Do you know which chipset your board actually has? I am pretty sure BIOTEQ is just branding.

Yes I do, it's a UMC 82C3491 based mobo 😀
TLB works wonders with that and give me ~160kb of UMBs to use, ultra-helpful as the OPL4 driver is ~30kb :\

I've been digging more into the SW20-PC OPL4 control panel options and it struck me: what if you could have both OPL4 + FM synthesis play at the same time? Well you can! What I found more interesting is that you can play for example a midi file using the FM synth but have the percussion channel play though the OPL4 synth, giving very interesting results. I wonder if there are any compositions that use OPL4+FM+Samples loaded to SRAM, I am pretty sure the end result would be really good.

I also noticed that the Voyerta AudioStation player app has a mixer app specific to the SW20-PC , the Dry/Classic/Jazz/etc buttons load DSP profiles and pitch/feedback/depth controls work and pass variables to the DSP directly. I totally forgot about it, I just assumed it was a stock player.

now I remember why I kept the card and it's whole package 🤣 , it is something I did not do when I was younger, I have binned stuff that worth good amount of money today... now I am on the opposite side, I don't even bin generic packaging 🤣

Made some recordings using the Sound Edge and the midi files from WinRoids - a great and freeware asteroids clone for win3.x .

It's nothing serious, the midis do have flaws in them and this was done for fun since it is a game I was playing back then, mainly to test how good replacing some midi channels with FM synthesis sounds will sound.
So I just assigned lead instruments channels from OPL4 playback to OPL3 playback. The result is better to my ears but this was just a fun thing to do 😎

Dreams.mid GM playback
Dreams.mid GM+FM playback
Winroid2.mid GM playback
Winroid2.mid GM+FM playback
Winroids.mid GM playback
Winroids.mid GM+FM playback