Cannot assume that power supply are automatically hot if the heatsink is hot.....
Bombaywalla (System | Reviews | Threads | Answers | This Thread)
There are plenty of resistors close enough to the coupling, and other caps inside the amp to soak up the heat from those resistors. A lot of the time when I buy something, I look inside and see the caps or resistors leaning toward each other on one side of the amp (one channel), and not the other channel. This is quite common, and on upper end gear, not just mid-fi. I've seen this in all kinds of electronics, more so with PC boards. A lot of heat inside some of them. That's why I said it depends on the design. I have some stuff with a lot of clearance that needs nothing in the way of extra cooling. When some people buy this type of gear, they'll say it's just a big box of nothing. Maybe the designers did this for heat and other beneficial reasons.