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Noise when Playing music from computer to amplifier

camerart

Active Member
Thread starter #1
Hi,
I have music on my computer, but when plugged into my stereo amplifier, I hear 'computer' noises, which spoil the music.
When nothing is playing, I can here the computer 'thinking', especially when using the mouse.
Can anyone offer a cure for this please?
Camerart.
 

Ian Rogers

User Extraordinaire
Forum Supporter
Most Helpful Member
#4
Hi N,
Ok, i'll look for one.
Why doesn't my two month old internal one work as inspected?
C.
The sound card isn't dedicated to one app... When you run windows media player you will have "other" sounds amplified..

Just as a tester... Download Winamp and try music via a different application.. It may be an application thing!!
 

alec_t

Well-Known Member
Most Helpful Member
#5
If you right-click the speaker symbol in the system tray you should get a pop-up with a 'volume mixer' listed. Make sure all other sound sources except the wanted one are muted or set to minimum level in the mixer.
 

camerart

Active Member
Thread starter #6
Hi I and A,
I generally use VLC, but have Winamp also.
even with no application running, there are noises.
I found that moving to AUX and adjusting the settings including switching off/down system noises in 'Volume mixer' I am able to get acceptable results although it isn't HIFI quiet, especially when you bear in mind, that it isn't Vinyl on a turntable:)
Thanks, C.
 

crutschow

Well-Known Member
Most Helpful Member
#7
What computer do you have?
My HP desktop internal sound card has absolutely no noise and it goes to a good amp that drives a pair of high quality speakers.
Sounds like maybe something's faulty with yours.
 

camerart

Active Member
Thread starter #8
What computer do you have?
My HP desktop internal sound card has absolutely no noise and it goes to a good amp that drives a pair of high quality speakers.
Sounds like maybe something's faulty with yours.
Hi C,
The computer was built for me using a sound chip on an MSI Pro H110i PRO mother board.
C.
 
Last edited:

dknguyen

Well-Known Member
#9
Are you plugging into the front jack or rear jack? I've never seen a computer where you can use the front jack because they pick up so much noise somehow.
 

dknguyen

Well-Known Member
#13
Hi D,
Sorry my mistake. My computer only has connections at the side, rear and the screen.
C.
Well, if it's happening in your rear jack too then there's not much you can do. Either changing your the soundcard, mobo, speakers, or cable lengths. Or go with an external amp. Just a bad combination of equipment.
 

unclejed613

Well-Known Member
#14
you might also try updating or reinstalling your audio driver software. also, try ferrite beads to isolate signals picked up on the audio cable.
 

camerart

Active Member
Thread starter #15
Hi,
The mystery unfolds!
I tried filling in the manufacturers tech support questionnaire, which took some time, with all of the details, clicked send and got 'site busy try later' and the form re-set:banghead:

A parcel arrived and my son said try this: An AV:LINK Ground loop isolator.
I connected the leads through it to the AMP phonos, and the noises have disappeared. Brilliant.
Then I tried removing it and still no noises.

What was the problem, and what changed?
C.
 

MikeMl

Well-Known Member
Most Helpful Member
#16
I was going to suggest a transformer ground-loop isolator in the audio path. We hams who connect audio to/from PC sound-cards to our transceivers found out twenty years ago that the chassis of the PC (the gnd side of the RCA jack) is hot with common-mode PC related garbage, including crap from the switching power supply in the PC. The ground-loop isolator effectively breaks the path for the common-mode noise that would otherwise travel along the shield of the audio cable.
 

camerart

Active Member
Thread starter #17
I was going to suggest a transformer ground-loop isolator in the audio path. We hams who connect audio to/from PC sound-cards to our transceivers found out twenty years ago that the chassis of the PC (the gnd side of the RCA jack) is hot with common-mode PC related garbage, including crap from the switching power supply in the PC. The ground-loop isolator effectively breaks the path for the common-mode noise that would otherwise travel along the shield of the audio cable.
Hi M,
That's fine, but can you give any explanation, as to why even with the GLI removed the noises are now not there?

Do you know what the difference is between a GLI and an isolating transformer?
C.
 

MikeMl

Well-Known Member
Most Helpful Member
#18
Hi M,
That's fine, but can you give any explanation, as to why even with the GLI removed the noises are now not there?
No clue.
Do you know what the difference is between a GLI and an isolating transformer?
C.
A GLI is a marketing term. Inside is a transformer with isolated windings. It takes two independent transformers to pass stereo.
 

camerart

Active Member
Thread starter #19
No clue.


A GLI is a marketing term. Inside is a transformer with isolated windings. It takes two independent transformers to pass stereo.
Hi M,
Previously, I had tried one track with an isolating transformer, but it didn't cure the noises.

The name GLI, includes the word ground, so I assume something has grounded coincidentally while I was playing around. Note, I had also tried a ground wire to the computer then to the amp, with no benefit.
C
 

MikeMl

Well-Known Member
Most Helpful Member
#20
Assuming that you have a stereo amp, you will need two isolation transformers. If you connect just one, there is still a DC Ohmic (Galvanic) connection between the chassis of the PC and the chassis of the audio amp. Isolation transformers work by breaking the Galvanic common-mode path, but letting audio pass through the magnetic flux in the transformer.

GLI=Ground Loop Isolator=Common-mode-path-breaker.
 

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