
22kΩ 1/2W 1
68kΩ 1/2W 2
82kΩ 1W 1
100kΩ 1/2W 1
100kΩ 1W 3
220kΩ 1/2W 2
220kΩ 1W 2
1MΩ 1/2W 4
TERMINAL STRIPS:
Description Quantity
3 lug terminal strip (vertical) 5
3 lug terminal strip (2nd lug common) 1
4 lug terminal strip 2
5 lug terminal strip 1
6 lug terminal strip (no common) 2
6 lug terminal strip (2nd lug common) 3
8 lug terminal strip 1
HARDWARE:
Description Quantity
#10 screws 8
#10 lock washers 6
#10 hex nuts 8
#8 screw 4
#8 self-tap screws 8
#8 hex nuts 4
#6 screws 22
#6 lock washers 20
#6 locking lugs 4
#6 hex nuts 22
#4 screws 4
#4 lock washers 4
#4 hex nut 4
TUBES:
Description Quantity
12AX7/ECC83 1
12AT7/ECC81 1
6L6GC 2
EL34 2
TRANSFORMERS:
Description Quantity
Power Transformer 374BX 1
Output Transformer 1650P 1
4
CAPACITORS:
Description Quantity
250pF 500V 1
500pF 500V 1
.001µF 630V 1
.022µF 630V 2
.047µF 630V 1
.1µF 630V 4
22µF 50V 2
22µF 500V 4
80µF 450V 2
220µF 50V 1

MISCELLANEOUS PARTS:
Description Quantity
Solid state diode 1N4007 3
250kΩ audio pot 2
1MΩ audio pot 1
25kΩ linear pot 1
Chicken head knob 4
Impedance switch & output jack 1
9 pin miniature tube socket 2
Octal tube socket 2
Tube clip 2
Rubber Grommet 5
Strain Relief 1
Input jack 1
Purple jewel 1
Power switch (DPDT) 1
Standby switch (SPST) 1
2A fuse 1
Fuse holder 1
Light bulb 1
Lamp holder 1
Handle with mounting hardware 2
Rubber feet 4
Power cord 1
Steel chassis box and cover 1/each
Steel cage 1
Labels 1 set
Green 20 AWG wire 10 feet
Red 22 AWG wire 20 feet
5

6
DANGER
HIGH VOLTAGE
MAY BE PRESENT
ON FILTER CAPACITORS
DO NOT TOUCH!
SAFETY
Tube amps operate at high voltages that have the potential to injure and kill. Please remember the following
when working on this project.
Only work on the amp when you are wide awake and sober.
Do not plug the amp in until you have gone through all of the instructions, checking and re-checking
each step.
Do not turn the amp on until you have connected it to a speaker cabinet.
Be aware that tubes become very hot when the amp is on and can take up to 10 minutes to cool down
after power is turned off.
Work in a ventilated area when soldering.
Always follow the one hand rule when working with an amp that is connected to power or may have
voltage present. (Any amp that has been plugged in at one time, may have high voltage present).
ON STANDBY
The one hand rule (pictured below): is a safety precaution for working on an amp that is
plugged in or could potentially have high voltages present. Using alligator clips with your
DMM, clip the ground side to the chassis and use the other side to probe at various test points
with one hand. This prevents a fatal shock which can result from current passing through the
heart. (Many people even put their other hand in their pocket or behind their back).
Always probe the amp for dangerous voltages at several test points before working on it, even if it has been turned
off and unplugged for months.
Test points include:
Both Standby Switch Terminals
Each positive end of polarized filter caps
If you smell or see smoke, hear something pop, or the chassis becomes too hot to touch, turn off
power and unplug immediately.

