I recently got one of these triangular ESS AudioDrive ES1868F cards, so I thought I'd drop by this thread and share my experiences in a mini-review.
Drivers
In pure DOS, I'm using the 1868 drivers from this pack. Under Windows 98SE, I'm using the VxD drivers (185xw95.zip) from Phil's website. The stock WDM drivers which 98SE installs by default didn't give me good compatibility when running DOS games from within the Win98 DOS prompt, but the VxD ones work perfectly in that regard. I also love how simple it is to configure everything in DOS using ESSCFG.EXE and ESSVOL.EXE. No messing around with PnP utilities like Creative's CTCU/CTCM and Intel's ICU. I've configured the card to use IRQ 7 in both Windows and DOS and muted the mic, aux and line in since I don't use them at the moment. Everything else, I left as is.
ESFM
The FM synthesis on this card sounds excellent and gets very close to a genuine OPL3, at least to my ears. I'd even say that ESFM sounds a bit less "buzzy" and more melodic than true OPL3 which, while different, can produce a more pleasing result on some tracks. Personally, I'd rate it higher than Creative's CQM any day of the week. And for people who are more into General MIDI, the wavetable header on this triangular 1868F that I'm using is rotated by 45 degrees, meaning that it can easily host even the largest wavetable daughterboards.
SBPro mode in DOS
I'm very impressed by how clean and vibrant digital audio sounds in SBPro mode. It also seems to have very good compatibility even with older DOS games. The ES1868F supports ADPCM so Duke Nukem 2 sounds as it should. I've also noticed that older DOS games which use 11 KHz audio samples sound nicer on this card than on some others which run at 48 KHz natively (e.g. SBLive). I'm guessing that since the ES1868F is a native 44.1 KHz card, it handles resampling much better. It's also worth pointing out that this card is completely noise-free with the jumper set to Line Out position.
AudioDrive mode in DOS
In theory, this mode is supposed to bring 16-bit audio quality to DOS games which support it. In practice, the situation isn't so great. From my experience, games which use the HMI sound system (e.g. Tomb Raider, Descent, Daggerfall, Red Alert...) produce muffled sound when the AudioDrive option is selected in setup. Phil demonstrates this behavior in his review video around the 7:08 mark.
For other games that use the Miles sound system, I found that selecting the "ES688 Digital Audio" option (using ADRV688.DIG) wouldn't work on my 1868F card. It simply fails to detect the chip. However, in a few late-era games like Heroes of Might and Magic 2, there's an updated driver called just "ESS AudioDrive" (using AUDIODRV.DIG) which does work on the 1868F and produces nice, clean sound. This AUDIODRV.DIG file can be copied over to older games and using that driver usually enables them to recognize the card giving improved sound clarity. However, in certain cases (e.g. WarCraft 2) it can instead produce inferior, muffled sound which sounds far worse than the SBPro mode.
I'm kinda curious if the AudioDrive mode works better on older ESS cards such as the 688F or the 1688F. Can anyone who has one of those try it and see if it produces muffled sound? Good games to test are Tomb Raider, Descent, Mortal Kombat 3 and WarCraft 2.