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Ground Loop and pitched sound

tsine

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Hi to anyone .

I have a D50S connected to my desktop computer via usb and to my speaker via rca (focal alpha evo active speakers) .

The problem is I have a lot of noise coming from the pc .
Most of it was ground loop so I tried my luck with usb isolator ( ifi one from a friend ) .

Ifi defender solved the noises coming from moving the mouse or GPU working and most of the harsh sounds(I guess ground loop noises).
But introduced a very high pitched and very noticeable "ZZZZZZ" that is so pronounced and I can hear it through songs .
If I remove IFI isolator the buzz and hum comes back but the high pitched "ZZZZ" goes away.

The IFI isolator is not faulty because in my friends setup it works very well without any issues.
Also d50s is not the fault because If I connect the d50s to a work laptop or my phone through usb I don't any noise as all .

The computer and dac power supply come from the same power strip (because i read most of the thread in here )

Any cheap solution that will work so I can use my desktop computer for listening to music ?
 

tonycollinet

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This will all be ground loop. (Either the DAC, or the Speakers (or both) must have a grounded power supply)

Best way to solve will be to isolate the computer from the dac by connecting them using TOSlink. (Optical). Alternatively if you get a balanced DAC (or an active RCA to balanced TRS converter, and go to your speakers with a balanced connection that should help a lot (but not as good as the toslink - unless the loop is between dac and speakers.
 
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tsine

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This will all be ground loop. (Either the DAC, or the Speakers (or both) must have a grounded power supply)

Best way to solve will be to isolate the computer from the dac by connecting them using TOSlink. (Optical). Alternatively if you get a balanced DAC (or an active RCA to balanced TRS converter, and go to your speakers with a balanced connection that should help a lot (but not as good as the toslink - unless the loop is between dac and speakers.
Do xlr balanced cables eliminate all the noises coming from the computer ?

So technically I have to buy rca-> xlr active box ? Is this going to eliminate the noises ? Any company suggestion

I use wireworld stream line rca cables with a good shield on them.

Toslink is not an option and also i tried decupling with ifi isoloator the computer and the
 
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tonycollinet

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Why is Toslink not an option. Worst case, you could get an inexpensive USB to Toslink output.

Or plug in a sound card with Toslink to your PC - or depending on your motherboard, you might already have an SPDIF interface on it that just needs a cheap optical connector adapter card like this

XLR / Balanced will eliminate noise between your DAC and your speakers. Common mode rejection is typically 40 to 50dB, so noise should be reduced by this ammount - but not cut out completely as Toslink will.

Shield on the RCA is not the issue - it cannot solve a ground loop problem.


EDIT - I've just looked, and your D50S has bluetooth input. Assuming your PC has bluetooth, you could try using this to connect to the DAC - even if only a test to see if breaking the electrical connection between DAC and PC will eliminate the noise.
 
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tsine

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Why is Toslink not an option. Worst case, you could get an inexpensive USB to Toslink output.

Or plug in a sound card with Toslink to your PC - or depending on your motherboard, you might already have an SPDIF interface on it that just needs a cheap optical connector adapter card like this

XLR / Balanced will eliminate noise between your DAC and your speakers. Common mode rejection is typically 40 to 50dB, so noise should be reduced by this ammount - but not cut out completely as Toslink will.

Shield on the RCA is not the issue - it cannot solve a ground loop problem.


EDIT - I've just looked, and your D50S has bluetooth input. Assuming your PC has bluetooth, you could try using this to connect to the DAC - even if only a test to see if breaking the electrical connection between DAC and PC will eliminate the noise.
Is there a limitation to optical compared to usb ?

It's very strange that a DAC measuring good is so prone to USB noise from a desktop computer ....
 

tonycollinet

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Is there a limitation to optical compared to usb ?

