Problems with buzzing noise/interference

**Redwave** · 07-27-2012

I've got this strange buzzing/interference noise coming from both my headphones or speakers that I can amplify when I whack up the volume from my amplifier. I've noticed it also makes noises that occur whenever I do something on the pc, if it's opening a browser, playing a game or even just moving the mouse (oh what fancy noises they make!).

My setup is shown below.

I've tried replacing the cable going from my PC to the amplifier but this hasn't made a difference. I've also tried moving the sound card around, as well as connecting everything to the same power source. Nothing. The problem still remains.

I'm guessing it's most likely interference but is there any way to reduce/eliminate this?

Help please

**bandcoach** · 07-27-2012

Sounds like your power supply isn't up to providing power for your sound card; what ever your current powers supply is rated at, try to find one that has at least an additional 200 watts/VA rated power.

Ask more questions if you do not understand what is suggested....

**Redwave** · 07-27-2012

Why would the PSU be an issue? I sincerely doubt this, as I'm 99% sure it's a grounding issue. Although what is causing it, I have no idea.

**bandcoach** · 07-27-2012

I'm 100% certain that it is not a grounding issue.

It is a well settled fact that if a power supply tries to provide more current than it is rated to, there is noise and other power related hash generated on all of the power lines inside a computer.

See this thread for more details on the hows and whys. Ground Loop Problem

I am sure that foggy is more than happy to walk you through the issues in your machine as well.

btw, what is your computers power supply rated at??? (about 350w would be my guess - this is not large enough to do the job that it needs to do in audio production......)

**Redwave** · 07-27-2012

My PSU is a Corsair 520W. My average power usage is around 300 W (I've measured this using a electrical watt meter), this is why I doubt it's my PSU. I will double-check again just to be sure (as I did this before swapping out one component).

I admit I've had my PSU for a while now (5 years now) so it might be failing if what you say is true. However buying a new PSU is a last resort, as I would not be a happy bunny if I splurged on a power supply only to find out the issue hasn't disappeared.

There is one thing that points to what you are suggesting being true. This noise is not the typical 50/60 Hz "hum" heard by a lot of heavily amped audio systems; it's a high pitched buzzing noise that responds when I do something on the PC (move a mouse, browse, activate a program, etc). I should also point out that when I'm in the BIOS, no noise is heard (or at least it's very minimal, much MUCH less than when the windows screen shows).

**bandcoach** · 07-27-2012

It was the statements made about mouse and keyboard that confirmed for me that it was not a grounding issue - if it were; using either of these would not have any effect.

BTW, checking your power usage with a watt meter is not a good guide as to what is being used. This is because your PSU provides several different line voltages at different currents. it is the sum power used that you are measuring, rather than the individual lines - if your USB lines are pulling more than 5 watts then you will begin to hear noise and notice lagging on usb related activities.

If one of the 5v lines or the 12v lines is being stressed (being consistently pressed to provide more current than it can provide) then you will hear this hash in the audio lines. If several of the supply lines are being stressed, then it is all the more certain that you hear it as audio hash.

As you mention that it is high Freq noise, it is possible that some capacitors have blown in the PSU - it could still work, but would stress signs would be even more pronounced.

**Redwave** · 07-28-2012

Gotcha. I suppose you've convinced me enough, but one other possibility that a few people lay claim to, is that the card is picking up interference from within the PC and that simply buying an external sound card will remove this issue. What do you think?

**bandcoach** · 07-28-2012

Dubious, but as with anything, get your own local expert to have a look first, before spending big bucks.

On a side note, if it were the displays acting funny, or the system just seemed to sieze up for a moment and then continue, I would suggest getting a new video card, as this is the usual first sign of problems. I experienced this a month or so ago and replaced the video card which immediately fixed the problems.

I also had some issues with power in my "old" Dell gx620 tower. Replaced/bumped the power supply up to 520w from 300w and all of the issues related to power disappeared. I even have some free lines left over as result of this swap, so if something becomes an issue, I can provide separate rated power to internal devices as needed......

**Redwave** · 08-30-2012

I've had no issues with any other components whatsoever. Unfortunately I don't have any local experts in my area so I'll just have to get a new PSU. Fortunately the cost difference between my old one and a new one will not be too great.

---------- Post added 08-30-2012 at 01:58 PM ---------- Previous post was 07-29-2012 at 12:31 PM ----------

Hi guys, quick update. I decided to just connect the monitors directly to the sound card and keep the headphones connected to the amplifier. I should have checked that my card has two pairs of outputs, my fail here.

So now the buzz is not heard from the speakers at all, and is only heard through the headphones when I max out the amp volume.

Thanks everyone!