Advice needed on low volume and hum out of amp.


I just purchased a demo c-j MF-5600, multichannel amp online, and after connecting it to my Denon receiver, which I am using as pre/pro. The sound I am getting is at low levels, even when I turn the volume up noticeably. I previously had my front left and right speakers connected to two small monoblocks (Marantz MA-500's), which are rated about the same as the c-j (125 wpc), and never had this problem. I also get a hum out of the speakers. I assumed this was a ground loop that I couldn't isolate, but when I put one of the monoblocks on top of the c-j and reconnected the speaker to it, leaving all the cables and everything else in place, the sound level went back up and the hum disappeared. All components are routed through a power line conditioner. I am currently trying to work this out with just the front right and left channels only. I know this is not alot to work with, but maybe someone has had similar problems. Any thoughts would be greatly appreciated.
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Showing 1 response by aball

Perhaps the CJ amp inverts the phase? This may be a long shot but I know that some of the CJ preamps invert the phase and so this amp may also. I don't know what a wired-backwards amp sounds like so I can't say for sure. I don't know either if you would damage anything by swapping them to see or not. Perhaps others know. Good luck. Arthur