Lithium Grim The Senator Instruction Manual

The Senator
Building instructions
v1.0

The Senator v1.0
Manufacturers 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
PCB layout ............................................................................................................................................... 3
Components ............................................................................................................................................ 4
Power section.......................................................................................................................................... 5
Hardwire voltages ............................................................................................................................... 5
9V only................................................................................................................................................. 5
Build sequence ........................................................................................................................................ 5
Enclosure (drilling)............................................................................................................................... 6
Off board wiring ...................................................................................................................................... 7
Potentiometers non PCB mounted ..................................................................................................... 7
Potentiometers PCB mounted ............................................................................................................ 7
Switches............................................................................................................................................... 8
Modifications......................................................................................................................................... 10
Transistors ......................................................................................................................................... 10
Op amp.............................................................................................................................................. 10
Clipping section ................................................................................................................................. 10
Pots.................................................................................................................................................... 11
Troubleshooting .................................................................................................................................... 11
Schematic .............................................................................................................................................. 12
Read this entire manual thoroughly before you start building the effect! There are some available
options and you should choose which one you want to incorporate before starting your build.
Last update: 27-03-2018

The Senator v1.0
Manufacturers 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
PCB layout
Dimensions: 84 mm x 49,6 mm
3.31 inch x 1.95 inch

The Senator v1.0
Manufacturers 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
Components
Name
Value
Comment
Name
Value
Comment
C1
10n
SMF/MKT/Wima
IC1
TL072
see modifications
C2
100n
SMF/MKT/Wima
IC2
LT1054
C3
120p
MLCC
P1
B100k
Gain
C4
220n
SMF/MKT/Wima
P2
A10k
Treble
C5
100n
SMF/MKT/Wima
P3
A10k
Mid
C6
220p
MLCC
P4
A10k
Bass
C7
220n
SMF/MKT/Wima
P5
B100k
Level
C8
4n7
SMF/MKT/Wima
P6
C25k
Boost
C9
10n
SMF/MKT/Wima
Q1
BS170p
C10
220n
SMF/MKT/Wima
Q2
2N5457
C11
100n
SMF/MKT/Wima
R1
2M2
1% metalfilm
C12
68n
SMF/MKT/Wima
R2
1M
1% metalfilm
C13
47p
MLCC
R3
2k2
1% metalfilm
C14
470p
MLCC
R4
10k
1% metalfilm
C15
220u
Electrolytic 25V+
R5
680k
1% metalfilm
C16
100n
SMF/MKT/Wima
R6
1k
1% metalfilm
C17
10u
Electrolytic 25V+
R7
1k5
1% metalfilm
C18
47u
Electrolytic 25V+
R8
100R
1% metalfilm
C19
100u
Electrolytic 25V+
R9
680R
1% metalfilm
C20
100n
SMF/MKT/Wima
R10
680R
1% metalfilm
C21
100n
SMF/MKT/Wima
R11
1k
1% metalfilm
C22
10u
Electrolytic 25V+
R12
47k
1% metalfilm
C23
4u7
Electrolytic 25V+
R13
47k
1% metalfilm
C24
100n
SMF/MKT/Wima
R14
2M2
1% metalfilm
C25
330p
(optional) MLCC
R15
10M
1% metalfilm
D1
1N4148
R16
10M
1% metalfilm
D2
1N4148
R17
100k
1% metalfilm
D3
1N4148
R18
5k1
1% metalfilm
D4
LED RGB
common anode
R19
1M
1% metalfilm
D5
LED RGB
common cathode
R20
1M
1% metalfilm
D6
Zener
12V
R21
5k1
1% metalfilm
D7
1N5817
SW1
see modifications
Variac1
D8
1N5817
SW2
SP3T
Caps
D9
Zener
9,1V or 10V
SW3
see modifications
Push
DIP1
Clipping
DIP4
SW4
see modifications
Variac2
VR1
B100k
Pre-Gain trimpot
All parts need to be 25V+ rated
A=Log, B=Lin, C=Rev. Log

