Well, I think the TFM-45 is a more elegant design (mag field, etc.) The A-760X is a brute force design (lots of parallel output devices). It is a "standard" amp by Carver standards (simple transformer unregulated power supply). The A-series amps have no T-mod, so they weren't voiced to any specific amp. I think the TFM-45 was voiced to Carver Silver-7 tube amps.
My personal preference would be dependent on where yo plan to use the amp. If it were for bass reinforcement, I'd go with the A-760x. For ribbons or e-stats, I'd go with the TFM-45.
It should sound like it isn't there!
There is a difference between hearing and listening...
Making life enjoyable through expensive electronics.
Carver: C-4000 & C-1 preamps, PSC-60 preamp/tuner, TX-11a tuner, M-400 (2), C-500, M-500, M-500t, M-500t Mk.II, A-500x, AL-III loudspeakers (2 pr.)
Sunfire:Theater Grand III processor, Ultimate Receiver, Cinema Grand Signature 400 ~ seven, True Subwoofer Mk. II, D-10 Subwoofer