Random*Source Serge TWS+ User manual

RANDOM*SOURCE
RANDOMSOURCE.NET 1
Serge TWS+
SERGE
Triple+ Waveshaper
(TWS+) for Eurorack
The TRIPLE WAVESHAPER (TWS) is a non-
linear modier which can transform a sawtooth
wave into a sine wave. This classic module
incorporates three independent waveshapers
for modifying synthesizer waveforms or for
processing signals from preamplied instruments.
Although originally designed as a waveshaper
for early Serge oscillators, this module has been
found to be a excellent modier of electronic and
acoustic sounds, and is highly recommended for
subtle timbral modications beyond the range of
simple oscillator/lter patches.
The R*S version extends the classic TWS
concept:
• +1: An additional (4th) waveshaper has been added (right after the rst / bottom waveshaper) that
can be dialed in smoothly using the +1 knob. Turned down (CCW) the bottom section acts as in the
original (as if that additional waveshaper would not exist). Turned up (CW) the bottom section is actually 2
waveshapers in series.
• Switches to link the 3 sections - bottom to top. Using these switches all sections can be set to act in
series, starting at the bottom and ending at the top, providing the combined effect of 3 to 4 waveshapers
(or anything in between) using the +1 knob.
• Linking only the middle and top section and turning the +1 knob up (to have 2 sections in the bottom)
allows you to use the module for isntance as two independent 2-stage waveshapers (using bottom in
and out for one and middle in and top out for the other) - e.g. for stereo processing.
The Random*Source version is a licensed and authorized adaption of the original Serge design.

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Serge TWS+
The Random*Source TWS kit consists of a front panel and a pcb with all SMT components already installed,
that als serves as an interface to the front panel.
TWS+ pcb (v 1.00):
- blue indicates (required) through-hole parts to be inserted / pins to be soldered -
Please note:
• The front panel is screen printed for nice saturated colors. That means the paint is on top of the
anodised aluminum. Therefore it is important to avoid mechanical or chemical inuences (scratches,
acid, solvents) than other printing techniques. Do not use strong cleaning uids or abrasive cleaning tools.
• Outputs are by default unipolar (DC, white jack) - i.e. ranging (about) 0 to 5V. As an option, each out-
put can be modied so you can jumper between DC and AC (installing jumpers requires removal of the
resistors marked pink above). However, that is not required (or particularly recommended). So you can
simply ignore the jumper sections and the large 47uF capacitors.
• No trimmers / trimming required - the pcbs is already preset for standard voltage levels. As an option,
you can install trimmers, however, you have to remove a number of resistors for that.
• Board is designed to be powered by a +/-12V stabilized PSU only. (+/-15V is untested).

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Serge TWS+
Bill of Materials
Trimmers
(4) 20k GAIN 1, 1+, 2, 3 OPTIONAL! Trimpot (Bourns 3362P or anything that matches the foot-
print). Not required / recommended - see “Options” below!
Capacitors
4 470n 5 mm lead spacing Film caps, e.g. WIMA MKS 2-5
Misc
1 Euro Power
header
MTA-100 power connector, Reichelt: WSL 10G
12 Thonkiconn
Jacks
3.5mm Jack Sockets (PJ301M-12) from Thonk
2 Switches SPDT ON - ON or ON - OFF (2 positions) Sub-Miniature Switch, e.g. Mountain Switch
(Mouser: 108-0042-EVX)
7 Potentionmeter
50k or 100k
linear (B50K or B100K) Alpha 9mm vertical pcb mount
available from Thonk, Tayda, Mouser ...
1 Potentionmeter
10k
linear (B10K) Alpha 9mm vertical pcb mount
available from Thonk, Tayda, Mouser ...
Building
This is simply a suggestion - you might nd a different workow more practical:
1. Read section “Options” below rst - these are not required or ever recommended, however, should you desire to
implement them it makes sense to think about it before you start building.
2. Solder the lm caps and power connector onto the pcb. The picture above shows in blue all spots to be installed /
soldered (for a standard build without any options).
3. You can ignore the jumpers and the electrolytic caps.
4. Mount the Thonkiconn jacks, the pots and the switches onto the pcb. Pots should sit on the side facing the front
panel (as marked on the board). Don‘t solder them in yet.
5. Carefully mount the pcb (with the pots etc. inserted) onto the front panel. You may then have to wiggle each pot a
bit to get the pots through. Make sure the threads of the pots go through completely and the pots sit right at the
front panel. Screw the jacks and pots to the panel.
6. Once everything is nicely in place, solder the pots, jacks und switches onto the pcb (while the front panel is
attached). You should solder the blues pins / spots shown in the picture above. In some areas there is not a lot of
space towards the surrounding SMT components, so be careful not to burn or desolder anything else.
7. Connect a power cord supplying +12V, GND, GND, -12V to the power-header on the main board and double check
the direction of the power header before you turn power on. You should be ready to go :-)

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Serge TWS+
Options
A. Selectable output DC / AC via jumper
There are 3 jumpers provided for on the pcb - each to allow to set the output of that section to unipolar (DC,
about 0 to 5V) or to AC (centered around 0V). By default, the board is already jumpered to DC - consistent with
the white jacks on the front panel. So there is no need to do anything to use the module.
However, if you want to be able to jumper each or some of the optputs to AC, you have to (for each output):
1. Remove the 0R resistor (link) next to the jumper pads
2. Install a big 47uF electrolytic cap - I use Nichicon BP (bi-polar / non-polar) audio grade, BP should not be needed,
however I have not tried any others.
3. Install 3 pin jumpers as indicated on the pcb and set the jumper to either AC or DC. (Output will not work if you do
not set the jumper where you have removed the 0R resistor).
If you decide to implement the jumpers, it is easiest to do this as the rst step - in particular before you attach
the front panel and solder the pots etc.
B. Gain trimmers
The pcb is pre-congured so you don’t need any trimmers or trimming. Using trimmers could allow you to adjust
the output level of each section precisely. However, due to the nature of the module and DC offsets involved in
teh folding action, I see no reason to try that - the default should work nicely. Just be aware that you cannot
simply install the trimmers, you would also have to remove 2 resistors rst.
So the simple recommendation is: Do not install the trimmers.
Calibration
No calibration needed :-)
Power consumption etc.
Power consumption: <=20mA @ +12V and <=10mA @ -12V
Module width: 18HP, depth: < 30 mm
(Last changes: 11. July 2019, 9:57 PM)
SERGE Modular by Random*Source. Module and circuit under license from Serge Tcherepnin. All rights reserved.