The TinyTS – DIY Synth


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.


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 potentiometer

You can get the PCB + preprogrammed chip here:


And the files for printing your own casing are available here:


Building Instructions

1. Get the PCB and all the parts out.


2. Solder the 3pcs 1Kohm resistors.


3. Solder the capacitors as shown in the picture. Mind the polarity of the black 10uF caps.


4. Solder the IC1 ATmega328 MCU (or a socket if you want to reprogram it).


5. Solder the IC2 linear regulator.


6. Solder the P2, P4 and P6 potentiometers.


7. Solder the P1, P3, P5 potentiometers and the Thonkiconn 3.5mm jacks.


8. Finally solder the 9v battery clip.



Get a 9v battery and plug some headphones in the Audio Out jack to check if it works.

The code

Ok, so I want to code it myself.

This code runs on a standalone ATmega328.
You can use it with taped keys or even play the synth directly off the legs off the DIP chip.

But I rather like you to at the least get the PCB for it.

Here goes: