F**ked up problem with Epox Mboard - advice needed

[IdahoB]

Heya guys - got an interesting one for you.

I use a Terratec DMX6Fire soundcard for music production, and since upgrading my motherboard and case, the thing hasn't worked properly. Since then I've changed my case and motherboard again (although the case is a similar one and the motherboard is identical to the last).

Problem didn't go away, and I've been tearing my hair out and making Terratec tech support scurry around for weeks trying to fix it. Today I finally I decided to rip everything out of my case and see what happens. Well, with my system sitting in pieces on my desk the card works flawlessly.

It's obviously some sort of electrical issue (particularly since the fault is to add masses of distortion to any audio signal) but is there any way you can suggest for me to fix this without replacing the case?

Yours,
Andy Bellenie
www.dotspf.com

 

[IdahoB]

^ bumpity ^

 

[Bovinicus]

Perhaps the problem lies in your power supply, or even the placement of the case in your room. Perhaps there are certain spots in your computer room where EMI can buildup higher than other areas. Try moving the computer to a totally different room of your house, a different floor is possible. Even better, try hooking up your computer at a friend's house and see if that alleviates your problem.

Are you overclocking?

 

[IdahoB]

I think I was perhaps unclear. It's not a little bit of distortion, as though there was line noise caused by interference - I'm talking total distruction of the audio stream - the original sound being almost impossible to recognise, and several ports giving nothing but electrical noise. It's ugly.

I'm going to try sticking it back in the case with a layer of cardboard underneath the board. Get back to you in 20 mins.

 

[IdahoB]

Okay, now I'm really puzzled. Before trying the cardboard isolator I just decided to elimate my power supply as the fault, as suggested. Using my test bed PSU (cheap and nasty free job that came with a case) the system works fine. Using my proper PSU (flash Antec jobby) the fault re-appears.

How the hell can a PSU affect a soundcard?

 

[IdahoB]

Yep - I've rebuilt the whole machine now, and with the exception of the PSU nothing is different, yet it works perfectly.

There must be some clever bod out there who has a notion of how a PSU can cause that kind of problem. Was it sending too much power to a particular line? Who knows.

 

[Bovinicus]

I could understand why a PSU might cause problems with the soundcard, but I don't understand why the cheapo one worked better than an Antec PSU. Perhaps there is something wrong with that PSU. Perhaps it emits some different frequency EMI that causes problems with that sound card. It's really hard to say. If you got it working, then be happy. =)

 

[IdahoB]

Normally I'd agree, except the reason I have the Antec PSU in the first place is because it's virtually silent, something pretty desirable in an audio PC. F**king thing. I mailed Antec tech support but they for reasons best known to themselves decided to ignore it.

 

[redhatlinux]

I would guess that maybe the switching frequency on the Antec supply is different from the 'El Cheapo'. I have to believe that the actual voltages to the mobo are stable and don't have this kind of interference so the 'noise' must be 'radiated' from the supply. Kinda sucks but your choices are, different PSU or possible different sound card.

 

[IdahoB]

I'd be happy to go for a different soundcard, but nothing out there really compares to the DMX6Fire. If it did, I would have ditched it long ago.