Hooked it up to the M1 and listened to my standard discs.Sounds very nice, yet not quite as detailed as some of my other equipment. Mind you, these are minor differences and from memory which is notoriously faulty regarding music. That's why I control for that as best as possible by listening to specific discs and tracks from them. Since I don't know this unit's history, I don't know whether it's been sitting idle for awhile and just needs to burn in again, or whether this is as good as it gets with the current caps and opamps. Haven't tried it with vinyl yet, but that will have to wait til I get back from my next trip to GVA. I'd still like to know a little more about the caps that are currently installed, whether original or replaced at some point.