Thank You George, I can tell you that when it works it all sounds normal on both channels, although I did not try to testthe channels and speakers separately. Now I cannot test, the amp is at the dealer's frown

News is that my dealer informed me the problem is reproductible when connecting a controller via balanced interconnects to the 557. Seems like connecting the balanced inputs causes the behaviour ?!? While on the unbalanced inputs it workd fine ?!?
I will call M in the UK and try to talk to someone there about this.


M kit : G08 502 557 507 2xDSP5k