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My stripboard KS-20 filter clone

My modular synth has been in need of a filter for a long time now and a MS-20 VCF clone is an obvious choice loved by many, which is no suprise as it does sound absolutely amazing. However I didn’t find a good stripboard layout online that would fit on the 24-row boards I use so I decided to design my own.

I started out by building René Schmitz’s popular MS-20 clone on a breadboard just to get a better understanding of the circuit and to see that it works. Then I stumbled upon the KS-20 by Kassutronics, which has an added circuit to blend between the low- and highpass modes as well as a drive knob for the input. I added Kassu’s additions to my breadboard circuit, tested them and started working on a stripboard layout in DIYLC.

You can find Kassu’s schematics here.

Stripboard layout

KS-20 stripboard layout


Part Value
R8, R9, R10, R11 220
R24 1k
R22 1k5
R13 2k
R3, R20 4k7
R1, R2, R5, R6, R7, R17 10k
R14 47k
R4, R12, R15, R16, R18, R19 100k
R21 220k
R23 470k
C1, C2 1n
C10 4n7
C5, C6, C8 100n
C3 470n
C4, C9 10μ
D1, D2 LED
Q1, Q2 2N3906
U1 LM13700
U2 TL072
U3 TL074
RV1, RV2, RV3, RV4 100k lin
RV5 10k lin
RV6 1k

The changes I made to Kassu’s design:


Here’s the template I used to make the panel: ks20-panel.pdf (0.0 MiB)

Timelapse video of building the module

I took a bunch of pictures with my phone while soldering the module, lined them up in GIMP and converted them to a video with FFmpeg. I think it looks pretty cool.

The finished module


The 14hp panel I made is pretty chonky and the module could have probably fit into 10hp but it looks nice and it’s good to have a bit of space for my fingers.


Sound clips

Here are some clips of me sweeping the frequency knob with increasing amounts of resonance.


Bandpass (LP/HP pot at 50%)



You can find more info on the MS-20 filter and various DIY versions of it at