Shruthi - DIY resources
This section contains all the information allowing you to build your own Shruthi or hack its firmware.
The Shruthi contains two section: a digital section (“control board” or “digital board”), containing the display, main microcontroller, switches and pots ; and an analog section (“filter board”) hosting the VCF, VCA, input mixer and the output stage. Several variants of the filter board are available to provide a broad range of sounds.
- Schematics, BOM, and assembly instructions for the control board.
- Schematics, BOM, and assembly instructions for the XT control board.
- SMR4 mkII, a solid, Roland-ish, 4-pole filter.
- LP2+Delay, the combination of a MS-20 LPF and a low-fi digital delay.
- 4-Pole Mission, a 4-pole multimode filter inspired by the Oberheim Xpander.
- Dual SVF, the combination of two multimode 2-pole filters - in series or parallel.
- Polivoks filter.
- FX/Digital filter board - a nasty, crunchy, digital LPF/HPF and FX section.
- SMR4 filter board (predecessor of the SMR4 mkII).
Mutable Instruments has stopped publishing any information regarding the use of “vintage” SSM/CEM/IR integrated circuits.
To celebrate the launch of new filter boards, limited edition series of kits have been sold.
- Assembly notes for the 4-Pole Mission special edition.
- Assembly notes for the Yellow Magic special edition.
- Filter board assembly for the Midnight special edition (the control board is standard).
- Shruthi XT enclosure assembly instructions .
Here are some files to help you design your own case:
- Export of the Shruthi-1 control board silkscreen, with parts footprints. To be mirrored!
- Blueprint with 3D parts placement by nio101
- A Sketchup export of nio101’s 3D model
- SVG file for the acrylic case.
- Image of the Paisley pattern engraved by default on the cases.
Schematics and PCBs of the filter boards ; and documentation/analyses are released under a Creative Commons cc-by-sa license. Firmware code is released under a GPL3.0 License. Some of the (now deprecated) filter boards had been released under a cc-by-nc-sa license.
The authors of the patch library are listed at the end of the manual.