Help with noise

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I recently bulit a chipamp (form Brian Bell) and the thing has absolutely surpassed my expectations of quality and power. The problem is with my soundcard. I get a buzz/hum only when using the PC as a source. No one else notices it, nor does it effect the enjoyment of listening. But, I know it's there and it bugs me. I have made all the standard ground loop test and subsituded sources and cables to come to the conclusion that the noise is generated from the soundcard it's self.

I downloaded a "freebe" analizer and found that with everything muted, the card is generating a 66hz signal at about .18 volts. This is a CHEAP built in soundcard but is the buzz a result of the switching power supply?

Would a quality soundcard help or would I still get the buzz because of the power supply? How bout a USB sound card with it's own separate PSU?

Thank you in advance for sharring in knowledge or experience.
 
Switching power supplies usually work in the range of 30-50kHz.
Normally , PC sound cards don't generate noise.Try plugging in headphones.If the problem persists , buy a new sound card.
I would't go for a USB sound card.Its quality may be questionable , especially if it is cheap.
 
This 66Hz signal is the vertical retrace of your monitor :)

It may be picked up in several ways, though. It may be coming either from your monitor or from your video card, so the first test to perform is to check whether the noise persists with the monitor turned off and/or with the VGA cable unplugged.

Tell us your findings.
 
Eva

Tried with monitor off and with video disco'd. Still got the hum. The video card has a fan on it. Could that be the cause?


Bazukas

Everything is muted.

The hum doesn't start until the sound card is activated.

The hum is not that prominate and wouldn't even bother me so much if the amp wasn't perfectly silent with no input or with a stand alone cd player. But, I built it for my PC.

Thanks for the suggestions. Any more would be greatly appreciated.
 
not driver problem. the noise happens right on boot. could be 66hz is measured by the software instead of 60 because of the steps of resolution in the software..maybe ther eis no 60 and 66 is the closest one.

it may be "good enough" by the motherboard designer and nothing you can do about it.
 
Well in my experiences with onboard sound, you can hear the mouse making sounds in your speakers when you move it, and you hear different sounds as the computer processes. My PC with a soundblaster 5.1 is fine, but my brother's PC with onboard sound, you can hear little noises when you move the mouse, and my computer did the same thing with onboard sound before I got my soundblaster.

Onboard sound is C R A P and picks up all the noise from signals generated in the motherboard, which gets sent to your amplified speakers. :smash:

Get a soundcard if you want to use your computer for playing with audio. :att'n:
 
OK folks. I borrowed a cheap PCI soundcard from a freind who admitted it was a crapy card but, I thought what the heck. I installed it and the hum was almost gone. But now I have a hiss! :)

But it proved to me that sound cards can really make a difference. Actually the hiss is less a problem with this card as it seems to put out about 20% more volume. Turning down the amp to achieve same level almost intirely eliminated any hiss. But, the guy was right. It's a crappy card. Noises and pops when Media Player starts and noise when adgusting volume on TV tuner card.

So.... I'll be looking for a GOOD, but cheap, soundcard for awhile.

Any suggestions?

Thanks to all for helping out!
 
Well. after listening further, (been busy) I had just as much hum on the PCI card as the onboard chip. It was masked by the hiss. I told ya it was a crapy card. :)

Did a lot of searching and phoning. Heard an example of a guy with an M-Audio card that for an un-related reason bought a better power supply. The result was hum!

A freind suggested and I tried this: Took my Son's MP3 player and hooked it up, with no battery, into the USB port . Used the earphone output to feed the GainClone. Result: NO HUM! Even at 100%!

I'm sold!

I'm going USB. Preferably one with it's own power supply! :)

Any suggestions?

Warnings?
 
noise

Hum is a common problem when interfaceing a sound card to a stereo or amp. You computer is grounded youre PCI card uses a uni-polar configuration, ground is tied to V-/ single ended PS. This cause voltage variances to be applied to the G / V- to the amp inturn Hummmmm, Lift the ground or isolate the input to the amp with a high quality transformer like a Jensen.
 
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