PC to recevier casuing feedback

[jcesa00]

I recently purchased a pioneer elite receiver (VSX-43TX). I have hooked up my sound and video output from my pc to it. I am getting allot of feedback from my PC. I have tried other inputs...i pod, record player and no feedback. Do i need a special type of connection, wire, sound card....etc? I have a Ge force 7900 gto, and my sound is comming straight from my motherboard (Intel D975xbx). Any advice would be greatly appreciated.

Jason

[peterb]

Is it feedback or interference?

PC's are electricall;y very noisy and generate a lot of intereference. Much of that is screened out by the case, but it is possible for the interence to be picked up by the connecting cables. I assume that the interference (if that is what it is) only happens when the PC is connected to the amplifier. If you have a digital (optical) output on the PC and optical input (or SPDIF connections) then that is the best way to reduce the interference. Good quality cable with good screening on the analogue connections may help reduce intereference, but these problems can be hard to resolve.

[jimbouk]

If you have any old modem cables around with a ground loop isolator on then you try and add that to the audio cable.

[jcesa00]

I have 550watt power supply. Do you think it would change if I got a sound card vs. the on board audio. I have also heard about putting ferrite rings on the ends than plugging in to the input outputs.....??

[jcesa00]

By screening what to you mean??

[Thorsson]

No it wouldn't help to get a soundcard. My guess is that moving the receiver further away would help. It may be a cable issue, but I had a similar problem and I found that simply repositioning the offending item a couple of feet further away cured it.

[peterb]

By screening what to you mean??

Screened cable. (in the context that I used the word screening in the post above) Most audio cable is screened, but the quality varies.

[jcesa00]

I will try moving my PC away from the receiver and than re-post. As of know it is only about 1.5 feet away from it. Something strange I noticed as well is when I unplug my s-video cable going from video card to receiver I get lots and lots of feedback that is only corrected when I plug th cable back in.

One final thing.....talking about quality of wire. Are there specific indicators, names , numbers of better quality or am I to look at price only.

Thanks again

[jcesa00]

What does a ground loop isolator look like, and where on the wire is this to be added.

[jcesa00]

So than it could very well be the video cable...possibly it is not screened.

[peterb]

So than it could very well be the video cable...possibly it is not screened.

A|gain hard to say. If the interference is worse with the S video connector completely removed, then it points to poor screening on the audio cables - while I don't necessarily subscribe to the view that expensive = better, cheaper thin cables are less likely to perform as well as more expensive ones. You could try Maplins for suitable cables (Avoid PC World/Currys, they are generally overpriced)

If the interference is worse when the S Video lead is connected, then the screening on that is likely to be poor, but again improving the audio leads may also improve things.

As I say, this is very hit and miss - I can only point you at possible causes - you may buy a better cable and find that the problem still exists.

A ground isolator is usually a ferrite ring or bead that you feed the cable through (about three turns) or clamp to the cable. This acts as a choke and presents a high impedance to interefence being generated on the screen itself (Series mode interference)