I have nothing to offer on Carver tube products, but I do have an old M-200t poweramp whose duty has been just to run the midrange on the analog setup in my living room. It’s been hooked directly to a pair of Altec 511 horns w/Peavey drivers for the past 30 years. It is silent at idle, never pops on turnon or turnoff (both important with that load) and produces crystal clear sound. It won’t handle a capacitive load (goes into oscillation), but I don’t use one.
It is one of the famous or infamous ’magnetic field’ amps that tended to burn power supply resistors. I have a Carver receiver of somewhat later vintage that does just that if you don’t put a fan on top, but this one has never had a heating problem.