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Help - Adcom GFA-545 works in mono only

I just got my Adcom GFA- 545 amp from eBay, that's I'm using to power NS-10Ms for a studio solution and I noticed that the amp works in mono only, regardless of source panning.

Both RCA inputs are ok, I tried plugging only one and panning worked as expected - no sound when panned hard one side, normal sound when panned to the other, so there appears to be mono summing going on inside the amp.

The other thing I've noticed is that the right side of the amp runs significantly warmer than the left, which is barely emitting any heat.

Do you have any suggestions as to how to resolve this?
Thanks!
jacentys
polk432
1,142 posts
 
Jacentys, that's good of the seller. Leave a positive feedback, since he cares about what he sells. Good luck.
wolf_garcia
6,625 posts
 
The last 2 audiogon items I attempted to buy were confirmed purchases followed by, "Oh...sorry man...I sold that last week"...and this has never happened elsewhere. I did have a couple of other successful a'gon purchases though. Ya never know...
kirkus
502 posts
 
there appears to be mono summing going on inside the amp.
Is it possible you have this amp switched into a "bridged mono" mode?
jacentys OP
3 posts
 
I was looking in the manual and there is no mention of such switch.

If that is the case, then I'm guessing there was some manual rewiring going on but I'm not good enough with electronics to troubleshoot that.
somec59
245 posts
 
Too much reflection on the current state of affairs... see prior post
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