Mod THUNDERDRIVE DELUXE LTD User manual

1Copyright © 2019 by modkitsdiy.com
Use these instructions to learn:
How to build an effects pedal for overdrive.
The Thunderdrive Deluxe LTD is an overdrive pedal kit that will provide a strong clean signal boost in the
early gain settings and smooth distortion at maximum gain settings. Adjusting output and distortion controls
provides a wide variety of tones in spite of its simple construction. It is capable of overdriving the preamp
section of your guitar amp or adding its own layer of distortion at lower volume. This version is equipped
with a three position diode selector switch.
The switch offers three different settings and tones. The top position is the classic silicon clipping diodes
used in the original Thunderdrive. The middle position gives you the lifted diode “turbo” sound from the
Deluxe model. The bottom position is a new setting limited to this version using germanium diodes for a
warm vintage distortion.
THE THUNDERDRIVE DELUXE LTD (K-956)
Unplug when not in use
to save battery life.
OUTPUT DISTORTION
DIODE SWITCH LED
Warning: This circuit was designed for use with a 9 VDC power supply only.
Signal Input
(From Guitar)
Signal Output
(To Amplifier)

TABLE OF CONTENTS
TOOL LIST …………………………………………………………………………...2
PARTS LIST DRAWINGS………………………………………………………….3, 4
SOLDERING TIPS …………………………………………………………………...5
STEP BY STEP ASSEMBLY INSTRUCTIONS …………………………………...6
Section 1 – Mount LED, ¼” Jacks and Terminal Strip Components ………..6
Section 2 – Mount Potentiometers, Footswitch and Toggle Switch ………..7
Section 3 – Mount and Connect Remaining Components ………..…………..7
Section 4 – Wire Remaining Connections ...……………………………...8
ASSEMBLY DRAWINGS (4 Drawings) …………………………………9, 10
These are the last 2 pages. They should be separated and used as a reference to help
assemble the kit correctly.
2
TOOL LIST
Wire Strippers
Needle Nose Pliers
Cutting Pliers
Desoldering Pump
Solder (60/40 rosin core)
Soldering Station
Phillips Head Screwdrivers
Slotted tip screwdrivers (3 mm tip)
Channellock Pliers (or similar type)
Ruler
Hobby Vise (or other means to secure box while working)

Enclosure
P-H1590BCE-BK (1)
Knob (Scalloped Edge)
P-K801P (2)
Battery Clip
S-H155 (1)
¼” Mono Jack (Output Jack)
W-SC-11-T (1)
¼” Stereo Jack (Input Jack)
W-SC-12B (1)
Stranded Wire (22 AWG) - Red
K-PUL1569 (3 FT)
PARTS LIST 1
3
RING LUG
SLEEVE LUG
TIP LUG
GROUND LUG
TIP LUG
250kΩ Potentiometer (Audio Taper)
R-VBM-250KA-SS (2)
Terminal Strip with 5 Terminals
P-0501H01 (1)
1 2 3
#4 Screw (3/8" long)
S-HS440-38 (1)
#4 Nut
S-HHN440 (1)
#4 Lock Washer
S-HLW4 (1)
3/8" Lock Washer
S-HLW38 (2)
3PDT Foot Switch
P-H501 (1)

PARTS LIST 2
4
yellow
violet
red
gold
4.7K
4.7kΩ Resistor ½ W
R-A4D7K (1)
red
black
green
gold
2M
R-A2M (1)
2MΩ Resistor ½ W
P-Q2N5088 (1)
NPN BJT (2N5088)
2N
5088
E B C
1N4148 HIGH SPEED SOLID STATE DIODE
P-Q971 (2)
gray
red
brown
gold
820
820Ω Resistor ½ W
R-A820 (1)
Light Emitting Diode
P-L400 (1)
+
-
DPDT Toggle Switch
P-H543 (1)
P-Q972 (2)
Germanium Diode (1N34A)
0.1µF Capacitor 50V
C-PFD1-50-R (2)
104J

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
5
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.

