OPL2 Audio Board
The OPL2 Audio Board is a full OPL2 synthesizer 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 Adlib and Sound Blaster sound cards. You can use it to play back music of your favorite classic games on the real chip, compose your own tunes and whacky sound effects, or play around with the YM3812's FM-synthesis.
Features of the OPL2 Audio Board
The OPL2 Audio Board is a very flexible OPL2 synthesizer that thanks to its software library is an easy to use platform for your own synthesizer or gaming music nostalgia projects.
- Extend the OPL2 registers to external controls to build your own synthesizer just as you like it
- Play simple tunes using the tune parser that comes with the library
- Play vintage video game music files. The library comes with examples to play .DRO, .IMF and .VGM files
- Use it as an Adlib tracker. The library comes with an example to play .RAD files
- If you have a Teensy 2.0++ or later then you can use the OPL2 Audio Board as a MIDI device. A MIDI device implementation is included
- Experiment with FM synthesis and create your own OPL2 instruments using the OPL3BankEditor by Wohlstand
- Use the board as a real OPL2 with a special version of DosBox
- If you have a Piano Board you can make your own mini keyboard
About the OPL2 chip
The YM3812 or OPL2 audio chip was a very common FM-synthesizer chip found in PC sounds cards such as the Adlib and Sound Blaster during the early 90s. It has a very distinct sound that many PC users from that era will remember fondly, whether from playing DOS games or listening to MIDI files in Windows 3.1.
Capabilities of the OPL2 include:
- 9 channel FM-synthesis
- Percussion mode with 5 built-in drum sounds (leaves 6 FM channels when enabled)
- Each FM channel has 2 operators
- Custom ADSR envelope on each operator
- Per operator volume control
- 4 possible waveforms on each operator (sine, half sine, absolute sine and quarter sine)
- External Y3014 DAC to produce the audio
OPL2 library software
In order to use the OPL2 Audio Board with your Arduino, or compatible board, you need to install the OPL2 library that can be downloaded using the library manager of the Arduino IDE or PlatformIO. You can also download the library yourself from the Github repository. For Raspberry Pi users a build script is included in the repository that will install the library and compile the code exaples.
The library comes with many fun examples that will show you how you can use the OPL2 Audio Board and they can be a great start for your own projects!
Purchase a kit!
You can get the OPL2 Audio Board from my Tindie store either as a kit that you put together yourself, or as a fully assembled board. You have the choice between using a 3.5mm jack or 3-pin speaker terminals for audio output and the choice between straight or angled headers to connect the board (assembled boards will always have angled pin headers!).
Kits are shipped to you in a quality white cardboard box that will fit in any normal letterbox. All the components you need to put the board together are included as well as spare YM3812 and Y3014 chips if you ordered the kit with spares. A small instruction booklet contains a brief assembly guide and points you to my Github page where you can obtain the OPL2 library software.
Please be aware that the YM3812 and Y3014 chips are no longer in production and therefore you will receive chips that have been recycled. Before shipping the chips in each kit or assembled board are tested to confirm that they are 100% working.