.... I fogot to ask this in my previous post .... I understand that the ADC adapter actually allows for the A/D conversion of 8 tracks; four from the unit in which the adapter is installed and four from the XLR ADC inputs on the back of the unit. Of course, in any of the Focusrite literature, the outputs from another ISA 428 are shown connected to these inputs. But am I correct in assuming that there's nothing special or proprietary about these inputs and that they would accept any balanced analog signal and route it through the ADC adapter? Thank you for helping me in my rationalization for spending another $600! Cheers.