My 101 runs warm, not hot, and my 301 a bit warmer yet, even at idle. Neither gets nearly as toasty as my little Forte class A amp, but they're not as stone-cold as, say, the average SS preamp or Cd player.
Some amps run in class A mode up to a certain power level, then switch at higher power levels to class A/B. If an amp is in class A up to 30 or so watts -- the output devices are running at full power, the amp would give off a certain amount of heat continuously.