Sound Card with Multiple Stereo Outputs

Lynx AES16 best drivers with Aurora16 with Antelope Isochrone ocx + 10M
and the best digital wordclock cables you can buy.

or instead of the Aurora16, any other brand
like RME adi-8QS, Mytek 8x192, 8x96, redbox, digi 192hd, apogee, etc...
every ADDA sounds diferent becouse the analog circuit design & components.

cheaper options are the MOTU 2408mk2/3, with pci324/424
or Firewire like several RME FF800.

you can have mutiple cards for more i/o than you can ever use.

the redbox rb-adda sounds nice, has great analog circuit.
to me sounds better than prism.
just download hear the 3daudioinc com ADDC CDs.

some people swear about the DAD converters are the best, havent heard direct A/B tests against Lavry Gold

but lavry gold to me ... WOW the sound i like.
but have latency issues..
and long start up calibration times.

Re-reading your question, you should not go with 1/8" stereo jacks for outputs. Professional cards use 1/4" TRS jacks (mono) in pairs. They are balanced outputs and sound much better.

I run a professional project studio and record high resolution audio (up to 24bit/192kHz). There are several options, depending on your budget. Keep in mind that with multiple outputs, you need multiple DACs, so to get really good quality, you need to pay up. Here are my best recommendations (by manufacturer -- check their websites for the design you want):

- RME
- Apogee Ensemble
- Lynx
- Prism Orpheus

Prism makes $10k DACs for professional mastering suites. Their Orpheus goes for around $5k, and is unbelievable. A more modest option is the Apogee Ensemble, which mates beautifully with the Mac and is the easiest to set up. I use this. It runs about $2k. RME is also excellent, and perhaps cheaper depending on configuration.

M-Audio is now part of Digidesign (makers of Pro Tools), and is their lower-end sister. The equipment is good for the money, but by no means high end.