what's wrong with my amp?

[mentok340]

I just bought an old pioneer GM-X722 2 channel amp off ebay. When I hooked it up the right channel did not work. To bridge the amp you use the + from the left channel and the - from the the right channel. This worked. Is my right channel blown? I plan to use the amp bridged to a SVC 4ohm sub. It will work, but will I be getting full power or just the power from the right channel?

Click to read more...

 

[Spooney 10+ year member]

Was this amp listed as being in working order? If so you need to get in contact with the seller and tell him of the issue. Anyways on a troubleshotting note did you verify that your rca's were actually getting a signal to both channels of the amp? If you swap the left and the right inputs does the problem swap from one channel to the other? If you have a multimeter run a sine wave through the amp (doesn't really matter what frequency unless your crossover is engaged) and check the ac voltage on the working channel and on the bridged terminals. If the amp is doing roughly double the ac voltage on the bridged terminals as it is on the one good channel you are probably ok to run it bridged. I am curious as to why the right channel isn't working though. Most of the time when a channel or more specifically the output transistors are blown the amp will blow it fuses when remote turn on power is applied. Your amp isn't doing that so it makes me think it is an rca input or preamp related issue. Could be a broken lead on one of the rca inputs on the amp. Swap the rca's and see if the problem is still there.

 

[mentok340]

The amp was listed as working. Seller said he tried it on a type r dvc 12" and it worked. Whether he wired it bridged or stereo I don't know. I did switch the rca's when I tested it, and the results were the same. When testing it I hooked each channel up to one side of a comp set. Tried left, then right, then bridged. Got sound any way I hooked it up that didn't use the + terminal from the right channel.