My ART Opto 8, which I use as an extra 8pre to ADAT into a MOTU 828x (all software and firmware up-to-date) has started doing the weirdest channel hiss.
The output channels are totally unaffected. Given the nature of the hiss across the channels, I'm assuming this is some sort of wiring or power issue? Does anyone know about electrical engineering enough to know? Or have you had this issue before?