A couple of simple questions

Hi folks, just a couple of quick (and more than likely stupid) questions.

Firstly for those of you with amps that use motorised volume pots i.e remote controlled do you hear the motor movement through your speakers if there is no audio signal? I ask because last night I was using my headphones as I didn't want to disurb the neighbours and I noticed that when there wasn't an audio signal and I changed the volume on my RA-02 via the remote I could clearly hear the elcetrical whine of the volume pot motor. Just to check I wasn't imagining it I tried the same thing through the speakers and got the same result, admitidley you have to be fairly close to the speakers to hear it. I'm just paranoid that my unit has developed a fault.

Secondly, while carrying out the above experiments I noticed that with no audio signal there was a low static hiss coming through the speakers. More noticeable with the headphones than the speakers. I assume that this is interference from the mains?

BL21DE3

 

I have a Denon midi in another room and you can clearly hear the motor sound you describe

 

dunno anything about remote controls, the hiss is always made by amps, I think its noise by the resistors, and circuit noise, and there isn't a lot you can do about it.

 

My Marantz PM7000 does the thing you describe with the motorised volume pot, it is rather quiet though...the noise through the speakers is far less obvious/annoying than the noise I can hear from the motor itself though.

As for static hiss through the speakers, well I can't hear any, its possibly drowned out by the computer but even so I can put my ear right next to either speaker and can't hear a thing (where as the motorized pot noise is discernible using the same listening method).

 

tip for amp users, turn the vol. up loud with no music on and put your lug next to the spx.

 

1) Just tried this and yes, the S300 does it as well. It's probably due to the EM emissions of the motor, which are picked up and demodulated by the amplifier circuitry.

2) The hiss is normal. It's thermal noise inherent to any resistor (or piece of wired, etc).

 

Cheers for the replies. It was just the usual thing, the minute you notice something odd/different then you worry and focus on it. To be honest I wasn't aware of either of these 'effects' until I had my headphones on last night and they don't impact on my listening pleasure. But I just wanted to make sure they weren't indicative of problems/faults, so thanks for the info.

BL21DE3