My Singlepower ES-1 Amp (with HE-90) crackles only in one channel with or without source and it is intermittent. Actually it comes and goes for days at a time and is very hard to duplicate on demand. If I unplug the power supply for a day it will usually behave for a few days.
I know nothing about electronics. I had a local tube amp wizard go through the amp and all was OK and he could not duplicate the problem. He did not however go into the power supply.
Should I try a power conditioner? It is just plugged into the wall and there are lots of other things on the circuit. If so, what is recommended?