I've owned several DNA-2's. My current amp is a DNA-2 Revision A version and I notice this once or twice 'popping' sound typically after I have turned off the amp (during cool down). I think it has to do with the heat sinks expanding and shrinking as you suggest.
But if you are still concerned, you might contact Steve McCormack at smcaudio.com.
-IMO
But if you are still concerned, you might contact Steve McCormack at smcaudio.com.
-IMO