The Senator v1.0
Manufacturers 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
Power section
IC2 can be either a LT1054 or a (cheaper) ICL7660S. If you want to use the 7660S then you’ll need to
connect both pads of J1
I do not advise to use a battery in this build as the charge pumps will do strange things when the
battery is depleted. This is why it is also left out in the off board wiring section.
If you do not want to make the voltages of the effects switchable, then you have several options.
Hardwire voltages
SW1 determines the voltage for the distortion side (guvnor) and SW4 determines the voltage of the
boost side (SHO). If you connect pads 1 to pad 2 on either switch, you will feed that side with 18V.
Connect pad 2 to 3 and you will feed it 9V. Pads are marked like this:
9V only
For this you can leave out C17, C18, C20, D7, D8, IC1 and hardwire SW4 pads 2-3 and SW4 pads 2-3.
Build sequence
Before starting with this section, make sure you have read the modifications section first!
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.
The trick to soldering a PCB is to work from small to big components. My building sequence
suggestions in this section are based on the parts I used myself. Sometimes some components are
smaller (or bigger) so always use your own common sense and change the order accordingly. Usually
capacitors can differ a lot in size depending on their rating and value.
Note: Do not blow on your solder in an attempt to cool it down. That can result in a bad join that
might corrode! Also take extra care not to short components.
Start by soldering the diodes D1-D3 (if applicable), resistors and jumpers (if applicable). If needed you
can create a jumper using a spare piece of lead from a resistor or diode. Next come the diodes (not
the LEDs).
If you want to experiment with other transistors then you could socket them instead of soldering
them to the board. You’ll need a some 20 SIL sockets, break off the sockets and solder them to the
board. Now is the time to solder these sockets on the PCB as well as the socket for the IC. Place the
transistors and IC once you are finished with all soldering and off board wiring!
Now continue by soldering the MLCC, SMF/MKT/Wima capacitors then solder the internal trim pot
(VR). Now finish with soldering the transistors (if not socketed), LEDs and the Electrolytics.
3 2 1

The Senator v1.0
Manufacturers 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
Enclosure (drilling)
I suggest you now drill the holes in your enclosure so you can use it during the off board wiring.
Here is a suggestion for drilling:
Pots need a 7 mm hole and switches (Caps, Push, Variac) need 6 mm holes. Diameters might differ
with different brands. The optional LED hole is 5mm. Read the modifications section to learn more
about the LEDs
You are free to choose where to drill the holes for the input/output and DC jacks and the
footswitches as it is very taste dependent.
Note: Really take some time to determine where and how to place the pots, switches, jacks and PCB
in the enclosure before you start drilling. Measure twice, drill once.
Besides the components mentioned in the components table, you will need:
2 mono input jacks.
2,1mm DC jack (isolated).
22 gage stranded hook-up wire.
2 x LED holders. This enables you to mount the LEDs in the enclosure.
2 x Footswitch 3PDT (9 pins)
2 x LED (3mm or 5mm depending on your taste). These are the status LEDs
Hammond 1590BB case (or similar) in your favorite color. This case will fit very tight and
leaves little room for error. If you need more room you could consider using a Hammond
1590XX.
27,9mm
24,9mm
25,4mm
27,9mm
Treble Mid Bass
Boost
Level
Gain
Push
Variac1 Variac2
13,95mm 13,95mm 13,95mm 13,95mm
RGB LED
(optional)

The Senator v1.0
Manufacturers 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
Off board wiring
You can either mount the potentiometers directly to the PCB with special potentiometers or use the
more traditional solderlug potentiometers.
Potentiometers non PCB mounted
In the pictures below you see the correct pin numbering of the pots (Alpha 16mm style).
Solder the wires accordingly and it is always a good idea to twist the wires together to create some
extra shielding against external noise. The rectangle pad marks the pad for pin 1.
You can break off the pin I marked with the yellow circle with a small pair of pliers.
The wiring for the switches is the same, marking position 1 with a rectangle pad.
Potentiometers PCB mounted
Start by mounting the potentiometers to the PCB (bottom side), but do not solder them yet! Make
sure you removed the pin with a small pair of pliers and that you screwed off the nuts. Also check if
the component leads on the bottom side are cut as short as possible so they will not stick out too
much. While holding the PCB move it in the enclosure like this:
Now rotate the PCB and attach all nuts to the potentiometers and tighten them. If all fits well, solder
the pots to the PCB, else adjust where needed. Make sure the bottom of the pots do not contact the
PCB in any way as this might result in short circuit or other strange behavior! You can use the
standard plastic caps that you can buy for the alpha pots, or tape the PCB under the pots of with
some duct tape.
Gain Treble Mid
Bass Level Boost
3 2 1 3 2 1 3 2 1
3 2 1 3 2 1 3 2 1

