• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Ground loop issues from computer audio

B

Bouly

Member
Joined
Oct 22, 2021
Messages
32
Likes
7
Hello, I am looking for advice on how to solve ground loop issues on my home computer setup. The main thing is that I want to be able to quickly switch between a desktop computer and a laptop for the audio source. Here is a schematic of the setup :

Capture d’écran 2021-10-22 à 11.34.53.png

I am considering replacing the power strip with a filtered one such as https://www.av-connection.com/?PGr=13568 .
Would that be a solution?
I thought plugging all components in the same power strip would solve ground loop issues, but I still have the ground loop.
Thanks for any insight.
 
R

raindance

Major Contributor
Joined
Sep 25, 2019
Messages
1,045
Likes
972
What's the symptom of your ground loop, ie what are you hearing?

Have you tried a cheater plug on the active speakers?
 
P

ppataki

Major Contributor
Joined
Aug 7, 2019
Messages
1,249
Likes
1,416
Location
Budapest
If you lift the ground of your PC that will solve the issue but it is somewhat hazardous so generally it is not advisable...
I have done that in the past when I had a miniDSP DAC8 and it worked like a charm

A more acceptable solution could be to use an isolation transformer on your mains: https://www.radioparts.com.au/produ...ectrostatic-screen-mains-electrostatic-screen
I am using one of those now and there is no more noise and the audio quality also got better since the isolation transformer provides galvanic isolation from your mains (=mains noise will not get through due to the lack of metallic connection)
 
OP
B

Bouly

Member
Joined
Oct 22, 2021
Messages
32
Likes
7
raindance said:
What's the symptom of your ground loop, ie what are you hearing?

Have you tried a cheater plug on the active speakers?
Click to expand...
Buzzing when moving the mouse. Noise whenever the computer is processing something.
 
OP
B

Bouly

Member
Joined
Oct 22, 2021
Messages
32
Likes
7
pma

pma

Major Contributor
Joined
Feb 23, 2019
Messages
4,608
Likes
10,779
Location
Prague
Bouly said:
Hello, I am looking for advice on how to solve ground loop issues on my home computer setup. The main thing is that I want to be able to quickly switch between a desktop computer and a laptop for the audio source. Here is a schematic of the setup :

View attachment 160689
I am considering replacing the power strip with a filtered one such as https://www.av-connection.com/?PGr=13568 .
Would that be a solution?
I thought plugging all components in the same power strip would solve ground loop issues, but I still have the ground loop.
Thanks for any insight.
Click to expand...

Same strip is no help. Put an isolation transformer before the PC, as I draw in the picture.

loopin system.png


isol_tr.JPG


I use
BREVE TUFVASSONS
PFS250/230/230V

www.welectron.com

Breve-Tufvassons PFS250/230/230V Trenntransformator 230V, 250VA, 99,0

Portabler Sicherheits- und Trenntransformator mit Schuko-Stecker und Steckdose, 230 VAC, IP44, Schutzklasse II, zur galvanischen Potentialtrennung
www.welectron.com www.welectron.com
or if 250VA is not enough, go to higher VA rating.
 
pma

pma

Major Contributor
Joined
Feb 23, 2019
Messages
4,608
Likes
10,779
Location
Prague
Bouly said:
Ok so I just made some tests. The issue seems to be coming from the external GPU. When I plug it out of the MacBook the ground loop disappears.
Click to expand...

Then put the isolation transformer before the MacBook. It may help or it will help before the PC, somewhere the loop is to be interrupted.
 
pma

pma

Major Contributor
Joined
Feb 23, 2019
Messages
4,608
Likes
10,779
Location
Prague
JayGilb said:
A good quality audio isolation transformer between your passive source switch and the powered speakers would probably be the easiest fix.
Low quality audio isolation transformer tend to roll off lower frequencies.

Jensen makes quality transformers. Link: Line Level Isolation Transformer
Click to expand...

They are more expensive than the mains line isolation transformer and they degrade audio signal, especially at low frequencies. I am leaving the thread, there will be no help.
 
OP
B

Bouly

Member
Joined
Oct 22, 2021
Messages
32
Likes
7
raindance said:
That is not a ground loop. It's interference and it's probably the laptop power supply.
Click to expand...
How would you solve interference then ? what's the difference with the ground loop ? I thought ground loop was causing interference
 
R

raindance

Major Contributor
Joined
Sep 25, 2019
Messages
1,045
Likes
972
Bouly said:
How would you solve interference then ? what's the difference with the ground loop ? I thought ground loop was causing interference
Click to expand...
Optical isolation works, balanced connections works, also sometimes using a different power supply helps. There's a lot of trial and error in figuring this out. But a ground loop is typically a constant hum.
 
OP
B

Bouly

Member
Joined
Oct 22, 2021
Messages
32
Likes
7
Alright so I have ordered 2 items :
- a high end ground separator : http://www.jenving.com/products/view/ags-10k-audio-4xrca-1021000045 . I would place it right after the audio source selector.
- a smart power filter : https://ifi-audio.com/products/gnd-defender/ . I would place it before the desktop computer or before the external GPU power supply.
When these items arrive, I will test them, and report if they fixed the issue. I picked these because I can install them with minimal changes to my current setup. If I still have the issue I will switch to an external DAC that can have 2 USB sources (to connect it to both the laptop and desktop) and has XLR output.
 
ZolaIII

ZolaIII

Major Contributor
Joined
Jul 28, 2019
Messages
4,195
Likes
2,475
Bouly said:
Ok so I just made some tests. The issue seems to be coming from the external GPU. When I plug it out of the MacBook the ground loop disappears.
Click to expand...
How much does it drowe, did you try to put it on another wall plug?

Edit: I know Asus can be itchy.
 
J

JayGilb

Major Contributor
Joined
Jul 22, 2021
Messages
1,384
Likes
2,355
Location
West-Central Wisconsin
Bouly said:
Alright so I have ordered 2 items :
- a high end ground separator : http://www.jenving.com/products/view/ags-10k-audio-4xrca-1021000045 . I would place it right after the audio source selector.
- a smart power filter : https://ifi-audio.com/products/gnd-defender/ . I would place it before the desktop computer or before the external GPU power supply.
When these items arrive, I will test them, and report if they fixed the issue. I picked these because I can install them with minimal changes to my current setup. If I still have the issue I will switch to an external DAC that can have 2 USB sources (to connect it to both the laptop and desktop) and has XLR output.
Click to expand...
That audio isolation transformer is interesting in that the L and R outputs are mirrored from the inputs. Something to watch out for when connecting. The technical specs are incomplete; it has a frequency range of 10-22k, but no +-db specs are given.

Good luck and I hope all is fixed when these devices are installed. I wouldn't worry too much about low frequency loss when using this isolation transformer.



ags-10k_600_v2.jpg
 
Last edited:
Berwhale

Berwhale

Major Contributor
Forum Donor
Joined
Aug 29, 2019
Messages
3,962
Likes
4,964
Location
UK
You must log in or register to reply here.

Similar threads

T
Looking for help diagnosing buzz/hum/ground loop in my "HIFI" GUITAR rig!
Replies
12
Views
664
DVDdoug
DVDdoug
L
High-pitched speaker noise from ground loop?
Replies
17
Views
1K
MaxwellsEq
MaxwellsEq
inuyama
The Return of Ground Loop
Replies
11
Views
881
inuyama
inuyama
M
Deafening hum from new DAC
2
Replies
24
Views
2K
miv
M
Larudakote
My first multichannel "ground loop less" DIY amplifier !
Replies
0
Views
548
Larudakote
Larudakote
Top Bottom