I think it might be a Crystalake model 2xx card, something like Crystal Clear Wavetable from this thread, but sans the SBPro part.

As the photos of Crystal Clear Wavetable aren't there anymore, we might need to summon swaaye in hope that he can say something. I just wrote him a personal message.

swaaye wrote:

Also found that there were some "wavetable upgrade" cards that people bought to attach to motherboards. Sounds like a DB that fits in a slot, maybe like that AWE upgrade card. They were Model 2x0.

Hey guys. I think I am going to be useless. 😀 I forgot all about that card I had in that thread Bristlehog dug up. I never did get it working. It was a PCM + MIDI card though, unlike this MIDI-only card. I couldn't get the MIDI to work.

It seems that I was mistaken and this is not a Crystalake 2000 wavetable upgrade card. That card used a 8-pin connector in addition to a 8-bit ISA slot, and had no audio outputs, as shown on an attached picture. It was discussed here.

Also, Crystalake usually put their silkscreened logo on the cards, which is not the case here.

Seems odd they decided to include a game port.

That gameport only has MIDI TX and RX connected, none of the controller signals.