Lithium Grim Magnum Instruction Manual

Magnum
Building instructions
V1.0

Magnum v1.0
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
2
Table of contents
Components ............................................................................................................................................ 3
PCB layout............................................................................................................................................... 3
Building sequence ................................................................................................................................... 4
Modifications........................................................................................................................................... 5
Diodes and Op amp............................................................................................................................. 5
Clipping Diode Configurations............................................................................................................. 5
Off board wiring ...................................................................................................................................... 6
Troubleshooting ...................................................................................................................................... 7
Schematic ................................................................................................................................................ 8
Read this entire manual thoroughly before you start building the effect! Especially the modification
part. Decide before building the effect which mods you want to try so that you do not need to
desolder parts later.
Last update: 02-02-2020

Magnum v1.0
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
3
Components
Name
Value
Comment
Name
Value
Comment
C1
220p
MLCC/Ceramic
D8
1N4001
C2
150n
SMF/MKT/Wima
D9
1N4001
C3(a)
22p
MLCC/Silver Mica
D10
1N5817
C4
100n
SMF/MKT/Wima
D11
1N5817
C5
470n
SMF/MKT/Wima
DIP1
DIP2
C6
4u7
Electrolytic 25V+
IC1
JRC4558
C7
47n
SMF/MKT/Wima
IC2
LT1054
C8
2u2
Electrolytic 25V+
P1
A250k
Gain
C9
10u
Electrolytic 25V+
P2
A25k
Bass
C10
47u
Electrolytic 25V+
P3
B10k
Treble
C11
100n
SMF/MKT/Wima
P4
B100k
Volume
C12
47u
Electrolytic 25V+
R1
1M
1% metalfilm
D1
1N34A
MLCC/Ceramic
R2
470k
1% metalfilm
D2
1N914
Germanium Diode
R3
4k7
1% metalfilm
D3
1N34A
Germanium Diode
R4
820R
1% metalfilm
D4
1N34A
Germanium Diode
R5
10R
1% metalfilm
D5
1N4001
Germanium Diode
R6
47k
1% metalfilm
D6
1N4148
R7
47k
1% metalfilm
D7
1N4148
SW1
DP3T
Caliber (diodes)
SW2
SPDT
Voltage
PCB layout
A=Log, B=Lin, C=Rev. Log

Magnum v1.0
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
4
Building sequence
Soldering this board can be very complicated for some people since the solder pads are very close
together. Use a magnifying glass to make the job easier.
First decide which charge pump you want to use. IC2 can fit a LT1054 or even the cheaper ICL7660S.
When using the 7660S, you must place a jumper in J1! Do not blow on your solder in an attempt to
cool it down. That will possibly result in a bad join that might corrode!
If you want to experiment with other diodes then you could socket them instead of soldering them to
the board. You’ll need a 20 SIL, break off the sockets and solder them to the board. Note: Glass
diodes are fragile. Do not expose them to heat for too long or they’ll break!
Start by soldering the jumper (if needed), resistors and then the diodes (if not socketed). Solder the
IC socket next and then the small SMF/MKT capacitators, the DIP switch, the electrolytes and finish
with the C3 silver mica. If you want to use a regular 22pF MLCC for C3, you can use the C3a pads.
Do not yet place the IC (and diodes if socketed). Wait until after you soldered the potentiometers
and switches.
Besides the components mentioned in the table on the page 4, you will need:
•2 input jacks. 2 mono jacks if you are not going to use a battery but only the 9V adapter. 1
mono (for output) and 1 stereo jack (for input) if you will be using both a 9V battery and the
9V adapter.
•3PDT footswitch (9 pins)
•2,1mm DC jack (isolated).
•9v battery clip (optional).
•22 gage stranded hook-up wire.
•LED and LED flange.
•Hammond 125Bcase (or similar) in your favorite color.If you need more space, use a
Hammond 1590BB.

Magnum v1.0
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
5
Modifications
Diodes and Op amp
You can use other diodes than the mentioned combinations. Try LED’s, MA858/859 (very nice!!),
D9E, etc. D1-D4 best fit the bigger glass germanium diodes. D5-D8 best fit the smaller silicon diodes.
IC1 can be any dual op amp of your liking. Try the JRC4558, JRC4559, AD712, MC1458, TL072,
OPA2134, OP275, etc, etc.
Clipping Diode Configurations
There are really a lot of ways to configure the diodes in the soft clipping section of this effect. There
are 2 diode sections that you can load with whatever 4 diode combination you like. The Dip switch is
added so that you can switch between symmetrical and asymmetrical clipping. Dipswitch 1 bypasses
D8 and dipswitch 2 bypasses D1.
Feel free to experiment with different diodes and configurations. SW1 is a DP3T (on-off-on) switch
that enables you to switch between the 2 sections and in the middle position is takes out any diode
section to let you hear the op amp clipping only.

Magnum v1.0
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
6
Off board wiring
The biggest challenge of this build is to get all the offboard wiring correct and fit it in a box. Take your
time measuring and testing before you start fitting everything in the box.
P1-P4 are PCB mounted potentiometers (Alpha). The rectangle pad marks pin 1 of a potentiometer.
The images below show how you can recognize which pin is which on a potentiometer. You can
break off the pin I marked with the yellow circle with a small pair of pliers.
SW1 is a regular DP3T (on-off-on) switch with solderlugs and SW2is a PCB
mount version SPDT switch.
Place the potentiometers and switches in the predrilled enclosure and then
insert the PCB. Once the PCB fits nicely and is not touching the enclosure, solder
the potentiometers and switches to the PCB.
Now you will need to wire the footswitch, LED and DC jack:
The LED requires a resistor (R led in the diagram) depending on the type of LED you are using. An
ultra-bright red, green or blue LED requires a 4k7 resistor, diffuse green requires 680R. If you want to
be more exact then go here: http://www.muzique.com/schem/led.htm
S
Tip
Sleeve
Sleeve
Output Jack
Input Jack
Cathode (short leg)
Anode (long leg)
Footswitch
Ring
R led
Tip

Magnum v1.0
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
7
Troubleshooting
All PCB’s have been 100% factory e-tested and out of every batch I receive I build an effect to double
check, so there should not be a connection problem on the PCB itself.
The board is not working (at all), what now?
•Check if your 9V is plugged in correctly (and/or soldered correctly on the board).
•Check that you oriented the capacitors, IC’s ,transistors and diodes the right way. SMF, MKT
and ceramic capacitors as well as resistors do not need to be oriented.
•Check if you used the correct values of the components. For resistors you can look here:
http://www.diyaudioandvideo.com/Electronics/Color/
•Double and triple check your soldering! A loose or cold solder can be really bad for your
board.
•Replace the IC, it might be defective. Before doing that first unplug the 9V and wait for 5
seconds.
•Check that you have good/high grade components. A lot of Chinese sourced parts are fakes
(especially high end opamps, vintage diodes and transistors) so be careful that you source
your parts from reliable suppliers.

Magnum v1.0
Manufacturer and product names are mentioned solely for circuit identification, and where applicable their trademarks are the
property of their respective owners who are in no way associated or affiliated with the author. No cooperation or endorsement
is implied.
8
Schematic