SECTION 1 – Mount LED, ¼” Jacks and Terminal Strip Components
Please refer to DRAWING 1 and DRAWING 2.
Orient the box with the ½” hole nearest you.
2) Mount input jack in the 3/8" hole on left side of box with hardware provided.
3) Mount output jack in the 3/8" hole on right side of box with hardware provided.
4) Mount the terminal strip to the 1/8" hole as shown in drawing 2.
GROUND LUG
TIP LUG
Output Jack
RING LUG
GROUND LUG
TIP LUG
Input Jack
6
Unless noted otherwise, connect and solder all of the following to their respective connection points
as stated. (Make sure none of the component leads are so close together that they could lead to an
unintended connection). Be careful not to overheat the solid state devices (diodes and transistor)
when soldering.
5) Strip and tin a 1 ½” piece of wire and connect terminal #1 to #3.
Washer goes under nut on outside of box. Make sure center “ground” lug of input
jack is facing up. Correct positioning of jack will make soldering connections much
easier. When positioned correctly, tighten nut.
Washer goes under nut on outside of box. Make sure the “tip” lug is on top
(towards the enclosure opening) before tightening nut.
We will refer to terminal numbers from “1” to “5” as illustrated.
You might want to connect to the lower terminal holes to leave room for other
components.
1 3
1) Mount the LED in the ¼” hole below the distortion pot’s
mounting hole. The lock washer goes over the threaded
portion prior to insertion through the top of the enclosure.
Align the LED leads so that the anode (long lead) is closer to
where the terminal strip will be as shown in Drawing 2.
The Anode (+) side of the LED is
indicated by a slightly longer lead
and/or a positive sign.
LED Physical
Representation
+
-
+-
LED Schematic
Symbol
anode cathode
6) Mount the 2N5088 transistor to terminals 3, 4 and 5.
Terminals #3: Emitter
Terminals #4: Base
Terminals #5: Collector
2N
5088
E B C
Do not solder.
7) Mount the 4.7K resistor to terminals 2 and 5. Do not solder.
8) Mount the 2M resistor to terminals 4 and 5. Do not solder.
yellow
violet
red
gold
4.7K
red
black
green
gold
2M
The orientation of the jacks is shown in the drawings is for ease of soldering and clarity in
the diagram. The jacks may need to be rotated so the tip does not touch the chassis when a
cable is plugged in.

7
SECTION 2 – Mount Potentiometers, Footswitch and Toggle Switch
1) Mount the two 250K potentiometers in the 3/8" holes at the top of the enclosure using the
hardware provided.
Remove nut and flat washer from potentiometers and
place large lock washers (S-HLW38) over shaft of each
pot before inserting them through their mounting holes.
Fasten nut over flat washer and tighten. 1 2 3
1 2 3
Before mounting, gently
bend the pot lugs back so
they are pointing straight
up when mounted.
2) Mount the 3PDT footswitch in the ½” hole with its solder
lugs oriented as in the drawing.
(The top hex nut should be fastened on the outside of the box. The plastic
washer is optional.)
Please refer to DRAWING 3 & DRAWING 4.
3) Mount the DPDT toggle switch in the ¼” hole below the output pot. The lock washer goes over the
shaft before inserting through the chassis hole. Align the switch as shown in the drawing and tighten
the nut.
Incorrect OrientationCorrect Orientation
4) Connect the 820 Ω resistor from terminal #2 to the anode (+) lead of the LED.
Clip the anode lead of the LED and resistor to a reasonable length and connect them by bending and crimping the leads
around each other. Solder them once they are tightly connected to each other.
5) Take the two 1N4148 diodes and place their bodies side by side with the reverse polarity of one
another (see below) and twist their leads together as shown.
Connect one end of these two 1N4148 diodes to terminal #1 of the terminal strip and the other end to
the bottom left lug of the toggle switch. Make sure the leads of these diodes will not accidentally touch
any of the other lugs on the toggle switch.
cathodeanode
cathode side is
marked with a
black band
“Reverse polarity of one another”
means to connect the cathode of
each diode to the anode of the
other diode.
6) Take the two germanium diodes and place their bodies side by side with the reverse polarity of one
another (see below) and twist their leads together as shown.
Connect one end of these two germanium diodes to terminal #1 of the
terminal strip and the other end to the top left lug of the toggle switch.
Make sure the leads of these diodes will not accidentally touch any of
the other lugs on the toggle switch.
cathodeanode
cathode side is
marked with two
black bands
“Reverse polarity of one another”
means to connect the cathode of
each diode to the anode of the
other diode.
Top Left
Middle Left
Bottom Left