The Senator v1.0
Manufacturers 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
Switches
The PCB was designed so that 3 single pole switches will fit easily in the enclosure. There is a special
gap made in the PCB which will fit almost all types of miniature single pole switches. There are a lot
of configurations possible, and you are free to experiment. By default you can use this configuration:
In this configuration, SW2 (caps) is not installed. You could use a small internal SP3DT switch (ON-
OFF-ON), make a 3pin header with a shunt like in the picture or hardwire it. There are other
configurations possible like this one:
Note that there is little room between the potentiometers and when trying to fit a DP3T between
them you cannot use the optional plastic cases on the potentiometers. Fit before you decide!
There are different types of DP3T On-Z-On switches. Check which contacts connect in the middle
position and change the wiring if it is not to your liking!
Switch in middle position
Variac 1 SPDT
(On-On)
Variac 2 SPDT
(On-On)
Push SPDT
(On-On)
<- on off ->
Variac DP3T
(On-Z-On)
Caps SP3T
(On-Off-On)
Push SPDT
(On-On)
<- on off ->
1 2 3
6 5 4

The Senator v1.0
Manufacturers 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.
9
Ring
Sleeve
Tip
Cathode (short leg)
Input
R led1
R led2
Anode (long leg)
Cathode (short leg)
Anode (long leg)
Tip
Sleeve
Output
Note that R led1 and R led2 are 4k7 resistors. You can change these values depending on the type of
LED you use but 4k7 is safe enough for almost all LEDs @9V.

The Senator v1.0
Manufacturers 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.
10
Modifications
Transistors
Q1 is based on the BS170P as used in a lot of Zvex™pedals. You could use the regular BS170 instead
of BS170P but note that the pinout is different (reversed)!
Op amp
You could use a OPA2134 instead of the TL072. Actually you can use almost any dual opamp as long
as the pinout is similar to the TL072 and can handle up to +18V. Some suggestions NE5532, TL082,
JRC4558P or JRC4580D. Feel free to experiment!
Clipping section
Diode section has a lot of options. Let’s walk through the standard layout.
The clipping section consists of D1-D5 and can be switched with the DIP switch DIP1. Switch 1
switches the red LEDs of D4 and D5, Switch 2 switches the green LEDs of D4 and D5 and Switch 3
switches the blue LEDs of D4 and D5. All options of switch 1-3 are symmetrical clipping. Switch 4 is a
special one as it switches D1,D2 and D3 and uses a-symmetrical clipping.
By default D1-D3 are 1N4148. You could consider changing D2 to a red diffuse LED, which will make it
a bit smoother. You might have to bend it a bit so it will not stick out to much.
D4 and D5 are RGB LEDs and you need to take some time and determine how you want to place
them on the PCB. The LEDs light up really nice and you might consider making them visible from the
outside of the enclosure. To do this, I would advise you to insert D5 from the bottom side of the PCB
and D4 from the top side. Make sure you do not solder DIP1 and D5 until you have drilled the
enclosure and soldered the pots because the hole is off by 0,4mm. First solder D4 on the component
side as close as possible to the PCB with the rest of the components and when ready insert D5 in the
PCB (do not solder!!) and make it fit both the PCB and enclosure. When it fits, solder it to the PCB
while it is in the enclosure. Yes, that can be difficult for some and make sure the soldering is clean as
the pads are close together. Finish by soldering DIP1.
If you do not want the RGB to be visible then still solder D4 on the topside and D5 to the bottom side
but as close as possible to the PCB. When ready, bend the LEDs (especially D5) so it will not stick out
to much and touch the enclosure.
This is the pinout of RGB Leds: And this is the way it fits on the PCB:
source: arduino.cc
R (C) G B
C is the common, either + or –
The extra center hole is a common
which goes to ground

The Senator v1.0
Manufacturers 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.
11
Pots
C25k PCB mounted pots are very hard to find. You could use a regular C25k alpha pot and mount it to
the PCB with some spare leads like this:
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). Pay special
attention to the polarity.
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. A likely sign of
incorrect capacitors and/or orientation is when an effect is sputtering, rumbling or
“motorboating”.
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 and/or transistors, one 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, audio capacitors, vintage diodes and transistors) so be careful
that you source your parts from reliable suppliers.

The Senator v1.0
Manufacturers 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.
12
Schematic