Question RE: Hissing audio over SPDIF (coax)

[karm100fists]

I built my PC and I have really enjoyed it's capabilities until recently.

I recently acquired a Pioneer VSX-1020-K AVR and Jamo S406 5.0 set of speakers. Previously I could enjoy music from my PC because I had poor quality speakers and could not detect the interference (or whatever it is).

Now with the new gear I can hear a hissing sound in the background of all music and movies coming from the PC (Coaxial - SPDIF). This hissing sound is not present when I play the same media over the network from my PS3 (through HDMI).

Here is my system
Processor: Q6600 2.4 GHz
Mobo: ASUS P5Q Pro
GFX: Sapphire HD4850 512MB @ (750 and 950 mhz)
RAM: G.Skill 4GB (2 x 2GB) DDR2 1066 (Stock @ 5-5-5-15)
PSU: CORSAIR CMPSU-750TX 750W
HDD: 2 X Western Digital Caviar Blue 640GB

What is the best path to resolving this problem? I already tried using a shielded cable. There is no optical out from my computer. I have come up with a couple of options, and need help deciding which is the most likely to resolve the issue for the smallest investment of capital.

1) New video card either HD5770 or HD5850 for audio over HDMI. This will cost at least $150.
2) New sound card. (What sound card should I get?)
3) ??? Suggestions ???

Any help would be appreciated.

 

[markw]

Sounds like the hiss/noise is being generated within the PC itself. Cabling won't cure that.

You might want to try a different sound card.

 

[karm100fists]

Any suggestions on cheap cards that have excellent audio quality, reliability, and compatibility?

 

[s162216]

Check your motherboards southbridge temperature, distorting or crackles in audio can be one of the first symptoms of the southbridge overheating. Basically feel it with your finger, if it feels red hot then try adding some more cooling to the PC or even better add a small heatsink to the southbridge as well.

I learn't this the hard way earlier this year: my audio started to get a low sounding hum/distortion if you listened carefully. I narrowed it down to the PC as disconecting the coax to the reciever made it disapear, but changing the cable did not. It was awful as when in a film for instance there was the sound of traffic there would be this terrible amplified distortion that I never used to get. It got worst though, the memory controller started randomly failing and the computer would just restart at the drop of a hat. Then I get after a restart: "IDE Controller Failure". The motherboard never worked again. Apparently the problem is quite common on Nforce2 motherboards like the ASUS A7N8X-E Deluxe I was using, old but nothing beats the onboard Nvidia Soundstorm with on the fly Dolby Digital Live encoding.
With my new motherboard I am going all out on cooling to prevent a similar occurrence.

 

[karm100fists]

Cool, a free solution to try!

I will look into that when I have some time, thanks!

 

[karm100fists]

Hmmm...

The problem seems to be greatly reduced when I set the default output of the audio device to 24 bits and 192000kHz.

It is even further reduced when I apply the "Pop" EQ in the RealTek HD Audio Manager.

I think that the issue may be my mp3s : /. Some of them just have noise at the high end because they were poorly encoded.

I may have to buy some music.

 

[s162216]

Theres an easy way to find out if thats the problem, when files such as MP3's are put over SPDIF their encoded as PCM so that the receiver can understand them, but it only does it for certain audio which is why games by default don't play over it generally.
CD's are PCM audio anyway so play one of them and if you still get the hissing then its not your music.

Did you check your southbridge temperature like I suggested?

 

[karm100fists]

NO! I forgot to, thank you. I will do that. I have no time for tinkering when I am actually in front of the computer sadly . Maybe tonight I will get a minute.

 

[karm100fists]

This is the motherboard with the old HSF. It looks like the southbridge already has a heatsink built onto it.

In case you wanted to know, here is the Motherboard now

 

[karm100fists]

Also,

it seems that there are two different kinds of distortion that I can hear. One is a hissing sound that begins when a track starts playing (during silence it is pronounced)

The other occurs when there is audio activity coming through the tweeter. It sounds like someone is putting white noise through a phaser.