T. Combriat

8 knobs synths are simple synthesizers based on Mozzi using STM32 blue pill as the main hardware. Thanks to the computing power of these chips, these synthesizers are able to generate complex polyphonic sounds at 32kHz sampling rate. The aim of this serie is to provide a fixed hardware which can be used for different synthesis methods.

• XORAND
• FM synth

These synthesizers feature:

• MIDI input and thru
• 8 knobs for controlling parameters (thus the name), note that one is hardwired for volume control
• 6.35mm audio output (mono)
• standalone power from 3 AA batteries. This ensures cleaner sound thanks to very stable power lines.

PCBs for the chip are single faced and can be easily made if one is able to make 250 microns wide tracks. The mask is provided here for the mono version.

For now, only one version of this synth has been developped: mono output using the chip PWM and a low-pass 1^st filter. Other versions, featuring Mozzi HiFi, stereo, DAC outputs may come.

These synths can be programmed like any other STM32 pills using USB to serial converter. Native USB will usually not work. You will also need a rather new version of the Arduino IDE with Mozzi installed and modify Mozzi in accordance with the beginning of the sketch or use the TES forked version of Mozzi.