McIntosh SS Owners Question

Yes amp to power conditioner I was minus the ground plug.

from the amp

That reminds me I used a PS Audio PC with the ground plug removed. Sorry I had forgotten to mention that, old age memory lapse.

Was the hum coming from the speakers or the amp itself? If the former, you probably have a ground loop issue.

Lots of discussion here on AG if you enter "ground loop" in the search field.

I unplug my Power Conditioner and plugged it into a different outlet. Hum gone.

I had a MC7205 which is the same chassis as the 206 Sans 1 channel. I had the same hum and determined that it was the power supply resonating through the shelf. I found some ModSquad rubber feet that eliminated the hum. Those are no longer made but a similar foot such as sorbathane etc may be your solution as well.

Agreed. There should be no hum at all. Have it checked out.

Your MC206 should be dead silent, no hum. Is this a 60hz line hum by chance? If so check you AC line. Also make sure there are no dimmers on the same line.

They are excellent amps. I hope all goes well keep us posted.

Best,
hififile