2. amps-preamps
  3. 1232637880

Hissing and Hum through speakers

Hi everyone,
I have a fair amount of hissing and small hum coming through my speakers...when music is played at mid to high volumes the hissing and distortion is very audible through the tweeters/speakers. I don't think it is distortion (not sure how I can tell) I think it is that noise that exists in the system and it gets exaggerated at higher volumes...

I have a Panamax unit where everything is plugged in and the Panamax and amplifier plug in to the same wall outlet.

The noise goes away when I mute my pre-amp (Meridian 561.) But with the pre-amp on and non-muted and any source selected the noise is present. Even when the source is in pause.

Also, I have unplugged the inputs from the pre to the amp (line level) and the noise is still present. Same for my center channel amp, and I also have a third amp with same results..

Does this indicate that the noise is coming from my AC line? I have done most of the troubleshooting (different cables, plugging and unplugging sources, et cetera) that I know and have not been able to resolve...
yanniz
yanniz OP
6 posts
 
thinking about for one more second, I doubt it...with nothing plugged in to the inputs of the amp, and just the speakers plugged in to the amp, I still get the same noise and hum...I will try it anyway..
sarcher30
596 posts
 
What speakers are you using and how sensitive are they?

If they are close to 100db then you may need a quieter amp.
yanniz OP
6 posts
 
they are the Jamo C809, 89db...6 ohms..

I plugged my ipod in directly to the amp just for the heck of it (headphone out so that I can adjust the volume,) and it seems like the slight hum that I had went way down, but the hissing sound from the tweeters is definetelly there...

Not sure it is the amp, I think it is AC line noise but wouldn't that be more in the form of a hum instead of hissing tweeter sound?

Thanks guys...
sarcher30
596 posts
 
The hum is probably a ground loop. I don't think the hiss is AC related.

You might try a different set of speakers to see if your still getting the hiss. Are the speakers new?

The reason the hum went down with the ipod is because it runs on a battery and isn't causing a ground loop. PS audio sells power cords that have a removable ground pin. Do a search on ground loops you'll find lots of info on them because they are a common problem.

You've eliminated the preamp and source as the problem so its got to be the amp or speakers. Since you've tried different amps that leaves the speakers.
sarcher30
596 posts
 
You might try plugging the whole system into another circuit to see if that changes anything.
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