Reply 20 of 23, by BeastOfSoda
I'd like to share for posterity that I literally just troubleshot a similar problem. My situation is a little different, though: I have an ESS1868f that I normally just use for MIDI (going out to a DreamBlaster over gameport), and an SB16 that is only used for OPL.
I was having an issue when playing a game with PCM audio, since of course the SB16 is plagued by the DMA clicking bug (this means that any sampled audio played through it has a noticeable clicking artifact): in order to get around it, I thought I would try using the ESS for PCM instead, but I noticed right away that the output was quite disturbed (especially when the MIDI events were being fired).
After some faffing, I found out that the culprit was the OPL itself on the ESS, even while it wasn't being used: turning the volume all the way down only for the FM portion and setting the OPL address to F0 via Unisound quieted it right down., and now I have pristine sound across the board.