I recently added a power amp to my system and am having some problems with it. I used to be running a Denon AVR 988 amplifying 5 speakers in a 5.1 configuration. Now I've added a Carver M-1.5 power amp to power front L and R in the setup. I have the Carver connected to the switched outlet on the back of the Denon (since it has no power switch), and the front L and R pre-outs on the Denon connected to the Carver. Now, when the Denon is on and nothing is playing, I hear a pop or hiss from the speakers every few seconds. It sounds fine when there is audio playing, but it is quite noisy when nothing is playing. At one point, when the system was idle yesterday the popping got worse and worse, until the circuit breaker popped. Is this a grounding issue? What can I do to rectify this? (Note: The power amp's plug has no grounding pin)
Noise and Circuit Breaker Issue from Power Amp
- Thread starter moolcool
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whoaru99
Epic Member
First thing I would do is move the cord of the amp to a different power source, not on the receiver.
While I do not know the specifics of these exact units, often is the case the receiver auxiliary receptacles are not intended for supplying large amplifier power.
Also, if it is tripping the AC mains breaker in normal use, it's possible the amp is defective and the noise+breaker tripping is the early symptom of a pending bigger failure.
Also, after moving the power connection, another test would be to disconnect the signal cables to the Carver amp (but leave speakers connected to it) then see if the noise follows just the amplifier.
While I do not know the specifics of these exact units, often is the case the receiver auxiliary receptacles are not intended for supplying large amplifier power.
Also, if it is tripping the AC mains breaker in normal use, it's possible the amp is defective and the noise+breaker tripping is the early symptom of a pending bigger failure.
Also, after moving the power connection, another test would be to disconnect the signal cables to the Carver amp (but leave speakers connected to it) then see if the noise follows just the amplifier.
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Thanks for the reply! I tried what you suggested.
First I unplugged the receiver from the Carver, and plugged it into it's own outlet (everything else in the system turned off/unplugged). That is to say, the system consisted only of the Carver, and the two speakers. I still got the noise problem. I could also feel a static buzz when my hand was behind the unit. Is this the Carver starting to die, or could it be something more simple? (I think I read something about tightening screws on older amps with grounding issues)
First I unplugged the receiver from the Carver, and plugged it into it's own outlet (everything else in the system turned off/unplugged). That is to say, the system consisted only of the Carver, and the two speakers. I still got the noise problem. I could also feel a static buzz when my hand was behind the unit. Is this the Carver starting to die, or could it be something more simple? (I think I read something about tightening screws on older amps with grounding issues)
whoaru99
Epic Member
If the problem occurs with only the Carver amp and connected speakers then, yes, I think the problem is in the amp itself.
To me this does not sound like an external/safety grounding issue. I'm not familiar enough with the Carver amp to know if there could be a simple issue internally to resolve it.
If it was mine, I would remove the cover and see if there was anything obvious like component discolored/burnt, capacitor leaking/bulging, etc. Just don't get shocked poking around inside.
To me this does not sound like an external/safety grounding issue. I'm not familiar enough with the Carver amp to know if there could be a simple issue internally to resolve it.
If it was mine, I would remove the cover and see if there was anything obvious like component discolored/burnt, capacitor leaking/bulging, etc. Just don't get shocked poking around inside.