Intermittent hum in right Krell fpb 350 mono

Sidssp I was thinking that since the "right" IC was now in the Left input of the processor that the amp in question was now driving the left channel.

No, since you switched the interconnect, the right channel of your preamp is now driving the left channel of your power amp. If the problem were in the power amp, no matter how you switched the interconnect, the hum should still stay on the right side. So the hum was either caused by the interconnect or by the preamp.

I am guessing you have a bad connection in one Interconnect,,I had them same issue and there was an internal break in the wire on one I/C..Wiggle the wire and it makes a connection ( for awhile ) and then eventually will not work..If you can temporarily change I/Cs and Power cords etc..this could be your problem ..Good luck

I had a hum in a mono amp once and determined it was something as simple as the power cord and an interconnect touching and running together in a parallel line. Once I separated them the hum went away. Check all your cords and be sure they aren't touching in a parallel fashion; cross them at a 90 degree angle. I hope it is as simple as this.

Sidssp you are correct - I had to think it through! Interesting though that by (sometimes) wiggling the power cord plug on the amp that I can stop the hum. Other times, when switching the ICs the hum shows up in the opposite channel but is greatly diminished. Also, I can sometimes amplify or diminish the hum by disconnecting the TV cable,

Thorman: I did substitute other IC cables to no avail but a good thought.

Hifimaniac: I just rearranged all of my cables, cords, etc. A couple of days ago but will double check for that. I thought it was fixed when I removed a "silent" exhaust fan that was close to the I/C input of the processor but after several days of perfect performance the hum just showed up again. AGGGHHH!

Thanks to each of you, I will continue the quest.