Does Pass Aleph 3 heat up the room like tube amp?

Yes, it is class "A" runs warm/hot. It's a nice amp. Sounds good after a half an hour... to an hour. So turn it off. No problem. (Mine sounded good with Audioquest Viper interconnects.) Good luck. Catagory: Probably shouldn't have sold it.

Thanks guys. Glad I asked. Look like I have to stay away from Plinius, Pass Labs & Clayton!

Any good cool running amps should I look at? I tried an Old Rotel amp from my HT system, it sounded really bad!

my experience has been that if you choose a system based on the heat that it makes (or doesn't), the sound will reflect that.

If the heat issue is really that bad, look into class D amps.

There are probably other alternatives though. You could vent the heat out of the room via the ceiling or a vent near the ceiling. Or you could use more efficient speakers and run a smaller amp.

My DNA-500 used to run pretty cool and I kept it on all the time. It would be worth auditioning.

Some of the amps on offer from the companies you mention offer a switch that lowers the bias and allows the amp to run a bit cooler when not in use or not being used for critical listening. Didn't know if you were aware of that or if it would make a difference, but just thought I'd mention it since I didn't see it mentioned above.