A few of the older Aztech Sound Galaxy cards are non-PnP as well. […]
A few of the older Aztech Sound Galaxy cards are non-PnP as well.
See here for a mostly complete list of part numbers.
You will have to research specific part numbers.
I'm also a fan of the Aztech based sound cards.
However, the list in the above link is incomplete.
Personally, I would go for any Aztech card with the AZT-2316 based chipset. They are less noisy than the earlier models, are still non PnP, provides very good Sound Blaster Pro II compatibility and has a real OPL3 synthesis chip onboard. Avoid the ones with the AZT-1605 chipset, since they don't support Sound Blaster Pro digital sound playback (only Sound Blaster 2.0 mono).
For older PC's (like a 286 or a 386), you could also look at the first generation models, like the NX Pro, NX Pro 16 & Basic/Pro 16 (I38-MMSN810). These models still has the low pass filter "built in" and are therefore very good Sound Blaster Pro clones. Only downside is that these are a bit noisier, but not more than a real Sound Blaster Pro.