SummerTime and Amp Heat

see if you can find out what at temperature the specific B&K model is supposed to run - if possible. Then make sure that you are operating it under those specified conditions.
For ex, many of Pass' designs (specifically the older Thresholds) were meant to have their heatsinks at 52-54C. That was supposed to be normal operating conditions.
FWIW.

05-30-11: Hifihvn
The links are to long to post. Just Google capacitor life shortened by heat.

True Hifihvn that cap life is shortened very quickly by excessive heat BUT.............just because the heatsink is getting hot does *not* mean that the power supply caps are getting hot! Depends how the amp is made & where the power supply caps are w.r.t. the power transistors & heatsinks. The OP says that he's drawing heat out of the amp which presumably means heat from the power transistors only. The power supply caps could be very cool if the amp has grates on the top-plate, bottom-plate.
Cannot assume that power supply are automatically hot if the heatsink is hot.....

I agree with Bombaywalla. Heatsinks get hot because they are doing what they were intended to do.

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.

No one seems to have mentioned the associated load on the amp and its output stage[s]. As a corollary, one sometimes sees ads that say "drove my Thiels/Apogees/'stats with aplomb". That's all good and well but it would seem that driving the amp to its upper limits might shorten its useful life and perhaps wear it out faster than one would with an easier load. Just wondering...