Sorry I havent updated in a while, I now have some time to start back on this project. Turns out that Via does not want to help out, so back to the drawing board. CEntrance wants $20K/license for asynchronous code, which I dont have, so I dont think thats the best route. I have no idea how to program that chip so I was thinking about something like this:
-tusb2046 usb hub....(1)
-pcm2707..............(4) usb-I2S (bypassing the internal dac)
-pcm1798............(4) I2S-Current (dac)
-ne5534............(24) I/V and summing opamps
It wouldnt be asynchronous but if we can get something physical with whats been already tried and true, thats a step in the right direction. I know that you want interchangeable opamps, but just for proof of concept i want to use the TI recommended. Does anybody know of any issues with having the computer recognize 8 separate channels if a usb hub is used? If not, I am going to go ahead and order the parts and build a rough prototype to ensure that the sound card does what its supposed to do with regards to channel separation and decent output voltage.
Look forward to hearing from you guys.