I've just tried using a fresh Dell XP install disc, and LegacyUpdate paired with the official drivers for the Precision 690, and still no dice with this thing. I had read on another forum a while back that some chipsets apparently had really big problems with Creative products, particularly the XFi series.

I also came across this documentation in the HP xw9300 manual, which I attached below. It mentions that you cannot use the SB0460 with the Quadro FX 4500, which I found odd.

My Precision 690 is currently using a Quadro FX 3500... So maybe that's the issue? For some reason?

So, I tried with an X1950 Pro instead, no difference. I read up on this thread however:
https://www.overclockers.com/forums/threads/s … to-work.626226/

This guy seems to go into fairly exhaustive and excruciating effort to try and get this card working on his system. He's got an nForce 570 SLI chipset on his board. My chipset is Intel 5000X, but it does support SLI too. Maybe that has something to do with it? I'm kind of in the same boat he ended up in now, it looks like. I wonder why it's just refusing to work properly no matter what.
There has to be a solution since Dell shipped these Precision 690's with SB0460's as an option..

No help, but I feel your pain; when I upgraded to a P5Q Pro back in 2008, my trusty Philips Acoustic Edge sound card would not work with it. It worked fine with the preceding 5 motherboards, but it refused to work with that one.

Yeah, it's very frustrating.

In a bout of good news perhaps, though, I popped in my SB0230, loaded up the KX drivers, and it seems to work okay, however I can't figure out how to get the SB0250 front panel or digital i/o settings working using it. I might just not know what I'm doing, though.
If I can get all that to work, I'll probably just get a ZS 2 and use the KX drivers and call it a day.

The 2 ZS drive doesn't work properly because it has a different pin out for the connector. AUD_EXT connector on the Audigy sb0230, and AD_EXT on the 2 ZS drive. Just noticed a couple hours ago. Ordered a 2 ZS off eBay and hopefully will be off to the races.

Been listening to music all day on the rig otherwise though, very stable now. I guess the solution to the Intel 5000X chipset is just "don't use X-Fi, 🤣". A shame because the Xtrememusic is a little better for what I'm trying to do (rompler music production), but what can you do?

Closing update:
SB0350 (gold connector version) works perfectly with kX drivers and the 2 ZS livedrive in the Precision 690. I had to use the version 3552 signed drivers (3553 unsigned didn't work) on my setup with XP sp3 32bit.
I also had to manually copy and paste the kX.sys file from the program files kX folder to system32, since it was just throwing a "kX device not found" error.
It's actually better for my use than the XFi with Creative drivers, since you have full DSP control, and can intercept and record a 24/96 digital input before it reaches any resampling, with the kX drivers, by taking advantage of the P16V unit.
Though apparently it is worse for old games due to worse resampling, and older games often using lower sample rate. I don't really game though on it much just music production stuff.
Anyways, if anyone else is using an Intel 5000X chipset with Creative stuff I hope this helps.