alzy101,

Did you ever solve the hiss issue you were haveing with the M200's?

No. They sent me out a swap unit to see if the 2 I had were defective but all three performed the same. I get considerable noise out to a foot away from the speaker. I have owned and tested many power amps over the years and none had anywhere near this level of noise. I believe that a decent power amp should add no audible noise to my system. And it is not my system since the noise is the same whether my preamp is connected or not or on mute.I get the noise with no input connection, just a speaker and power. It is not a hum problem as it is wide band "white" noise. I am returning the units for a refund. All 5 channels of my 755 are dead quiet under exactly the smame set up. The M-Blocks in my opinion do not belong in a quality system. I can't imagine having 7 M-Blocks all hissing away in my otherwise quiet listening room. Should have started with the 770.Thanks for asking.

Well at least you had one solution open to you ( returning them! ). Sorry to hear it worked out that way. I do not doubt that you heard hiss from the speakers and I imagine you did all the appropriate tests to locate it.

While this might be slightly divergent from topic, I wanted to put this out there as it may be of benefit to some.

I live in an older house and while all wiring is in code, the wire placement was not of the best design. I recently had hiss in one speaker. Swapping the speakers ( stero mains ) proved nothing, I still had hiss in the right speaker. Figuring it was the amp, I thought I would take it in for service. The day before I did, I was in the basement and happened to be right below the main stereo room. Above me was a small juction box on the roof of the basement, which was the floor of the stero room. Going back upstairs, I disconnected the speaker, from the amp.

Amusingly enough, I still had hiss. Moving the speaker solved the issue.

Bob045