2. amps-preamps
  3. 1265762590

Intermittent hum in right Krell fpb 350 mono

Maybe you have experienced this but it is driving me crazy. Everything plays perfect, go to bed, next day, turn on the system and there is a loud hum in the right channel. Switch ICs in the back of the processor and the hum goes to the left channel. wiggle the plug on the amp, turn the amp on and off, wahlla! hum disappears and the system is perfect again. Occasionally that same right channel "fades" so I turn off the amp, wait a few seconds, turn it back on and it is at full strength.

I live in Mexico now so sending the amp in would probably cost more than the purchase price (if I ever got it back). Any thoughts?
puerto
sidssp
1,077 posts
 
Since the hum went to the left channel after you switched interconnect, the problem wasn't in your power amp, it was in your preamp/processor.
puerto OP
372 posts
 
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.
sidssp
1,077 posts
 
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.
thorman
1,262 posts
 
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
hifimaniac
508 posts
 
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.
More to discover