| mashaffer |
I had a 20x20 car amp hooked up to a 12V PS on my bench runing into two cheap speakers and the high level inputs of an AR 8" home subwoofer. It played fine for two and a half hours. I shut it down and moved it around tp make things more neat and now I get hum regardless of whether there is any input and there is also almost no output from one channel. I can reduce the hum somewhat by rearranging the componants but I haven't been able to eliminate it or get the other channel back.
Then it hit me to check the resistance between the speaker grounds so I disconnected the amp and measured across the negative sides of the speaker wires (this includes the wires, speakers and subwoofer inputs). I got 112 ohms. Would that be close enough to a common ground to blow the amp after a couple of hours? Did I likely blow the chip on one side?
If this is the problem is there any way to get around the problem and still use the subwoofer in this setup? |
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| mashaffer |
| It was indeed an interaction with the subwoofer inputs but I didn't fry the amp. I tapped into the preamp level inputs to the amp and ran those to the low level subwoofer inputs and all is well. |
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