Carver363

Welcome Geoff! I believe both of those amps use individual speaker relays for the left and right channel outputs. I repaired my TFM-55 with relays from circuits and concept if you determine that's the root cause. Les is a great resource for high quality parts and a member of this forum. Good luck and post your progress!

you get this figured out?

The speaker wire is not in the hole for the black terminal. I would follow your red connection and retest. see image below.

Exactly on the relays! Circuits and Concepts has them in stock.

I have a TFM-24 in one of my rooms using RCA from preamp to amp. I used banana speaker output from amp to speakers. The amp terminals also allow for twisted wire connections. The amp is very strong for any bookshelf speaker as with most 8~4 ohm large speakers. It has been ultra reliable for me. Please attach pictures of your current setup and connections in the the back to better understand the question.