I had an all BAT outfit a while back. VK5 + VK500 w/BAT PK.
thankfully, it was in my office and not in my listening room. yep. the big BAT amp gets hot. very.
A lot of amps do however. Class D has made some immense strides and is a prospect for me with my next system build. I was disappointed to see Bel Canto quit making their top tier 500 wpc amps though.
Glass and Class A will always be heat sources. Period.
for my money, it is worth thinking abuot putting the power side of things, if not all of it, into a separate enclosure, or room and supplying it with cool AC.
whichever way, keep mindful of matching the impeadances between pre & amps, and in the wiring too.
be well, J