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Need HELP-Troubleshooting weird balance and hiss issue on Parasound 2100 preamplifier

Ok
Bear with me on this weird issue.  Last year I forgot to turn off my amp as I switched out my left speaker and  I crossed positive and negative wires. After the loud pop sound the only thing I could determine as far as damage seemed to be, as impossible as it sounds, on the preamp. Now every time I first turn on my preamp I would get a loud hiss that would slowly die out after 15 seconds. The left channel also seems to have a significant drop on output. ( It follows the channel as I can move it to the right speaker by swapping interconnects). Switching speakers -amps-cables ect...does nothing but show its from the preamp -I assume its output stage. Local service bench tested it out and could not replicate hiss. For the out of balance issue I can apply pressure downward on the balance knob and will even out the right and left channels. This is crazy but I actually have temporary piece of plastic shoved in to the slot to keep it even. Does any of this story sound familiar and does my temporary fix make any sense? Can 
azthu
213runnin
914 posts
 
Too bad about the accident, recently I removed speaker jacks after turning off the amp but still got a pop in the speaker, no damage though.

With the hiss issue it's apparent something is damaged, and the balance knob makes me think that pushing the shaft like that causes something losing contact within the pot.  

I'm tend to err on the side of caution when I can, so I'd suggest emailing Parasound asking to send in your 2100, maybe asking for an idea of cost.  They actually are quite good with emails and are quite willing to work on their products, or so I've read.
azthu OP
24 posts
 
I appreciate the help.
Of note I have had the factory tech guys at Parasound check it out and they didn't find anything out of sorts.  This tells me it is something very rare and weird. I wondering if the entire balance mechanism requires a change out. Maybe then the hiss will follow.
213runnin
914 posts
 
Wow that's a strange one.  If the tech guys at Parasound couldn't find out why the balance was off, then you really are out of luck.  I would have thought they'd suggest replacing the balance pot in that case.
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