SOLDERING TIPS
1. Bend the component lead
and wrap it around the
connection point.
2. Wrap the component lead
so that it can hold itself to the
connection point.
3. Heat up both component
lead and connection point with
the soldering iron.
4. Apply solder to both
component lead and
connection point.
2. Apply fresh solder to mix in
with old solder joint
1. Heat up old solder joint
with the soldering iron.
3. Use a de-soldering tool to
remove the old solder joint
while it is heated.
De-Soldering Tip
7
It is important to make a good solder joint at each connection point. A cold solder joint is a connection that
may look connected but is actually disconnected or intermittently connected. (A cold solder joint can keep
your project from working.)
Follow these tips to make a good solder joint. Take your time with each connection and make sure that all
components are connected and will remain connected if your project is bumped or shaken.
Bend the component lead or wire ending and wrap it around the connection point.
Make sure it is not too close to a neighboring component which could cause an
unintended connection.
2. Wrap the component lead so that it can hold itself to the connection point.
Touch the soldering iron to both the component lead and the connection point allowing both to
warm up just before applying the solder to them.
Be sure to adequately cover both component lead and connection point with melted solder.
Remove the soldering iron from your work and allow the solder joint to cool. (The
solder joint should be shiny and smooth after solidifying.)
Cut off any excess wire or component leads with cutting pliers.
Clean the soldering iron's tip by wiping it across the wet sponge again after making the
solder joint.

WIRING TIPS
There are two different gauges of stranded wire included with the kit. Use 22 AWG wire unless noted
otherwise in the instructions. The lower AWG (American Wire Gauge) number signifies a thicker gauge of
wire, which can handle more current. (It is important to use the thicker gauge wire where specified in the
instructions.)
8
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
20AWG
22AWG
Because of the electro-magnetic
properties of current traveling through a
wire, there are wiring conventions used
when making wire connections.
A) Twist the wires together where
indicated in the instructions.
B) If two wire paths intersect, try to
have them cross over each other as
perpendicular as possible. (You should
follow the path of the wires shown in
the instructions).
A) Twisted Wires
B) Perpendicular
Intersection
Measure the wire by running it along its actual path (shown in the drawings) and then cutting it with
your wire cutters at a length that will give it a little bit of slack after stripping off the insulation and
soldering.
It is important not to make the wires too long.
Be careful not to strip away strands of wire when you remove the insulation at the end of wires.
Be careful not to burn the insulation of nearby wires with the soldering iron.
With the terminal strips used in this kit, you might want to connect the wires to the lower holes
and components to the upper holes. (Doing this can make it easier to change components for
modification).
5W 1K
5W 1K
Wires connected to lower terminal holes.
Components connected to upper terminal
holes.

STEP BY STEP ASSEMBLY
Please refer to the respective drawings for each section. We recommend browsing over the instructions and
looking at all drawings once before actually beginning to assemble the kit.
HARDWARE FASTENING TIP
When fastening components with mounting hardware (screws, lock washers, and hex nuts), the lock washer and
hex nuts should be fastened on the other side of the chassis from the head of the screw in the order pictured
below.
SECTION 1 – Mounting of Top Components
Please refer to Drawings 1 – 6. Find your chassis box. Drawing 1 identifies the names of
components that you will be mounting to the top of the
chassis box.
COLD HOT
Step 2
Drawing 2 shows where to stick the bias label. Make sure to line up the hole in the
sticker with the hole in the chassis box.
Step 3 – Mount the bias pot
Drawing 3 shows where to mount the bias pot. Bend down the tab on the top of
the pot for a better fit against the chassis top. Make sure the solder lugs of the pot
are directed toward the front of the chassis. (Turn the shaft all the way to cold).
25KL
Chassis Front Bent back mounting tab
Step 4 – Mount the rubber grommets
Drawing 3 shows where to mount the five rubber grommets. Squeeze the grommet
into the hole and push it into place with your fingers.
9
Chassis
Screw Head
Lock Washer Hex Nut
Component Mounting
Bracket
(5)
Step 1
Use a fine cut miniature round file to very lightly file away
the paint coating only from the inside edge of each chassis
hole.
(The chassis provides the ground connection for many
components so it is important that the inner edge of
these holes are not insulated by the paint coating).

