Greetings, Great thanks for the help, folks ! I've switched out the Omni I/O for the simpler box, audio is back on track now. Clearly the Omni is the culprit, it lit up when there was nothing connected to it. It's a handy unit, I'd like to keep it so I'll see about getting it fixed. Ah, warmth and noise, it's all good again. Best regards, dp