3) Locate the battery clip. Cut 1 ½” length off the ends of each
lead and discard (or save for other projects). Connect the black
lead to the “ring” lug of the input jack. Connect the red lead to
terminal #2 of the terminal strip. Solder these connections now.
SECTION 4 – Wire Remaining Connections
1) Strip and tin a 1 ½” piece of wire and connect footswitch lugs “3” and “9”.
2) Strip and tin a 1" piece of wire and connect the input jack “tip” lug to the footswitch lug “2”.
3) Strip and tin a 3 ½” piece of wire and connect footswitch lug “1” to distortion pot lug “1”.
4) Strip and tin a 1 ¾” piece of wire and connect the output jack “ground” lug to
output pot lug “3”.
GROUND LUG
TIP LUG
5) Strip and tin a 1 ¼” piece of wire and connect the output jack “tip” lug to
footswitch lug “8”.
6) Strip and tin a 2 ½” piece of wire and connect the output pot lug “2” to footswitch lug “7”.
Finish it off by double-checking all of your connections, connect and insert a 9V battery, screw the lid on and
fasten the knobs to both pot shafts.
RING LUG
SLEEVE LUG
TIP LUG
8
7) Strip and tin a 2 ½” piece of wire and connect the cathode lead of the LED to footswitch lug “4”.
Solder both of these connections now.
8) Strip and tin a 1 ½” piece of wire and connect the footswitch lug “5” to the ground lug of the input
jack. Solder these connections now.
SECTION 3 – Mount and Connect Remaining Components
1) Connect one of the 0.1µF capacitors with one lead at terminal #5 of the terminal strip and the
other lead to output pot lug “1”.
2) Connect the other 0.1µF capacitor to terminal #4 and to both lugs “2” and “3” of the distortion pot.
Solder all connections at terminals #3, #4 and distortion pot lugs “2” and “3” now.
Please refer to DRAWING 4.
9) Strip and tin a 1” piece of wire and connect the DPDT switch middle left lug to the output pot’s lug
“1”. Solder these connections now.

-+
1/2"
1/8"
3/8"3/8"
3/8"
1/4" 1/4"
3/8"
DRAWING 1
TOP
LEFT SIDE
RIGHT SIDE
DRAWING 2
INPUT JACK OUTPUT JACK
1
5
2N
5088
4.7K
2M
B
E
C
DISTORTION
POT HOLE
9
+

-+
1 2 3 1 2 3
DRAWING 3
INPUT JACK OUTPUT JACK
1
5
2N
5088
4.7K
2M
B
E
C
OUTPUT
POT
DISTORTION
POT
-+
1 2 3 1 2 3
DRAWING 4
INPUT JACK OUTPUT JACK
1
5
2N
5088
4.7K
2M
B
E
C
OUTPUT
POT
DISTORTION
POT
104J
104J
1
2
3
4
5
6
7
8
9
820
BLK
RED
10
+
-
P-H501

+
-
9 VDC
Battery
Output
Input
Foot
Switch
(A)
Foot
Switch
(C)
2
1
3
7
8
9
4.7K
2N5088
Q1
C
B
E
.1µ
250KA
2M
1N4148 1N4148
250KA
.1µ
OUTPUT
DISTORTION
+-
820
Foot
Switch
(B)
5
4
6
3PDT Foot Switch
1
2
3
4
5
6
7
8
9
Switching function of the 3PDT switch. The solid line
illustrates an internal connection between terminals.
1
2
3
4
5
6
7
8
9
1N34A 1N34A
3 Position
On-Off-On
Copyright © 2019 by modkitsdiy.com
“Thunderdrive Deluxe LTD”
Schematic
Base
Emitter
Collector
2N5088
NPN BJT
BCE