I gotta think there's a bit of overkill going on here.

I agree that stacking a bunch of amps is not a good idea if it does not allow any one of them to cool properly - and heat's a potential killer of electronics - over extended periods at high temperatures.

However the mechanics (actual heat transfer / fluid dynamics) regarding a stack of components (alike or otherwise) is not a simple back-of-the-envelope (or off-the-top-of-the-head) calculation. Without some proper experimenting / modelling, I doubt that anyone could say, for sure, that channels stacked in a certain way will be inherently better than another, insofar as assuring that critical components are properly cooled. For example putting the hotter-running components on the bottom of the stack just might induce a higher mass flow rate of air through the stack, leading to an overall better net cooling effect. But then again it might not.

Likewise, you cannot know for sure that arranging channels on a multi-channel amp in a certain way will also have a better net cooling effect.

And even if you did know the answers - how would it actually translate into longer component life?

Perhaps one way of tackling the problem would be to ask service shops about which channels in a certain multi-channel amp fail the most frequently, and try to relate that back to your initial guesstimates. I assume that the majority of users actually hook up their amps as labelled - or if not labelled, without thought as to loading.

Besides, if I were designing a multi-channel amp, and labelling its channels, I'd design the heat sinking , and cooling fan / flow, to take into account channel loading - if it were an issue. Wouldn't you?

Jeff Mackwood