Pass Labs Amps - Does the heat bother you?

Like others have mentioned, the size and location of your listening room will make a huge difference.

I own the Aleph 2s, again. The first time was in Germany where my listening room was in the basement. The size was appx 15x17. I left them on 24/7 and never had any heat issues. Sold them because I liked the VTL's I had just slightly more. Regretted that move.

Fast forward 20 years and now the listening room is a small 13x14 room. I came to own the Aleph 2's again. In this small room it raised the temp by quite a bit, making it uncomfortable in the summer. 

The only way to solve the issue is to run the window AC while the amp is on and turn off the AC while listening. I also turn the amps on/off when not in use. 

I owned a Pass X350... it did not get beyond slightly warm even when driving at high volume. I left it on for ten years, before upgrading. 

I have the Pass Labs XA-25 that doesn’t really get hot maybe a tad over warm but my speakers take nothing to drive

+1 to this. Same results and situation 

When I had my pass x350.8 it was in my large basement and the added heat was very welcome. I could tell when I left the amp

on vs off and walked in the room. My open basement was always cool and the amp doubled as a 550-600watt (I looked at Pass Website- it’s more than 400w) space heater. Room would nominally be around 67F btw. I also owned XA30.5, 150.8,250.8, INT60. I ran the 250 and INT and 30.5 in my smaller office system upstairs and the INT60 and 250 made a noticeable increase in room temp with the office door closed. When the sun beats on the front of the house it was a sauna in the office with Pass gear. 
Now, it’s your system and your ears but I can’t believe you are considering pivoting away from a moon 861 amp for a 350. This is a pretty big step backwards. It’s a real sonic downgrade. If this is about the thin sound your are getting with you Focals by all means get new spekaers. It’s not the amp. If you do go ahead with a new amp will u continue to use a Yamaha integrated as a preamp? None of this makes much sense to me but as was stated previously it’s your $ and your system so knock yourself out! Have fun and keep us posted 

@howardlee lol. You aren’t wrong. Good times.