noise from other appliances

  • Thread starter Thread starter Skeleton Man
  • Start date Start date
Would one of those EMI filters from a switch mode psu work ?
(I have several dead power supplies which I could salvage one from)

If the AC input is PCB mounted I won't bother modifying it (too much work
for a minor problem), I'll just buy some kind of inline plug-in filter..
Click to expand...

First find where the noise is getting into the speaker amplifer.
Unplug the signal cable going to the computer, and if you still hear
pops and clicks, then it's the speaker amplifier's power supply
probably needs the filter. Otherwise the computer power supply is
more likely to need it. It's more likely that the amplifier needs the
filter because computer power supplies with no EMI filters on the AC
side will still block quite a bit of interference because all have EMI
filters on the DC side. You can tell if a supply has no EMI filter at
all because it'll create a great deal of interference on AM radio.
 
First find where the noise is getting into the speaker amplifer.
Unplug the signal cable going to the computer, and if you still hear
pops and clicks, then it's the speaker amplifier's power supply
probably needs the filter. Otherwise the computer power supply is
more likely to need it. It's more likely that the amplifier needs the
filter because computer power supplies with no EMI filters on the AC
side will still block quite a bit of interference because all have EMI
filters on the DC side. You can tell if a supply has no EMI filter at
all because it'll create a great deal of interference on AM radio.
Click to expand...

The noise is getting in via the amplifier.. my old speakers never had this
problem.. (power brick though, not inbuilt power)..
I run an old AT box for a server and the power supply has an EMI filter, but
it still interferes with AM radio... strange thing is the intereference
with the stereo right next to it is very low.. yet my clock radio up the
opposite end of the house picks it up badly..

You think it's worth pulling the EMI filter from a dead AT supply and
putting it in the amp ? (in series with AC in)

I don't plan on building a whole seperate box with a series of chokes, etc
just to stop small clicks in my speakers..


Regards,
Chris
 
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