We are now looking into the input amplifier and DSP input stage design. A gain amplifier is needed to give the signal enough amplification to fill out the 1V range used in the DSP engine. At present, the USB audio interface will handle 48 kHZ/16bits. For any higher range, and we are looking at 192kHz at 24bits, but that will require an external CODEC. Planning this prototype to get things going.