Bryston B60 is an awesome machine

, it will play hotter at 4 ohms than at 8 ohms.
I had a B60, it runed some how a little hot at 6 ohms but the sound was wonderful.
if I had to change something about the B60, I would just change the small heat sinks for bigger and outside ones. I know it will be bigger and more expensive, but it will run cooler and that means....instead the 20 years warranty, you will have a 60 years warranty lol.
Bryston B60 is on top of my list of the best integrated amp under 100 watts RMS per channel period!!!