I have just purchased a Marantz PM 94 amp. I'm aware these run hot and have noticed that the right heat sink (behind the vol pot) emits significantly less heat than the left heat sink, almost to the point of saying that the right hand side of the amp (looking face on) is only luke-warm to touch, not hot like the left side. Is this normal operation for this amp? If not, what may be casuing this to happen and suggested remedies? Many thanks.
The amp probably isn't symmetrical in layout. One side probably has the power supply and the other the output devices. Most amps do not have the left channel tansistors on one side and the right channel outputs on the other. It is far easier and much more efficient to design all circuits to run in particular areas of the chassis. If you'd like, just remove the top cover plate (with the amp unplugged from the AC outlet) and check where the output transistors sit. That's the side that will get warmer than the power supply side.
Just as a word of advice; not all "heat sinks" do anything. More than one fin on an amplifier has been placed there by the marketing department rather than the design team. Kind of like '58 Cadillacs.