Unequal shereo channel output ?

Good question re: all the inputs? If all ARE involved- Find some interstation noise on the tuner, switch the MX to "MONO" and if the output is still uneven: switch the L & R inputs to the amp as Timrhu suggested. If the channel with the lower volume doesn't swap: You know it's the 2205. At least you can narrow it down that much.

Thanks for the good troubleshooting advice. Yes all inputs are involved. Switched the MX to mono & output remained uneven. Swithced L & R inputs and the volume did not swap, and the meters went dead to boot. I guess I will now switch out the 2205 with another amp and see what happens. I just need to devise a way to make my cabling more accessible to facilitate cable switching.

Given your 2205 contains some 45 transistors, 49 diodes/rectifiers and 8 integrated circuits: It would behoove you to find a qualified McIntosh service center, with the diagnostic equipment, documentation and familiarity to correctly repair the unit. Once you have convinced yourself that the amp is the problem that is. (http://mcintoshlabs.com/owners/mcintosh-service-network.asp)

Thank you Rodman. I guess I'll hook up my trusty old MC240 while the 2205 is in the shop. I use Analogique in New York City for my McIntosh service.
I guess one can assume that anything bought off of Ebay is going to require some service and $$$ sooner or later.

Any piece of gear that is still cranking out music after thirty-something years will require service and $$, regardless of where it was purchased. Hopefully- It'll last you another thirty, should you continue to enjoy it that long. Happy listening!