I have been using an older Carver TFM-22 amp to drive my M 60's I started to notice a "rattle" from the left (tweeter) speaker- especially audible while playing female choral selections. I removed the amp and wired it directly into my Denon 1909. Problem solved. My question is what is likely wrong with the amp and would it be an easy fix? The Denon does a fine job and I'm not likely to use the amp again, but I would like to sell it if this is a minor issue. Thanks for any advice.