Thanks for the replies. I did call Mcintosh directly, they are indeed helpful (the input impedance does not change in mono mode, and they agreed there is no need to match the tubes or age of the amp).
Re the speaker impedance, yep, I'm sure about the number. The speakers are Martin Logan Summit electrostat hybrids. ML specs say 4ohms nominal, min 0.7ohm at 20KHz.
Regards
-steverw
Re the speaker impedance, yep, I'm sure about the number. The speakers are Martin Logan Summit electrostat hybrids. ML specs say 4ohms nominal, min 0.7ohm at 20KHz.
Regards
-steverw