Electronic Interference On Speakers

Warlord_1011 · 25 Jul 2010 at 21:54

I have a Cambridge Audio DTT3500 and have used it on my PC with my B&W 601 S3 speakers for about 3 years, and I have a BIG PROBLEM

in weeks gone by i used to have a popping coming from the channels

Now it sounds like a AC sweep signal, it starts at a high frequency and it slowly decreases(It is a audible frequency variation) it goes down to only a few Hz and increases up to definitely a few thousand Hz.

It is not a sinewave, as it sounds like popping.

It is not the PC or speakers as i have disconnected all signal inputs into the amp and still it has the same issue.

CAN SOMEONE PLEASE HELP!!!!

Mason- · 25 Jul 2010 at 22:08

Is it a low hum, it sounds like Mains Hum, happens on my 5.1 speakers so I can't use them anymore. Basically the power supply bit (the large bit between the plug on the wall and the sub) has gone a bit, or your mains sockets are a bit weird.

Try it by plugging it into a single wall socket in a different room or something like that, that should tell you if it's the speakers or the sockets.

Feek · 25 Jul 2010 at 22:18

Mains hum would be constant at 50Hz, it's not that. I don't know what it is, but it's not mains hum.

mistercrabb · 25 Jul 2010 at 22:22

AC/DC converter thing on the blink?

I have a lamp upstairs that makes a buzzing sound that changes tone when you hit it. I'm not sure why.

Warlord_1011 · 25 Jul 2010 at 23:44

It is sweeping in frequency, i dont have a oscilloscope to test it, but my multimeter isnt picking up any oscillations on the DC output.

BloodyL · 25 Jul 2010 at 23:57

Could it be interference from one of those homeplug mains networking kits?

Dogoid · 26 Jul 2010 at 00:09

they're here

Warlord_1011 · 26 Jul 2010 at 10:26

It is only my amp what does it and it only does it for about an hour or so, so unless it was a capacitor what blocked the signal once it has warmed up...?

wonko · 27 Jul 2010 at 07:47

When it does it for an hour or so, is it a sudden start and stop, or does it fade in and out? I'm presuming that this is a background noise, and that the amp works otherwise?
Maybe the amp is susceptible to radio frequency interference (picked up via signal and mains leads)? Does it still do it with only mains lead and speakers connected, and if so does it change if you move the amp and leads around?
Alternatively, your neighbour is an alien overlord who is transmitting invasion plans home.

BloodyL · 27 Jul 2010 at 11:07

Either that or he lives next door to the dolphinarium at his local zoo!

Stickman · 27 Jul 2010 at 12:16

Maybe try adding some ferrite rings? In the past I've found them cheap and effective in similar situations.