Faint buzz from speakers connected to Rotel 1582 MKII

[anarchist]

Getting faint buzz from speakers connected to the power amplifier even when no input connected, likely 60 Hz AC noise. Can only be heard putting my ear right close to the tweeter.
Same speakers connected to my Denon AVR show no signs of such buzz even with volume at reference level.
Could it be bad a capacitor issue?

 

[DVDdoug]

Could it be bad a capacitor issue?

It's possible. Or it could be normal for that particular amplifier. All analog electronics generate SOME noise.

Or if you have a light dimmer, sometimes they'll put noise on the power line that doesn't get filtered-out through the power supply. Or maybe some other unusual noise on the power line.

Can only be heard putting my ear right close to the tweeter.

Try to forget you ever tried that.

 

[Nopiano]

Connecting an input may mute any noise. Have you tried that?

 

[anarchist]

Connecting an input may mute any noise. Have you tried that?

Yep, makes no difference with cables in, XLR or RCA.

 

[anarchist]

It's possible. Or it could be normal for that particular amplifier. All analog electronics generate SOME noise.

Or if you have a light dimmer, sometimes they'll put noise on the power line that doesn't get filtered-out through the power supply. Or maybe some other unusual noise on the power line.


Try to forget you ever tried that.

I'm more concerned if it's a failing cap then it will eventually fail at the wrong moment. Besides for $2K I just want the amp to match noise signature of my Denon AVR, at least. the Denon plugged into same outlet BTW.

 

[GD Fan]

My system uses a 1582 purchased new in Sept. of 2019. Putting my ear right up to the tweeters, a completely unnatural act likely never to be repeated, revealed a very minimal, faint hum from the speakers. I'd say it was unnoticeable from 1-3 inches away.

Presumably yours is more pronounced than that. My amp doesn't get pushed hard at all. Frankly it lives squarely in the realm of unnecessary overkill.

 

[Nopiano]

Yep, makes no difference with cables in, XLR or RCA.

This will sound pedantic, but is there a source connected to the cables? Otherwise and open socket or a cable is a bit like an antenna for noise.

 

[MaxwellsEq]

Yep, makes no difference with cables in, XLR or RCA.

In order to confirm it's something inside the Rotel, you need to short-circuit the inputs. This can easily be done with an RCA plug where the centre connector is soldered to the outer ring. You have to do this because an unplugged-in connection is an antenna.

 

[anarchist]

My system uses a 1582 purchased new in Sept. of 2019. Putting my ear right up to the tweeters, a completely unnatural act likely never to be repeated, revealed a very minimal, faint hum from the speakers. I'd say it was unnoticeable from 1-3 inches away.

Presumably yours is more pronounced than that. My amp doesn't get pushed hard at all. Frankly it lives squarely in the realm of unnecessary overkill.

Hum, like white noise is normal for any amp, especially when at reference level or higher with no input signal. What I hear is a 60 Hz buzz, that's what usually gets filtered by capacitors, not supposed to be there in any decent electronics.

 

[jonfitch]

It's always some heavy duty power amp that I end up getting some weird noise issues with. Not sure if it's because they are lower volume, and so less data available compared to mass market AVRs for reliability issues, or they are more susceptible to shipping or moving damage affecting performance.