The OPL3 Duo is a very flexible synthesizer board for your Arduino or compatible dev board that gives you almost unlimited possibilities to play with OPL2 and OPL3 music synthesizers. The board has two YMF262 OPL3 chips that give you double the capabilities of a single OPL3. The characteristic sound of the OPL3 will be instantly recognizable for anyone who has played PC games in the 90s. This synthesizer allows you to recreate these nostalgic sounds and go far beyond what you thought was possible with OPL2 or OPL3 synthesizers!
Features of the OPL3 Duo
The OPL3 Duo gives you almost limitless possibilities to play with OPL2 and OPL3 audio synthesizers. Whether you want to build your own MIDI synthesizer, playback tracked music or video game music files, or experiment with the OPL3 chip, the OPL3 Duo can do it all!
- Works with any Arduino, Teensy, Raspberry Pi, Node MCU, or other Arduino compatible boards with SPI and 5 free digital IO pins
- Works with either 5v or 3.3v
- Fully OPL2 compatible
- Up to 36 2-operator channels
- Up to 12 4-operator channels and 12 2-operator channels simultaneous
- Up to 10 simultaneous drum sounds in percussive mode
- Stereo audio through 3.5 mm jack, amplified speaker out and unamplified line out
- Software compatible with the OPL2 library for Arduino and the OPL2 Audio Board
- Library software that comes with simple and fun examples to experiment with that will show you what your OPL3 Duo can do:
- OPL3 synthesizer basics
- TuneParser that plays music from simple text strings
- Playing MIDI (Requires a compatible Teensy)
- Playing popular game audio files
The OPL3 Duo board in action
These video demonstrates the OPL3 Duo playing some MIDI files from popular games. The MIDI interface is provided by a Teensy 3.6 and the files are played using the MIDIBar application. The code is available as one of the examples in the OPL2 library.
The YMF262 OPL3 chip
The YMF262 or OPL3 audio chip was a very common FM-synthesizer chip found in PC sound cards such as the Sound Blaster 16 during the 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.
The OPL3 chip has the following capabilities and these are doubled by the OPL3 Duo!
- 18 channels of 2-operator FM-synthesis
- 12 channels can be grouped to create 6 4-operator channels
- Percussion mode with 5 built-in drum sounds (Uses 3 FM-channels)
- Fully compatible with the YM3812 OPL2
- Custom ADSR envelope on each operator
- Per operator volume control
- 8 Possible waveforms on each operator
- 2 Or 4 possible synthesizer modes for 2-op and 4-op channels respectively
- Stereo sound output
OPL2 library software
The OPL3 Duo uses the same software library as the OPL2 Audio Board and is therefore fully compatible! The library has all the extensions for the OPL3 Duo to unlock its OPL3 specific features. Though the OPL3 Duo has two YMF262 chips on board your software can simply address the board as if it's one OPL3 chip on steroids with 36 channels! But if you want full control over each individual chip then that is of course, also possible.
In order to use the OPL3 Duo 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 examples.
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!
Get your own OPL3 Duo board
The OPL3 Duo board is available for purchase from my Tindie store. The board will be pre-assembled, tested and is ready to go as you receive it.
The board is shipped to you in a quality white cardboard box that will fit in any normal letterbox and is well padded to prevent any damage during shipping. It comes with a set of adhesive feet that you can stick on the bottom. A small instruction card is provided with each order to point you to the OPL2 library software and to help you to connect the board to your dev board of choice so you will be up and running within an hour!