Not long ago I acquired a small lot of computer parts that included this Aztech sound card. It was in a pretty rough shape, obviously pulled from a computer that has been exposed to the elements for quite some time. Fortunately, only the top side had corroded and its effects seemed manageable, as I couldn't find any loose pins on the main chip or any crumbly solder joints in general.

Gave it a first cleaning pass with a soapy water and after that, exposed each solder joint individually to dilute hydrochloric acid using a plastic straw of a Q-tip. Majority of the solder crust dissolved around the ICs after the first pass, gave it a quick buff with a short bristled paint brush smeared with mildly abrasive toothpaste and after all that it was in good enough shape for testing.

Installed this card on a SS7 PC with Win98SE, manually set up the latest win9x drivers and it started working right away. The digital portion of the sound card worked as intended, but FM synth was badly distorted on both channels. Distortion was caused by a dried out EC12 cap, which had dragged OPL's DAC Vref voltage from 2.5V down to 1.58V. Card had four more dried out caps, but they didn't affect the sound output in any noticeable way. After the sound card was finally confirmed to work properly, I began the final stage of the restoration - gave it a second etching pass with acid and polished everything with a dry linen cloth that had been soaked in fine abrasive. Unfortunately, some moisture got under the solder mask and it corroded the PCB traces in some areas, not much can be done about that from a cosmetic standpoint.

The line output of this card is surprisingly clean compared to other SB16 compatible cards, although the speaker output emits fair amount of noise that is present in the PSU's power rails, eg. it picks up noise induced by the HDD activity. I didn't run too many tests to determine its compatibility with games, but it passed the two tests that I commonly subject ISA sound cards to. One test being whether stereo mode is functioning in Jazz Jackrabbit in SB Pro/SB16 modes, other being whether WAV sound effects generated in a rapid succession are not being skipped in Diablo.

While I was trying to figure out the exact model of this card so that I could source matching drivers for it, I stumbled upon this entry on DOSDays (search for ABI/ABO). Aztech cards accept a proprietary wavetable module called "WaveTide", thus it's possible that the 26-pin wavetable header labeled as "MIDI" may also have a proprietary pinout. I traced both headers to find out their exact pinout and it looks like that the 26-pin header is just a bog standard wavetable header 😀

I've never owned an Aztech card before, but this one definitely left a good impression on me.

Pinouts of MIDI and EXPCON headers: