Continuous buzz from speakers

[red-vex]

Hello all! Here's my prob:
I just upgraded my system and bought new case+psu (550W no-brand) for a new MoBo (asrock sata2-glan) + new CPU athlon 64 x2 5200 + Sapphire Ati x1950pro + Maxtor DiamondMax SATA HD 250 GB + 2GB ram but no need to get into configuration that much. I'm using my SB Audigy from previous system and a maxtor PATA hd of 200 GB, and my logitech 5.1 speaker system which has always done good w previous pc. Now I mounted all that stuff on my own and when i turned it on it all went smooth until i turned the speakers on and started hearing a buzz at 0 to low volume and at max volume. when the knob is around the middle it almost goes away, but i hope there's a way to wipe it out w/o having to become deaf. I bought a new APC plug but it did no good apart from letting me know i have no grounding in my wall plug. The buzz seems to be the amplification of my CPU fan and to test that i've opened my case and put a fan in front of it. As the temp went down so did the RPM of the Cpu fan (cool'n'quiet technology i suppose) and so did the pitch in the buzz. I also noticed when i switched the various speed of my fan it caused a crack in the speakers (like electric charges..dunno). Last thing I noticed is when i plug headphones in the on-speaker jack the sound is OK and clean. Hope you can help me, this is driving me crazy!

 

[red-vex]

Any ideas, anybody, anytime?

 

[old jc]

Hi Red sounds like interferance from your power supply. One of the downsides of less expensive ones is that they throw out a fair ammount of electromagnetic noise - interfeering with other electrical devices near by and mess up the smoothness of the mains power - interfeering with any devices connected to the same wall socket.

Try testing it by connecting the power supply of your speakers to an extension cable connected to a socket in another room. Then place the speakers as far from your pc as possible. The buzz should reduce and may even go away all together.

If this works try keeping the speakers where they are then connecting their power supply to the socket you had it connected to in the first place. Hopefully it should show whether is the proximity to the pc's psu or the socket your using that is causing the problem

 

[CCT]

Good article about connections:

http://www.epanorama.net/documents/pc/cdrom_audio_wire.html

In your case, particluar note should be made of:

"First thing to do do is to look at the soundcard itself. Usually the ground pins in the audio input are connected together in the soundcard and connected to the computer power supply ground which is permantly connected to computer case (you can use multimeter to check those ground connections if you have one). Be caseful not to cause electrostatic discharge damages to the soundcard and other components inside the computern when you look at the soundcard or make measurements on it."

If that grounding-to-case situation applies, and your comp isn't connected to a third prong grounded outlet, perhaps there is a distortion effect?

 

[red-vex]

In response to old jc: I tried to use another socket and move the speakers as far as i could, including the sub-woofer to which they are linked and which provides power, but to no avail. I noticed, however, messin around with the jacks, that if i unplug them from snd card and touch a metallic part of the case with them (speakers and pc powered on), I get the *same* buzz as when they're plugged in;
CCT: I didn't completely understand the grounding matter in the article you kindly provided, you know, my english ain't so good. Could you explain it to me yourself in an easier way? However the sound card is the same i've been using, with no problem, on the previous assembly.

 

[old jc]

Red it sounds like you need to earth your case. Though I've no idea how you manage that without an earth pin on your plug...

 

[Tedster]

you have either a poorly shielded speakers or PSU. Also they could be grounded poorly.

Your PSU is probably the culprit. El Cheapo PSUs are poorly grounded/shielded.

 

[red-vex]

you have either a poorly shielded speakers or PSU. Also they could be grounded poorly.

Your PSU is probably the culprit. El Cheapo PSUs are poorly grounded/shielded.

You're probably right. Guess I'm goin to have to change it, nothing else I can do about it right? El Cheapo's are affordable, and quality PSUs are slightly over my budget. Unless I just *have to* buy a new one, I'd rather try another solution, if there were.

 

[Skorponok]

Hi I'm new and having a similar problem, one which is also driving me mad. I would really appreciate some help.

I bought a Landsound 5.1 Home Theatre Surround Speaker (ebuyer . com:80/product/126902) for use with a pc with onboard sound which supports 7.1 (or 6.1 not sure). It is set up for 6channel however.

Now the system works perfectly with my mp3 player and laptop. But when I plug it in to my PC I get a buzzing through all connected speakers and from the sub itself. This happens on all pc connections (front, rear etc) and with 3 different cables so its not the cables/connections (I believe).
I have used a creative previous 5.1 system before on the onboard sound which works fine.

The strange thing is - when I shutdown the computer, turn off the PSU on the back and turn it off by the plug the buzzing still occurs!
And when I unplug the PC the buzz stops. I have also tried a different power cable.

So it can't be the PSU...right?

It has completely baffled me, can anyone please help? I'm considering sending the system back.

PS. I'm from England where we have 3 pronged plugs with an earth pin(?) (I know nothing about electricity). I've read this can have an effect on it?

Any help?

Ryan.

 

[duneworld]

Hello, I also have a buzzing sound coming from my speakers, not only when plugged into the sound card, but when pressed against the palm of my hand. I have a 2.1 system, which I have had for about 2 years now, (I bought them second hand), it started buzzing periodically about a year ago, but the problem could be solved by moving the jack around until now.
I have tried plugging them into another laptop and it still buzzed, but it was a slightly different sound/pitch (if that's important, which I doubt), I have yet to try out a good sound system to check if my soundcard is all right, but I'm pretty convinced that it is the speaker jack that is the problem. I'm wondering if there is a way to fix a faulty speaker jack, or whether (as I have seen suggested on another thread) it is cheaper, easier and more worthwhile to get a new speaker system entirely. And just to clarify, if there is a problem with the soundcard as well, I would have to get a PCMCIA card?
Thanks for any help.