Strange sound problem, please help.

[HighFidelityGuy]

Hi,

I was recently setting up my AV amp after swapping round my speakers and so switched on the pink noise generator on the amp to check the levels of the speakers. I never bothered doing this before as I only used the amp for stereo up until now. When I switched the pink noise between the two front speakers I noticed that the tone and pitch slightly changed between L and R channels.

To try and track down the cause of the problem I generated a pink noise track on my PC that switches between the L and R channels every 15 seconds. As I use my PC as my Hi-Fi source, I then played this track through my amp.
I still got the same difference between the speakers, so I know the amps pink noise generator isn't broken.

I then plugged headphones into my DAC and still got the difference. I then tried the headphones directly on the soundcard on my PC and still got the difference.

So there is a difference in pitch and tone on pink noise all the way from the source to the speakers. So the problem should be with the PC, but I get the same problem when the noise is generated on the amp. So now I'm completely confused and think I might be going slightly mad. :mental:

I assumed that pink noise should sound the same between L and R channels as they are both the same speakers. I could understand if I was comparing completely different speakers but I'm not. My main speakers were also originally sold as matched pairs, so they should be identical.

Has anybody else encountered anything like this before, or does anybody know why this is happening?

Thanks.

[The Grand Wazoo]

Have you tried switching speaker cables? If the difference is in the same speaker then its the room. Just a thought.

[HighFidelityGuy]

Have you tried switching speaker cables? If the difference is in the same speaker then its the room. Just a thought.

I've not tried that yet as my speaker cables aren't terminated and I'm getting some new ones soon, so I couldn't be bothered to mess around with the cables.
I'm pretty sure it's not them to blame though as I also get the problem through headphones.

I may have a partial solution to this now though. I still can't explain why I hear a difference in the chain before the amp but I might know why the amp's pink noise generator sounds wrong. Basically I think my amp has just died. :(
Literally 5 minutes ago I was using the amps pink noise generator and the amp switched it's self off. Now I get a constant hum through the speakers.
I still get music too but also a hum. So I think part of it has died.

I'm going to try a couple of things but I think it's broken. Luckily it's still under warranty. :(

[HighFidelityGuy]

Ahhhrg, I've just switched the amp back on again and now the hum has gone. :confused:

What on earth is going on here? This is driving me mad. :steam:

[hifi_dave]

Seems like you've got a faulty amp. Perhaps it's your Guardian Angel telling you to give up on AV.:ner:

[Spod]

May be heating-up related. Leave the amp busy for an hour or two now and see if the hum returns or if the amp switches itself off again. I've had similar problems myself in the past with a basic amp, fortunately it was pretty new so I just got it replaced.

[HighFidelityGuy]

Lol Dave, the thought did cross my mind.

I don't think it's an overheating problem. I've only had the amp switched on for about an hour tonight playing music and TV and low levels. I've had it playing music louder for 9+ hours without any problems.

The amp switched off tonight exactly as the point when the pink noise should have started as though it has that feature that malfunctioned.

But it's working fine again now. :confused:

[Mike]

It's all due to spells cast by the AV witch! :uhho:


Burn it at the stake and switch to stereo!:lolsign:

[HighFidelityGuy]

Just a quick update on this problem:

After recently buying a pair of monoblock power amps I had the oppertunity to take my AV amp out of the equation. Unfortunately the problem with the L and R channels sound different with pink noise is still there. So my AV amp wasn't entirely to blame. So I think it's either my soundcard that's dodgy or it's just one of those odd problems that you never figure out.

However, on the subject of my AV amp, I've encountered the strange buzzing/hissing problem a couple more times so I took the amp back to the shop and Arcam are going to try and fix it.