It's very strange that a DAC measuring good is so prone to USB noise from a desktop computer ....
It's not usb noise - it's ground noise. And it is not the dac that is prone to it. It doesn't matter what the dac is - if your system set up creates a ground loop - yours does - it is just a huge loop antenna which will pick up any stray magnetic field going, and PC's are great generators of stray magnetic fields - especially high power graphics cards. The only link to USB is that USB is not an isolated connection - so it forms part of the loop. Combine that with an unbalanced RCA connection where the signal is carried on the same ground (the shield) and you have a recipe for problems.

It also tends to be an issue with powered speakers, because often the speakers are not located close the source/dac, so the power cabling for the speakers makes the loop much larger. It's one of the reasons that more often than not they have balanced connections available.

Regarding your question about tos link - depending on the kit you might not get as high a sampling rate as on USB. However, it is high enough for you to be unable to hear the difference - and certainly infinitely better than a noisy ground.

Have you tried a bluetooth connection as a test?
 
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tsine

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I have tried to use Bluetooth and I had no issues with noise.
Also if I connect the USB cable to my phone and play music over USB via my phone I don't have noise either.

Only for my desktop computer when I plug the USB I have noise.

Also I tried the optical from my for my TV box and also no noise there.

The only time I have noise is when I plug in my desk computer.

I have to mention that also I tested with my laptop and my laptop has no noise in the speakers even when it's charging.
 

audiofooled

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You could try different settings in your BIOS regarding spread spectrum and see if it reduces EMI without compromising system stability...
 
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tsine

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You could try different settings in your BIOS regarding spread spectrum and see if it reduces EMI without compromising system stability...
Spread spectrum affects noise ?
Maybe if I underclock bellow stock setting it will help with noise ?
Also does a better power supply like a good seasonic titanium efficiency reduce these annoying sounds ? (But I guess if I have to buy a 200$ pay it's better to get a balanced DAC ...I don't know I guess )
 

audiofooled

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Underclocking may help in some cases but I wouldn't expect much. I'm just saying you could try free options first and see if it improves the situation. My desktop is dead silent when it comes to this but it's Ryzen 5 without dedicated GPU (Vega graphics). Power supply is nothing special, really, as well as mobo (B450M). Maybe it's because of the illuminated audio noise guard on it and advertised high end audio components, just kidding.
 

Chrise36

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Spread spectrum affects noise ?
Maybe if I underclock bellow stock setting it will help with noise ?
Also does a better power supply like a good seasonic titanium efficiency reduce these annoying sounds ? (But I guess if I have to buy a 200$ pay it's better to get a balanced DAC ...I don't know I guess )
Just buy the spdif converter there will be no downgrade in sound quality.
 
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tsine

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Just buy the spdif converter there will be no downgrade in sound quality.
I can't find one here in Greece spdif board .

The only think similar to optical is buying internal sound card pci express with optical out . Cost is around 50€
 

Chrise36

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I can't find one here in Greece spdif board .

The only think similar to optical is buying internal sound card pci express with optical out . Cost is around 50€
If you dont want the one from uk there are similar from amazon de for less than 30 euro
 
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tsine

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The option are buying an internal sound card pci express with optical out
Asus xonar se for 39 euro

Or buying a new motherboard with build in optical out
around 120 euro

Or finding an spdif board that i cant find any store around Greece
 

Chrise36

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Fiber is 100% going to work i cant know if this filter will
 

tonycollinet

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I have tried to use Bluetooth and I had no issues with noise.
Also if I connect the USB cable to my phone and play music over USB via my phone I don't have noise either.

Only for my desktop computer when I plug the USB I have noise.

Also I tried the optical from my for my TV box and also no noise there.

The only time I have noise is when I plug in my desk computer.

I have to mention that also I tested with my laptop and my laptop has no noise in the speakers even when it's charging.
That is because your phone has no connection to ground. On the plus side this pretty much eliminates any ground loop between your DAC and your speakers.

By far your best solution is going to be toslink to your DAC - though I very much doubt you'll hear a difference between your USB connection and an APTX bluetooth one - except for the noise being eliminated.

What motherboard do you have?
 
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