Hey, Audiohead - What you want to do may work, here are the possible snags I would watch for:
1. Soundblasters are not known to play nice with other audio cards, so if you encounter any glitches, pops, headaches, diahrrea, etc, this would be the first suspect to round up, shoot, and interrogate.

2. Assuming that you do get the two cards to play peacefully, when you feed the SPDIF of the SB into the Audiophile, you will have to use the clock of the SB to run the Audiophile, which will most likely downgrade the quality of sound you get from the Audiophile. This doesn't mean it won't work, just not as clean as using the audiophile alone or with higher quality friends. You would need to set the Audiophile to take its Word Clock from the SPDIF input so that both cards are synced to the same source, or there will be pops/clicks/pukes...

3. Once you get past all that, you mentioned "I need be able to monitor the mix with a couple of headphones " - The MX602 only has one headphone output, and their downloadable manual makes no mention of the drive capabilities of the headphone output. If you try to connect two sets of phones thru a "y" cable, you will be loading down the output, which will at least cause a drop in levels available at the phones. It could also fry the headphone output amp, depending on how Behringer has implemented their output driver circuitry. The diagram they provide is just a block diagram, so it isn't possible to tell from that whether the single output will drive two phones or die. You could wire a special SERIES "y" cable, and plug one headphone into each plug, but since this board doesn't have graphics capability, you would have to email me and I could send you a diagram of how to do this. It would mean that both sets of phones would have to be plugged in for either to work, and each would be 3dB quieter than just one set would be, but it wouldn't fry your mixer.

4. Using the "tape in, tape out" jacks is the normal way to connect to a DAW - if you think of the DAW, specifically the sound card, as a "tape" recorder, it makes sense. Just remember to turn off "monitor while recording", or whatever it's called in your software, or you'll most likely get feedback and/or unintentional "sound-on-sound" - Since you didn't mention what software you will be using, I can't tell you where to do that.

Those are the only points I can think of that may cause problems, but I think you should be able to make it work. The biggest problem may be the SB live - I haven't used one, but have seen numerous comments about it, none good as far as DAW's are concerned. I hope this clears up your questions, if not you know what to do... Steve

Thanks Steve,

At last an answer, albeit posthumous, since during this time I've bitten the bullet, bought that 602 mixer and answered my own questions by trial and error. I guess I owe you a couple of words summarizing my reasoning and the results.

>Soundblasters ...would be the first suspect to round up, shoot, and interrogate.

In this particular order? :)