Summary of An open-source DIY touch synthesizer
The Tiny TS is a compact, credit-card-sized open-source synthesizer featuring a 1-octave capacitive touch keyboard and six parameter dials. Built on an ATmega328 microcontroller, it supports CV/Gate input/output for sequencing and operates on 6–12V power. The project includes a simple PCB design and offers Audio, Control Voltage, and Gate outputs, making it an accessible DIY kit for electronics enthusiasts.
Parts used in the Tiny TS:
- 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
Story
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
- What are the dimensions of the Tiny TS?
The device is credit card sized at 100x65mm. - How many dials does the synthesizer have?
It features 6 synth parameter dials. - Does the firmware support external sequencers?
Yes, version 1.1 firmware handles CV/Gate input from a sequencer. - What power supply voltage does the unit require?
It runs from 6 – 12v using a 9v battery but can operate down to 3v. - What type of MCU is used in the build?
The synth is built on the ATmega328 MCU. - Can the CV output function if running below 5v?
No, the CV 1v/oct output is dependent on a 5v supply to the chip. - What specific controls are included in the DCO section?
The DCO section includes Coarse pitch and Double controls. - What components make up the BOM for the circuit?
The BOM includes ICs, capacitors, resistors, jacks, potentiometers, and the PCB.
