OPL2 Audio Board

The OPL2 Audio Board

This is a synthesizer board for your Arduino, Teensy, Raspberry Pi or basically any board with an SPI interface and a few extra IO pins! It uses the classic YM3812 OPL2 sound chip. The same chip that was used on the Adlib and Sound Blaster sound cards. You can use it to play back music of your favorite classic games on a real chip, compose your own tunes and whacky sound effects, or play around with the YM3812's FM-synthesis.

December 2021 hardware update

The new updated OPL2 Audio Board hardware has better filtering for improved audio quality and better bass sounds. There is now also a line out to get clear audio directly from the OPL2 chip.

Here is some inspiration for your projects

1. Build your own retro synthesizer or MIDI keyboard. You can use the Piano Board to add a small piano keyboard.
2. Play simple tunes from a string that resembles the QBasic PLAY command
3. Play vintage video game music files (DRO, IMF)
4. Play Reality Adlib Tracker (RAD) files
5. Use it as a real OPL2 with DosBox
6. Use it as a MIDI device (requires Teensy 2.0++ or later)
7. Use it as a synthesizer together with the OPL3BankEditor by Wohlstand
8. Library includes instrument defintions from Adlib, The Fat Man (many DOS games), Windows 3.1 Sound Blaster drivers

What about the hardware and software?

You can choose to get a board fully assembled and tested or as a kit to assemble yourself. For kits I always test the ICs before sending! The kit is very easy to assemble and the software library comes with a bunch of examples to get you started within an hour.

The software is very easy to use and extend so you can incorporate it into your own projects without too much hassle. The OPL2 library allows you to:

1. Get easy access to all of the OPL2 registers
2. Every OPL2 setting is exposed as a separate function
3. Load predefined instruments or create your own
4. No need to do any bit twiddling, or calculate register offsets

Since I don't like to discriminate between development platforms the software is the same for Arduino and Raspberry Pi like boards. It is easy to switch between target platforms by changing a variable. By default platform is set for Arduino, Teensy, Node MCU, etc. For Raspberry Pi, Orange Pi and other Pi like boards an installation script is provided that will take care of all the hard work to compile and install the library.

Audio quality of the OPL2 Audio Board is great, although I recommend using it with active (amplified) speakers for the best results.

Before shipping the chips in each kit or assembled board are tested to confirm that they are 100% working. Please be aware that YM3812s are no longer in production and therefore you will receive chips that have been recycled, but tested to be fully functioning.

Enclosure

I now also offer a 3D printed enclosure for your OPL2 Audio Board. The enclosure comes as two parts printed in stylish Vertigo Grey PLA and 4 screws. Please note that if you order an assembled board with the enclosure that you will still have to put the board into the enclosure yourself.

If you want to print the enclosure yourself then you can download the STL files here: https://www.printables.com/model/263388-opl2-audio-board-enclosure/files.