JonDent - Exploring Electronic Music: DAFM synth

Saturday 14 December 2019

DAFM synth - DIY build notes

My unofficial build notes for the DAFM synth.

I am in no way associated with the developer. These are just my personal build notes to help me trouble shoot, should I have any problems.
The designer is KASSER SYNTHS from Spain.

The DAFM uses the YM2612(OPN2) and it's CMOS variant the YM3438.
The 2612 was used in arcade machines, the Sega Mega Drive/Genesis home game console (1988), and the Fujitsu FM Towns (1989)
It's a FM/PCM hybrid chip
The chip can have either 5 or 6 FM channels.
(5 FM channels with 1 PCM or 6 channels without PCM)
The YM2612 has six channels with four operators per channel.

tHE build is super easy. All parts are supplied and well labelled. If you can follow a recipe and know how to hold a soldering iron, you can build this.

There are 8 algorithms. The envelopes, frequencies and LFOs can be changed to get a good range of FM sounds.

The midi section is on the top left. A standard DIN connector.

Thats a MPR121 breakout pcb on the lower right.
It's a capacitive touch sensor controller driven by an I2C interface... probably what controls the cube keyboard.

Presets can be saved in the RAM memory or in a SD card as DMP files that can be opened with VGM trackers like Deflemask.

The top right section... LD33V power regulator & USB - type B, female.
The USB connector is the power supply of the DAFM synth
The LD33V powers the touch sensor

Also added the two lower encoders.
These are used to move through the DAFM Synth menus.

That pink board is the audio preamp.

The 8 MHz Crystal oscillator ... for the timing.

keep the dot on the bottom left.

This second pink PCB is a multiplexer.

It lies between the SD card & the DIN socket.

This TCA9548 I2C Multiplexer connects to the four OLED displays.
The four OLED displays share the same I2C address.