10
(2) (4)
(4)
(4)
Step 5 – Mount the 9 pin miniature tube sockets
Drawing 3 shows where to mount the two 9 pin miniature
sockets. Make sure that pins 1 & 9 face away from the rear edge
of the chassis. (Use #4 hardware).
Step 6 – Mount the octal tube sockets and tube clips
Drawing 3 shows where to mount the two octal sockets along with their tube clips. Make sure that pins 1 & 8
face away from the rear edge of the chassis. (Use #6 hardware)
(2)
(4)(2)
(4)
(2)(2)
Use locking lugs in place of lock washers for the
mounting screws which face away from the rear
chassis edge.
The mounting holes of the tube clip are placed
over those of the octal socket. The screws are
then placed through both sets of mounting holes.
Step 7 – Mount both side handles
Mount both handles to the sides of the chassis box using their supplied #8 hardware. (Doing this step will
help you flip the chassis when mounting the two heavy transformers).
TOP
.25
"
Mount both side handles.
(4)
(4)
(2)
1
2
3
4
5
6
7
8
Chassis Rear

Step 8 – Mount the Output Transformer
Remove the 1650P output transformer from its packaging. Drawings 4 and 5 show where to mount the
output transformer.
A) Cut off the blu/yel and brn/yel wires as described on the drawing.
B) Place the transformer on its side and push the wires (one at a time) through their respective grommet holes
as indicated on the drawing.
C) Slowly tilt the transformer upright so that the mounting holes line up with the transformer feet, while
continuing to push each bundle of wires through the grommet holes. (Be careful not to dislodge the rubber
grommets).
11
Use #10 mounting hardware.
(4) (4) (4)
#
1
0
#
1
0
#
1
0
#
1
0
1650P
(1)
Use #10 mounting hardware
and two #6 locking lugs.
(4) (2) (4) (2)
374BX
(1)
Step 9 – Mount the Power Transformer
Remove the 374BX power transformer from its packaging. Drawings 5 and 6 show where to mount the
power transformer.
A) Cut off the blu/yel, wht/blk, blk/red, brn/yel, yel, yel, and yel/blk wires as described on the drawing.
B) Place the transformer on its side and push the wires (one at a time) through their respective grommet holes
as indicated on the drawing.
C) Slowly tilt the transformer upright so that the mounting holes line up with the transformer feet, while
continuing to push each bundle of wires through the grommet holes. (Be careful not to dislodge the rubber
grommets).
D) Use #10 mounting hardware and two #6 locking lugs in place of regular lock washers on the two inside
screws. (You can cut a slot in the rings of both locking lugs and stretch them slightly to fit the #10 screws).
Cut a slit in the locking lugs in
order to fit the #10 screws

12
Step 10 – Mount the Filter Cap Terminal Strips
Drawing 6 shows where to mount the 5 terminal strips which will be used for mounting the filter capacitors.
Use #6 hardware.
(5) (5) (5)
(5)
Step 11 – Mount the Danger Label
Drawing 6 shows where to mount the danger label. This sticker is mainly used to scare people away from the
amp if you have the steel cage removed. (When playing the amp, keep the steel cage fastened for safety).
DANGER
HIGH VOLTAGE
MAY BE PRESENT
ON FILTER CAPACITORS
DO NOT TOUCH!
SECTION 2 – Mounting of Front Components
Please refer to Drawing 7.
Step 1 – Mount Faceplate Label
Drawing 7 shows the faceplate label. Make sure and line up each hole in the sticker with each hole in the
chassis front and carefully stick it to the chassis.
Step 2 – Mount the Lamp Holder
Drawing 7 shows where to mount the lamp holder. Be sure to mount it so that its solder lugs point towards
the bottom opening of the chassis box. (Once the lamp holder is mounted you may screw in the bulb and then
the jewel).
Step 3 – Mount the Power Switch and Standby Switch
Drawing 7 shows where to mount the power switch and standby switch. Be sure to mount the standby switch
with its solder lugs directed toward the chassis top.
Standby Switch
Power Switch
Remove all 6 screws from the
terminals. You will not need
them for this project.
Take your time and line this up properly because the sticker
cannot be removed again without damaging it.

13
Step 4 – Mount the Bass, Treble, and Volume Pots
Drawing 7 shows where to mount the bass, treble, and volume pots. When they are mounted, turn their shafts all
the way counter-clockwise. (Once you have done this, you can mount the chicken head knobs while pointing to
“0” and tightening their set screws).
Bend back mounting tabs
250KA
Chassis Bottom
(2)
1MA
Chassis Bottom
(1) (3)
Set screw
Step 5 – Mount the Input Jack
Drawing 7 shows where to mount the input jack.
(1)
ccw
0 10
SECTION 3 – Mounting of Rear Components
Please refer to Drawing 8.
Step 1 – Mount the Rear-plate Label
Drawing 8 shows where to mount the rear-plate label. Make sure and line up each hole in the sticker with
each hole in the chassis rear.
Step 2 – Mount the Impedance Selector Switch and Output Jack
Drawing 8 shows where to mount the impedance switch and output jack. (Once you have done this, you can
mount the remaining chicken head knob to the switch).
There are 4 positions to the switch.
A) Mount the chicken head knob to the switch and gently click it over to the furthest counter-clockwise
position. (This position should be 4 ohms).
B) Re-adjust the knob so that it points at the “4” and tighten the set screw. Make sure that you can click over
to three more positions going in the clockwise direction.
(1)
Set screw
blk
red
It is good idea to use a
contact cleaner on each pot
before mounting.
Take your time and line this up properly because the sticker
cannot be removed again without damaging it.

Step 3 – Mount the Fuse Holder
Drawing 8 shows where to mount the Fuse holder. You can also insert the 2A slow blow fuse at this time.
F
U
S
E
SECTION 4 – Mounting Internal Terminal Strips and Passive Components
Please refer to Drawings 9 - 11.
Step 1 – Mount the Terminal Strips
Drawing 9 shows what you should see when you flip the chassis box over so that you are looking inside and
viewing from the rear side. The terminal strip mounting holes are labeled T1 – T9. (You will be mounting 9
terminal strips in this step)
Use #6 hardware and Drawing 10 to mount the 9 terminal strips in the same orientation as in the drawing.
(13)(13)(13)
(1)T1
T2, T6 (2)
T3, T4 (2)
T5, T8 (2)
T7 (1)
T9 (1)
Step 2 – Solder Components to Their Terminal Strip Locations
Please see page 7 “Soldering Tips” if you are new to making solder connections.
Drawing 11 shows each passive circuit component and its respective location on the terminal strip. Be sure to
follow the same orientation of polarity as shown in the drawing for diodes and polarized electrolytic
capacitors.
T1 Components
14
47Ω 1/2W 1
22kΩ 1/2W 1
1MΩ 1/2W 2
470Ω 1/2W 1
.1µF 630V 1
.001µF 630V 1
Resistors Capacitors
Note: Terminal strip terminals are
numbered from left to right with
mounting bracket directed towards
the viewer.

15
T2 Components
Resistors Capacitors
820Ω 1/2W 1
68kΩ 1/2W 1
22µF 50V 1
T3 Components
Resistors
20kΩ 1/2W 1
Capacitors
.1µF 630V 2
T4 Components
Resistors
100kΩ 1W 3
82kΩ 1W 1
T5 Components
Resistors
6.8kΩ 1/2W 1
68kΩ 1/2W 1
Capacitors
.022µF 630V 2
500pF 500V 1
T6 Components
Resistors
470Ω 1/2W 2 (6L6GC)
T7 Components
Resistors
1.5kΩ 1/2W 2
220kΩ 1/2W 2
T8 Components
Resistors
2.7kΩ 1/2W 1
2.4kΩ 1/2W 1
Capacitors
22µF 50V 1
1N4007 3
Diodes
1kΩ 5W 2 (EL34)
At this point, you need to decide between 6L6GC or EL34 power tubes and solder the appropriate resistors.
OR
(Copy the orientation of
polarity used in the drawing).
(Copy the orientation of polarity used in the drawing).
(Copy the orientation of polarity used in the drawing).

