That's pretty damn clever!
I'm quite fond of my fully balanced outputs though, but I know we're pretty much limited to two x OPA1642s (providing 4 op-amps) with phantom power.
Is there a way of making the mixing OpAmp fully differential and blending the rear into the + / - or both via a pot to achieve the same? Thus leaving one OpAmp for inverting the signal to provide fully balanced?
