Speakers hum while pc is off????

[Sweeper]

Just picked up a set of Boston Accoustic Micro Media speakers. Ok, on the Sub-woofer/power supply there is an indicator light which is green when on and amber when off. When I shut the pc down ( I have had tried these speakers on both my systems here) and the light switches to amber (standby) The speakers will develop a hum like power being surged thru them? I had them tested at where I bought them and they never found or heard anything. They told me to pick up some sort of inline AC convertor to keep the noise from appearing? Speakers bad or is it my house? I have a similer set of Boston Accoustic BA635 which work just fine. Not sure what to do?

[This message has been edited by Sweeper (edited 03-01-2000).]

[Serge]

Not sure if this'll help but in one location I had a suppressed noise from local car services and such (overloaded phone frequencies) coming over the speakers.. but it was a problem with phone lines in that location.

[wyvrn]

Had my speakers plugged into same room as my flourescent room light and they hummed constantly and popped when I turned the light off. Also check to make sure your speakers are not on the same circuit as major appliances like the fridge. AC filters can be found at Radio Shack and Wal-mart.

[youngqd]

Just possibly, might be, that amp has a floating input. A computer or any other input device shuts off and doesn't provide 'volume control'. If you were inclined you could put a 100k ohm resister between the input positive connector and ground connector. Should not hurt volume when 'input' device is powered on but will kill noise when amp is 'floating'. Try it with clip on jumpers to see before attacking your amp with a soldering iron.

[Ygor]

If you do what Youngqd suggests, don't overlook that K after the 100. That's 100,000 ohms, not 100.

[Axel]

What I've done with my home system is - my power supply has an output on it - I run a small power strip off of that which then feeds the monitor and the powered speakers and printer - I turn the computer off - everything else is off as well. Also - many computer power supplys have noise filters within them for just such issues. Coming out of the power supply to power your other devices means a nice clean source throughout the system.

[Ygor]

That sounds interesting Axel! What brand of power supply is it?
I've shopped Pricewatch for power supplies, never noticed that listed before... Obviously that's a switched output that goes on & off with the computer p/s.

[kwai]

axel, is that an atx power supply?

i remember seeing a lot of those ouput connectors on older at systems, but never on an atx ps. i wish they'd make a comeback.

[Axel]

Naw - it's a cheap chinese AT power supply I bought about 3 years ago along with a case. Nothing special except it has a 3 prong female outlet beside the 3 prong input.

Never had a problem with it, though. Definitely like the switched output.