Unequal shereo channel output ?

Suggest you provide more information such as, does the imbalance occur with all inputs? Have you switched left and right inputs between the pre and power amp? What have you tried so far?

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!