I'm a huge fan of the OPL2/OPL3 sound chips, having played a lot of DOS games as a kid which used these chips for music and sound effects (via SoundBlaster sound cards). So naturally, I was very happy to see various OPL-based products appear in recent years, like the OPL2LPT or ArduinoOPL2. However, the Retrowave OPL3 is the first one that is really easy to use with a modern PC thanks to the PotatoPi interface board, while also allowing use with a Raspberry Pi via the GPIO interface if desired. On top of that, the sound quality is very clean - they aren't exaggerating when they say it's audiophile focused!
So, if you're into using a real OPL2/OPL3 sound chip with modern machines, I can highly recommend this product.
I've bought this because I mainly play old DOS games. Even those only from time to time since I'm 42 and life is not the same as it was when I was a teenager. But the sound of this board brought me back to the times I played Heretic and HeXen. The board works out of the box in Windows (just check the COM port of the USB PotatoPi Lite board when configuring). In Ubuntu 20.04.2 I did not manage to make it work yet and haven't yet tried it in conjunction with a Raspberry Pi, although I'm planning to build a DOS games machine. DosBox-X has support for RetroWave out of the box. There is a volume knob on the board itself.
Does what its says on the tin. Got v2.0 and it sounds good (or at least about as good as these old chips are supposed to sound ;). Provided software example (VGM player) with the potatopi adapter works out of the box. Documentation is a bit terse and figuring out some things needs inspection of the source code, but at least there's (open source) source code, so that's good. I feel like shipping was a bit slower than it needed to be, even in covid times, but it got here in one piece. Packaging was good.