@jfrmusic Pass amps operate at about 104-105 degrees Fahrenheit. I own X260.8 monoblocks (previously owned X250.5, XA30.8).
Love these amps with my Wilson Sabrina. However, Pass amps have a warm and natural sound signature. I would not recommend making an assumption Pass and your Harbeth will be a synergistic combination - Harbeths are very warm sounding speakers. If you can go back to Overture and have them set up the same model speakers with Pass for you, it would be best to spend some time listening.
If you like the sound, the X250.8 will most likely be all you need but it’s up to you if you want to go up to X350.8. I’m pretty sure that amp will never exit out of Class A with your speakers. Have a listen though.
Bryston 7B3 vs 4B3: Extra Cost Worthwhile?
Now that my dealer said he can deliver and unbox my amp the weight issue has been resolved. I don’t expect to be moving them as this is my end game system. At my age end game has real meaning. So I decided on Bryston and the 4B3. But then I got to thinking maybe I should go all out and get the 7B3 mono blocks. They are twice the price of the 4B3. For that additional expense I would hope and expect that once I heard them I would not be able to go back to the 4B3. However if the difference in perceived SQ is better but marginal the extra cost would not be worthwhile. I’m not looking for the ability to play loud but am looking for speaker control, dynamics, soundstage, etc., improvements that are clearly and unequivocally heard. So has anyone been done this road with these amps? If so please share your experiences