V3 Components
Resistors
1Ω 1/2W 1
One lead of this resistor must be connected to both V3 pins 8 and 1. The other lead must be connected to the locking lug nearby.
(*Measure this resistor with your DMM and take note that it most likely does not measure exactly 1.0 Ω)
Step 3 – Connect the Bias Check Resistors
Drawing 11 shows where to connect these resistors. (These resistors will help us when biasing the
power tubes at the end of the instructions).
V4 Components
Resistors
1Ω 1/2W 1
One lead of this resistor must be connected to both V4 pins 8 and 1. The other lead must be connected to the locking lug nearby.
(*Measure this resistor with your DMM and take note that it most likely does not measure exactly 1.0 Ω)
SECTION 5 – Solder the Filter Components
Please refer to Drawing 12.
16
Step 1 – Mount the Filter Components to Their Terminal Strips
Drawing 12 shows where to mount the filter caps from above and from the side.
(The labels: “HV, B, C, D, E, and V3 cathode” are used to identify the points where you will connect wires to
be fed through the grommet hole).
ground
Terminal 1
Terminal 2
Terminal 3
T10 Components
Resistors Capacitors
220kΩ 1W 1 80µF 450V 2
Negative side of bottom cap is connected to ground terminal
Positive side of top cap is connected to terminal 3
T11 Components
Resistors
220kΩ 1W 1 80µF 450V 2
Positive side of bottom cap is connected to terminal 1
Negative side of top cap is connected to terminal 1
Capacitors
Refers to the same
two caps

T12 Components
Resistors
Positive side of bottom cap is connected to terminal 1
Positive side of top cap is connected to terminal 3
Capacitors
22µF 500V 2
ground
Terminal 1
Terminal 2
Terminal 3
5kΩ 5W 1
1kΩ 1W 1
One end only of 1k connects to this terminal from T13
T13 Components
Resistors Capacitors
Positive side of bottom cap is connected to terminal 1
Positive side of top cap is connected to terminal 3
22µF 500V 2
1kΩ 1W 1
One end only of 1k connects to this terminal from T12
4.7kΩ 1W 1
T14 Components
Capacitors
Jumpers
22µF 500V 4
Negative sides of two 22µF@500V caps are connected to
terminal 1 (grounded)
Negative sides of the other two 22µF@500V caps are
connected to terminal 2 (grounded)
Add 2 jumpers wires (22 AWG) to T14 in
order to ground terminals 1 and 2.
J1 connects ground to terminal 1
Jumper Wires
J1 J2
J2 connects terminal 1 to terminal 2
Step 2 – Connect Wires to Filter Section
Drawing 12 shows where to connect these wires on each terminal strip. Use 22 AWG wire.
T10 Wires
Jumper
Add 1 jumper wire.
J3 connects T10 terminal 2 to T11
terminal 1
T11
T10
J3
HV
HV will connect to the standby switch.
(Make sure this wire has enough
length to get to the lamp holder on the
inside of the chassis). T10
grommet
HV
About 12.5"
in length
T12 Wires
B
B will connect to the power switch.
(Strip a little bit of the insulation on the
end that goes through the grommet to
help you identify it later).
(Make sure this wire has enough
length to get to the lamp holder on the
inside of the chassis).
C will connect to T6.
(Make sure this wire has enough
length to get to V4).
C
T12
12.5"
B
C
10"
17
(Drawing 14 can help you see where the other end of these wires will eventually be connected).
Stripped end

T13 Wires
D
D will connect to T4.
(Make sure this wire has enough
length to get to about an inch past T4).
E will connect to T4.
(Make sure this wire has enough
length to get to about an inch past T4).
E
T14 Wires
T13
4"
D
E
5"
V3 cathode will connect to V3.
(Make sure this wire has enough
length to get to about V4).
V3 cathode
T14
V3
cathode
13"
18
SECTION 6 – Connect the Front Mounted Components
Please refer to Drawings 13 - 17.
Step 1 – Connect the Potentiometers and Input Jack
Drawing 13 shows where to connect each pot.
A) Connect the cold lug of the Bass pot to T5 terminal 1.
cold
wiper
hot
B) Connect Bass wiper to the Treble cold (do not solder the treble cold side, yet).
C) Connect Treble cold to T5 terminal 4 (now solder the treble cold side).
D) Connect Treble wiper to Volume hot.
E) Connect Treble hot to T5 terminal 6.
F) Connect Volume cold to Input Jack ground pin
(do not solder the jack ground side, yet).
ground
switch
signal
G) Connect Volume wiper to V1 pin 7.
H) Mount but do not solder a 1MΩ, ½ W resistor from Input Jack switch pin to
signal pin.
I) Connect a jumper wire from Input Jack ground pin to switch pin and solder this
connection.
J) Connect Input Jack signal pin to T2 terminal 4. 14
T2
16
T5
Notice the following sub-step letters (A, B, C, etc.) are
shown on the Assembly drawings in parenthesis.

