We’ll populate only the top of the board – it’s the side with the DAFM Synth and Genesis YM2612 / YM3438 logos. Here’s a shot of the completed board for reference.
220Ω x 2 (red, red, black, black, brown)
Resistors are not polarized, so it doesn’t matter which way around they go in. Bend the legs into a staple shape,and fold the legs over once you’ve inserted them into the board.
You don’t need to fold them over too much, it’s just so they don’t fall out when you flip the board over. It’ll make it easier to solder and snip off the legs if you don’t.
4.7kΩ x 1 (yellow, violet, black, brown, brown)
Solder and snip.
The 1N914 has a see-through glass body. It is part of the MIDI input circuit. Solder and snip. Watch out, the diodes are polarized, so pay close attention to which side the line marking on the diode body goes – it’s marked with a thicker white line on the PCB.
5 Pin DIN Connector
8 Pin Socket
It’s for the 6N138 optocoupler. The side the notch goes is marked on the board by a broken line on the ICs outline.
It is used for saving and loading instrument presets in the DAFM synth.
Capacitive touch sensor used for the beautiful tactile keyboard of 12 notes.
Place the pins on the PCB and then place the MPR121 breakout.
Solder the top part of the pins to the MPR121 breakout and then the bottom part of the pins to the DAFM synth PCB
5Rotary encoder with switch x 2
Used to move through the DAFM Synth menus.
65V DC Power USB Type B
Female connector for the power supply of the DAFM synth
7LD33V Voltage regulator
3.3V voltage regulator for the MPR121 touch sensor. It’s polarized, but with the legs bent the way they are, there’s really only one way it can go in. Make sure it’s flat against the board before you solder and snip.
2.2kΩ x 2 (red, red, red, brown) ONLY FOR YM2612 CHIP!!!
You’ll need 1 each for the left and right sound output of the YM2612 (do not use for YM3438). Solder and snip.
24 Pin Socket
It’s for the YM2612 or YM3438 chip. The side the notch goes is marked on the board by a broken line on the ICs outline.
8 MHz crystal oscillator
Clock for the YM2612 or YM3438 chip. The pin on the bottom left with the point corresponds to the pin 1.
⅛” Mini Jack
Audio output for headphones or to connect to an external amp.
2200 μF Electrolytic Capacitors x 3
Watch out – these are polarized. The white, gray or gold line marked with minuses on the side of the cap indicates ground. On the board, the ground side’s pad is the white part on the side. I usually tack one leg with solder, heat it up and straighten it, then solder the other leg.
B103 Stereo Potentiometer with switch
Used for turn on / off the DAFM synth and control the audio volume.
TDA1308 Audio Preamp breakout
Amplify the sound output high enough to use headphones or to connect an external amp. Solder it the same way as the MPR121 breakout.
TCA9548 I2C Multiplexer
The four OLED displays share the same I2C address, therefore an I2C Multiplexer is required. Vin is pin 1 which is marked with a square. Solder it the same way as the MPR121 breakout.
0.96 I2C Monochrome OLED Display breakout x 4
Solder them the same way as the MPR121 breakout.
10Header for serial connection to STM32F103C8T6
Solder the header as shown in the picture