... How about a standard adc stage with FPGA processing/routing and I2S bus. For ADAT there are already the OPTOGEN and OPTOREC modules (dont have the links right now). Then ADAT and spdiff/aes-ebu as standard interfaces. An optional XMOS low cost board for avb, which is capable of I2S. And a FPGA extension board for MADI and ieee1394 also connected via I2S. I kinda like the idea... could be highly flexible... Second step: same device as DAC... Ck