Pioneer VSX-502 receiver - can hear radio faintly when in CD or TV mode

[OldReceiver]

I have a Pioneer VSX-502 audio/video stereo receiver purchased in
1993. It has developed a problem - when in CD or TV mode, i.e., not in
Tuner mode, one can hear some sort of radio faintly in the background.
When the volume is moderately high, it becomes very annoying - such as
while listening to soft passages of music or speech in non-tuner mode,
when one can hear what sounds like the radio coming through.

What is this "cross-talk" problem called?

Is there a fix for it, or do I need to replace it with a new receiver?

Thanks for all suggestions.

[Serge Auckland]

OldReceiver wrote:
> I have a Pioneer VSX-502 audio/video stereo receiver purchased in
> 1993. It has developed a problem - when in CD or TV mode, i.e., not in
> Tuner mode, one can hear some sort of radio faintly in the background.
> When the volume is moderately high, it becomes very annoying - such as
> while listening to soft passages of music or speech in non-tuner mode,
> when one can hear what sounds like the radio coming through.
>
> What is this "cross-talk" problem called?
>
> Is there a fix for it, or do I need to replace it with a new receiver?
>
> Thanks for all suggestions.

If the "radio" you are hearing is whatever the tuner section is tuned
to, then this is indeed crosstalk inside the receiver. As you say it has
just recently started doing it, it is difficult at long-range to
diagnose what could have caused it. I would suspect an earthing problem,
possibly an earthing tag has come loose, or has some corrosion around it.

If the "radio" you are hearing is not what the tuner is tuned to, then
it is most likely being picked up externally. The chances are that it is
a jumble of signals, making it very difficult to pick one individual
signal out of the mess. Most likely caused by again some grounding
problem or the something changing internally causing RF instability in
the amplifiers. In many amplifier designs there are small capacitors
used for stabilisation. If one of those has failed, or has a dry
soldered joint, it could cause what you describe. I once had an
amplifier that did what you describe, I finally found the amplifier had
an HF oscillation that beat with the RF normally picked up on
loudspeaker cables and produced the low-level but irritating noise.

As you say it varies with volume level, I would therefore look to the
pre-amp section first.

Good luck, this sort of fault is the very devil to fix.

S.
--
http://audiopages.googlepages.com

[Richard Crowley]

"OldReceiver" wrote ...
>I have a Pioneer VSX-502 audio/video stereo receiver purchased in
> 1993. It has developed a problem - when in CD or TV mode, i.e., not in
> Tuner mode, one can hear some sort of radio faintly in the background.
> When the volume is moderately high, it becomes very annoying - such as
> while listening to soft passages of music or speech in non-tuner mode,
> when one can hear what sounds like the radio coming through.
>
> What is this "cross-talk" problem called?

Can you hear the signal well enough to identify it?

Is it the same radio station that you would hear if the
switch was selecting the tuner? If so, then it is more
likely to be an audio crosstalk problem within the receiver.

OTOH, if it is some other radio station, then you may
be experiencing RFI (interference from radio waves).
Do you live near a broadcasting tower farm? Do you
hear this radio station in any other audio equipment?

> Is there a fix for it, or do I need to replace it with a new receiver?

There is likely a fix for it, but you have to properly identify
what kind of problem it is, first. Then it would depend if the
expense of the fix exceeds the value of the equipment.

[OldReceiver]

Thank you both for your helpful responses. Here's a bit more info.

The noise seems to be more than one radio station, and not clear
enough to identify one particular station, so it would seem to be RFI.
No, I do not live near a broadcasting tower farm, nor do I hear it in
any other audio equipment.

Also, it seems to be audible only when CD is chosen, not TV (sorry for
the incorrect info). This occurs whether a CD is actually being played
or not, e.g., when no signal at all is incoming through the CD inputs.
It sounds like a mass of distant radio stations al jumbled together.

And here is another important clue (just discovered): the cables (left
and right) going into the CD inputs are from the "out" of my
computer's sound card (Audigy ZX) (a stereo out that is then split
into a "Y" that goes into the two cables that in turn go into the back
of my Pioneer receiver). When the cables are removed from the
Pioneer's CD input the RFI goes away.

So it would seem that the receiver itself may not be to blame.

However, I'd still like to clear up this problem, because I use my
Dell WinXP Media Center computer to store and play mp3's and video
programs (TV, AVI's, etc.), and the RFI is annoying when playing
mp3's, etc.

What might be the source and a solution?


On Thu, 3 May 2007 06:55:09 -0700, "Richard Crowley"
> wrote:

>"OldReceiver" wrote ...
>>I have a Pioneer VSX-502 audio/video stereo receiver purchased in
>> 1993. It has developed a problem - when in CD or TV mode, i.e., not in
>> Tuner mode, one can hear some sort of radio faintly in the background.
>> When the volume is moderately high, it becomes very annoying - such as
>> while listening to soft passages of music or speech in non-tuner mode,
>> when one can hear what sounds like the radio coming through.
>>
>> What is this "cross-talk" problem called?
>
>Can you hear the signal well enough to identify it?
>
>Is it the same radio station that you would hear if the
>switch was selecting the tuner? If so, then it is more
>likely to be an audio crosstalk problem within the receiver.
>
>OTOH, if it is some other radio station, then you may
>be experiencing RFI (interference from radio waves).
>Do you live near a broadcasting tower farm? Do you
>hear this radio station in any other audio equipment?
>
>> Is there a fix for it, or do I need to replace it with a new receiver?
>
>There is likely a fix for it, but you have to properly identify
>what kind of problem it is, first. Then it would depend if the
>expense of the fix exceeds the value of the equipment.

