The classic Serge Triple Waveshaper (TWS+) by Random Source is a very easy synth DIY build. With the addition of just a couple of jack, pots, capacitors, and a header I had it up and running in no time. A gorgeous sound sculpting addition to my Eurorack modular synth.
In the early seventies, composer and electronic designer Serge Tcherepnin had a vision to create the peoples synthesizer. It resulted in the creation of unique sounding Serge Modular Music Systems.
Random Source licensed the classic designs from him and ported some of them to the Eurorack format. One of those magnificent modules is the Triple Waveshaper (TWS+). The plus stands for an added Waveshaper in the bottom section of the module.
Take a listen and find out what this versatile module can do on simple waveforms.
This module is a unique modifier of electronic and acoustic sounds and highly recommended for subtle timbral modifications beyond the range of simple oscillator/filter patches.
So let’s get started building one for our Eurorack system.
Where to get the kit and parts?
You can buy the Serge Triple Waveshaper Kit for Eurorack from Random Source in Germany. This kit contains the panel and PCB with all the surface mount component preinstalled.
There’s a bill of materials (BOM) on the website which lists all the components you still need to acquire before building the kit. So before you get started, you need to buy extra parts:
- 4x 470nF Red Wima film capacitors MKS 2 5mm spacing at Mouser
- 1x 2×5 pins header 2.54mm spacing for the power connection at Mouser
- 2x Mountain Switch SPDT ON-ON from Mouser
- 8x Knob Black – 6.35mm Round Shaft with white stripe from Thonk
- 12x Thonkiconn Jacks PJ301M-12 (plus hex nuts and washers!) from Thonk
- 7x 100k Alpha 9mm linear potentiometer vertical from Thonk
- 1x 10k Alpha 9mm linear potentiometer vertical from Thonk
- 1x Eurorack Power Cable 10-16 Pins from Thonk
Note: If you don’t like to go out and buy these parts yourself, you can also buy the full TWS+ kit from Thonk which contains all the parts listed above.
Building the Triple Waveshaper step by step
So with all parts collected and the PCB on the bench we can start by heating up our soldering iron. I use an Ersa i-CON PICO soldering station with a small shizzle tip at 360 degrees Celsius / 680 degrees Fahrenheit. This entry level station has a small footprint on my desk and heats up pretty fast.
Since all resistors are SMT we can start by soldering the four Wima 470nF film capacitors in place. The 470n values are printed on the PCB.
Snip off the excess leads from the soldered caps and continue with the headers for the Eurorack standard 10 pin power cable. You can use a shrouded header case, but I went for two rows of five pins. I didn’t have a 2×5 pins header so I used a 14 pins header. It’s easy to snip the 14 pins header into two rows of five.
Attach a power connector to keep the two headers in place while soldering. I fixed the cable with some painters tape first. After soldering remove the power cable again.
So let’s continue on the other side of the board with the 10k linear potentiometer. There’s a clear 10k value marking for this pot on the PCB. Don’t solder yet.
Install the 100k linear pots on the spots marked with 100k on the PCB. Still, don’t touch anything with that soldering iron 🙂
Put the two small SPDT switches onto the PCB. They fit in three holes marked with SPDT ON-ON ON-OFF. You can put them in any way you want. No soldering allowed though.
Lastly, install the PJ301M-12 Thonkiconn jacks in the right spots. Your board should now look something like this. Just one more thing before we can solder all components in place.
So now it’s time finish the job. First put washers on the pots, jacks, and switches. Then put the front panel in place and secure all components with appropriate hex or knurled nuts.
Since the holes for the pots and jacks are a little bit tight, you sometimes need to wiggle a little with a small screwdriver to get them through.
Screw the components only hand tight onto the panel.
If all components are fitted correctly, it’s time to solder them all to the PCB at once. Work methodologically because it’s easy to miss a leg (I know I do). 🙃
One final thing to do now. We need to attach the black knobs to the pot shafts and tighten them with the screw on the side of the knob.
So now all knobs are in place, we finally can start testing the module. So attach the power cable and be sure to put the red strip where the silkscreen on the PCB has a clear striped marking.
All done. Let the fun begin 😄