The Tiny TS is a credit card sized (100x65mm) fully open-sourced synthesizer with a 1-octave capacitive touch keyboard.
It has Audio/CV/Gate outputs and 6 synth parameter dials.
The CV’s output 1V/oct and Gate from the keyboard.
With the version 1.1 firmware it now also handles CV/Gate input from a sequencer.
The synthesizer parameter knobs includes: DCO: Coarse pitch and Double. The CV out follows the keyboard and coarse pitch. DCF: Filter peak and ENVmod. ENV: Attack and Release affecting amplitude.
The synth is built on the ATmega328 MCU and is very easy to build as a kit.
The full circuit diagram is as below.
It runs from 6 – 12v (9v battery) but can run down to 3v as well but the CV 1v/oct output is dependent on a 5v supply to the chip.
The PCB is very simple with 1-octave capacitive touch keyboard and a few passive parts.
The BOM for building it:
- IC1 – Preprogrammed ATmega328
- IC2 – 78L05 TO-92 5v linear regulator
- C1 – 100nF capacitor
- C2 – 10uF capacitor
- C3 – 10uF capacitor
- C4 – 100nF capacitor
- C5 – 10uF capacitor
- R1 – 1Kohm resistor
- R3 – 1Kohm resistor
- R4 – 1Kohm resistor
- CN1-CN3 – 1/8″ Thonkiconn Jacks
- P1-P6 – 100K lin Alpha 9mm potentiometers
- The PCB
For more detail: An open-source DIY touch synthesizer