Aureal Vortex and Vortex2 does work in DOS with modern chipsets for SFX output but has a problem: sound effects would keep looping either just the first few seconds or the entire sound data.

It seems to depend on SBPro IRQ setup on the TSR side (e.g. AU30DOS.INI for Vortex2). This is what I observed on a B75 board with a SQ2500 (Vortex2, AU8830) using DIGPAK setup (SETD):
- If SBPro IRQ set to a different one (e.g. IRQ5 while the sound card itself is on IRQ11), the sound loops for just the first few seconds (about 3 seconds I think).
- If SBPro IRQ set to the same IRQ as the sound card (e.g. IRQ11 with the sound card itself on IRQ11), the sound loops for the entire data.

When the sound loops, no other sound data can be played and the sound could end up distorted if the memory involved gets altered by external means. It will keep playing nonstop AFAICT, until the program exits (in case with DIGPAK's test program, MENU).

I wonder if some IRQ-related tricks might be needed for proper SBPro emulation on Aureal Vortex family cards, despite its tricks for DMA do work with modern chipsets whereas other vendors don't (in most cases no SFX at all, only FM and maybe MIDI). Or maybe there was some known caveats with Aureal's SBPro emulation that may lead to this behavior.

On the other hand, I do remember having positive results on a G41-based board with a Vortex (AU8820) a long time ago. Everything worked perfectly fine there back then AFAIK. No looping. However, the same looping behavior was also observed on nForce-based boards back then, with the same Vortex (AU8820) card.

The only post I could find about how the TSR works under the hood (AU30DOS for example) is this one, though it's mainly about how it emulates DMA and not much about IRQ and other factors.

On the other hand, FM sounds okay with my SQ2500 and MIDI (using a daughtercard) also works fine on the system.

EDIT: A side question. I wonder if it's possible to make AU30DOS only initialize the card's MIDI interface without actual SB/FM emulation, as I'm considering using a PicoGUS in SB mode on that system via dISAppointment, while using the SQ2500's MIDI since PicoGUS 1.2 can't use MIDI daughtercards. Tried setting "SBFMBase=0" but this simply makes AU30DOS refused to load citing emulation disabled.