[No Name]

OldReceiver > wrote:
>
>[....]
>And here is another important clue (just discovered): the cables (left
>and right) going into the CD inputs are from the "out" of my
>computer's sound card (Audigy ZX) (a stereo out that is then split
>into a "Y" that goes into the two cables that in turn go into the back
>of my Pioneer receiver). When the cables are removed from the
>Pioneer's CD input the RFI goes away.

It might be something as simple as a lousy cable letting RF leak into
your system. I'll bet this is the first time you've used this cable on
this receiver. First you want to see whether the computer is at fault
(doubtful), so try plugging the cable into an iPod or something similar
to see whether the problem follows the computer. Next try a different
cable and plug in a CD player into the CD player ins, to see whether
the receiver input is implicated.


Francois.

[Richard Crowley]

"OldReceiver" wrote ...
> Thank you both for your helpful responses. Here's a bit more info.
> The noise seems to be more than one radio station, and not clear
> enough to identify one particular station, so it would seem to be RFI.
> No, I do not live near a broadcasting tower farm, nor do I hear it in
> any other audio equipment.
>
> Also, it seems to be audible only when CD is chosen, not TV (sorry for
> the incorrect info). This occurs whether a CD is actually being played
> or not, e.g., when no signal at all is incoming through the CD inputs.
> It sounds like a mass of distant radio stations al jumbled together.

Then it is definitely RFI, not audio crosstalk.

> And here is another important clue (just discovered): the cables (left
> and right) going into the CD inputs are from the "out" of my
> computer's sound card (Audigy ZX) (a stereo out that is then split
> into a "Y" that goes into the two cables that in turn go into the back
> of my Pioneer receiver).

Sorry. I read that through five times slowly and I still don't
understand how you have that hooked up? Wanna try that
again? If cables go directly from your computer out to your
Pioneer receiver "CD in", what is the reason for the "Y-adapters"?
Are you trying to run BOTH the computer AND the CD player
into the same input on the receiver?

> When the cables are removed from the
> Pioneer's CD input the RFI goes away.

So use the standard technique of unplugging everything
and then replace it one piece at a time until the RFI re-
appears. Try without the Y-adapters, and then WITH
them, etc. etc. Try wiggling the cables/connectors. Try
using different cables and/or adapters, etc.

[Mark D. Zacharias]

OldReceiver wrote:
> Thank you both for your helpful responses. Here's a bit more info.
>
> The noise seems to be more than one radio station, and not clear
> enough to identify one particular station, so it would seem to be RFI.
> No, I do not live near a broadcasting tower farm, nor do I hear it in
> any other audio equipment.
>
> Also, it seems to be audible only when CD is chosen, not TV (sorry for
> the incorrect info). This occurs whether a CD is actually being played
> or not, e.g., when no signal at all is incoming through the CD inputs.
> It sounds like a mass of distant radio stations al jumbled together.
>
> And here is another important clue (just discovered): the cables (left
> and right) going into the CD inputs are from the "out" of my
> computer's sound card (Audigy ZX) (a stereo out that is then split
> into a "Y" that goes into the two cables that in turn go into the back
> of my Pioneer receiver). When the cables are removed from the
> Pioneer's CD input the RFI goes away.
>
> So it would seem that the receiver itself may not be to blame.
>
> However, I'd still like to clear up this problem, because I use my
> Dell WinXP Media Center computer to store and play mp3's and video
> programs (TV, AVI's, etc.), and the RFI is annoying when playing
> mp3's, etc.
>
> What might be the source and a solution?
>
>
> On Thu, 3 May 2007 06:55:09 -0700, "Richard Crowley"
> > wrote:
>
>> "OldReceiver" wrote ...
>>> I have a Pioneer VSX-502 audio/video stereo receiver purchased in
>>> 1993. It has developed a problem - when in CD or TV mode, i.e., not
>>> in Tuner mode, one can hear some sort of radio faintly in the
>>> background. When the volume is moderately high, it becomes very
>>> annoying - such as while listening to soft passages of music or
>>> speech in non-tuner mode, when one can hear what sounds like the
>>> radio coming through.
>>>
>>> What is this "cross-talk" problem called?
>>
>> Can you hear the signal well enough to identify it?
>>
>> Is it the same radio station that you would hear if the
>> switch was selecting the tuner? If so, then it is more
>> likely to be an audio crosstalk problem within the receiver.
>>
>> OTOH, if it is some other radio station, then you may
>> be experiencing RFI (interference from radio waves).
>> Do you live near a broadcasting tower farm? Do you
>> hear this radio station in any other audio equipment?
>>
>>> Is there a fix for it, or do I need to replace it with a new
>>> receiver?
>>
>> There is likely a fix for it, but you have to properly identify
>> what kind of problem it is, first. Then it would depend if the
>> expense of the fix exceeds the value of the equipment.

If the receiver is over about 2 years old the power supply could be noisy
and this could account for your problem.

If the sound card has a digital output available, try that instead, going to
one of the digital inputs on the receiver. Some sound cards have a
"multi-use" output even if they don't have a dedicated optical or coaxial
digital output.

Mark Z.