Step 2 – Connect the Power and Standby Switches
Drawing 13 shows some of these connections.
A) Connect the TR2 (red) to Pole B (do not solder this
connection, yet).
Standby Switch
Power Switch
Pole Throw
Pole
B
Throw
B
On
Throw
B
Off
Throw
A
On
Pole
A
Throw
A
Off
B) Connect the 1Ω, 5W resistor from Throw B Off to
the nearby locking lug.
C) Connect T8 terminal 5 to Pole.
D) Connect one end of the 360Ω, 10W resistor to Throw (do not solder this connection, yet).
(Leave enough room for this resistor to be able to connect
to the power switch without its leads accidentally
touching a neighboring connection point).
E) Twist and connect the two green TR1 wires to the lamp holder solder lugs (leave the top
holes open for a future connection).
(It does not matter which wire goes to which lug, but
make sure not to connect the wires to the same lug).
19
F) Twist and connect the TR1 grn/yel & red/yel wires to the nearby locking lug.
G) Twist and connect the two TR1 red wires to T8 terminals 4 & 6.
(It does not matter which wire goes to which terminal, but
make sure not to connect the wires to the same terminal).
H) Connect the TR1 violet wire to T8 terminal 1.
I) Twist and connect TR2 brown & blue wires to V3 pin 3 and V4 pin 3, respectively.
V3 pin 3 – brown wire
V4 pin 3 – blue wire
Step 3 – Connect the Filter Section Wires
Drawing 14 shows some of these connections.
A) Twist and connect wires “B” (w/ stripped end) and “HV” to their respective locations.
B connects to Pole B (do not solder, yet)
HV connects to Throw (now solder this
connection leaving enough room for the resistor
to swing over to the power switch).
B) Connect wire “C” to T6 terminal 3. 14
T6
16
T8
16
T8
Take your time when wiring these switches and be careful
not to unintentionally short any neighboring connections.
Make sure the Standby Switch connections do not touch
the chassis.
For example, the first part of Step 3 here is sub-step (A) and involves twisting wires “B” and “HV” together.
Be careful not to confuse the sub-step letters on Drawing 14 with the wire names.

C) Connect wire “V3 cathode” to V3 pin 1.
20
D) Connect wire “D” to T4 terminal 2.
E) Connect wire “E” to T4 terminal 5.
1 2 43 5 6
T4
Step 4 – Connect the Remaining Front Mount Components
Drawing 15 shows these connections.
A) Connect the other end of the 360Ω, 10W resistor to Pole B and now solder this connection.
Power Switch
Pole
B
Throw
B
On
Throw
B
Off
Throw
A
On
Pole
A
Throw
A
Off
B) Twist and connect two 20AWG green wires from the top lamp holder solder lugs to V4
pins 2 & 7 (do not solder the V4 ends, yet).
(It does not matter which wire goes to which lug, but
make sure not to connect the wires to the same lug).
D) Twist and connect two 20AWG green wires to the power switch “Throw A On” and “Pole
A” lugs and give them enough length to reach the rear panel of the chassis (about 10").
E) Connect the “Pole A” wire to T9 terminal 1 (do not solder this connection, yet).
C) Twist and connect TR1 brown & white wires to T9 terminal 3
(do not solder this connection, yet).
Note: Terminals are numbered from
left to right with mounting bracket
directed towards the viewer.
1 32
T9
Step 5 – Connect the Fuse Holder
Drawing 16 shows these connections.
A) Connect the “Throw A On” wire to the center lug of the Fuse Holder.
B) Twist and connect TR1 black & blue wires to the outer lug of the Fuse Holder
Center lug
Outer lug
SECTION 7 – Connect TR2 to the Impedance Selector Switch
Please refer to Drawing 17.
A) Connect jumper wire from C2 to C4
(do not solder the connection at C2, yet).
blk
red
1
1
1
2
2
2
3
3
3
4
4
4
A
B
C
Switch terminal name convention
(Because this resistor will get hot, make sure to prop it up so that its body does not lean against any wires).
blk
red
1
1
1
2
2
2
3
3
3
4
4
4
A
B
C
jumper
Take your time and be careful not to break any pins on the
switch or unintentionally short neighboring connections
that should not be connected.