Ground Loop / USB output noise

[PointyFox]

It's not a ground loop. Isolators won't work. Filters won't work. Balanced won't work.
There is noise getting into the data path inside the motherboard.

Since you don't have an optical connection, you can either use Bluetooth or get an INTERNAL sound card. Don't get anything that connects via USB, it's already contaminated due to poor motherboard design.

 

[audio2design]

It's not a ground loop. Isolators won't work. Filters won't work. Balanced won't work.
There is noise getting into the data path inside the motherboard.

Since you don't have an optical connection, you can either use Bluetooth or get an INTERNAL sound card. Don't get anything that connects via USB, it's already contaminated due to poor motherboard design.

What exactly do you define as a data path?

The noise is from the description purely analog in nature.

 

[PointyFox]

What exactly do you define as a data path?

The noise is from the description purely analog in nature.

PCI bus most likely. Wires meant for digital signal can transport analog at the same time.

 

[audio2design]

PCI bus most likely. Wires meant for digital signal can transport analog at the same time.

Are you claiming bit errors or otherwise? You are not making sense yet.

 

[PointyFox]

Are you claiming bit errors or otherwise? You are not making sense yet.

EMI

 

[audio2design]

EMI

Can't say much evidence to support that. Generally ground loops which include high frequency noise and power supply pumping from load transitions.

 

[AnalogSteph]

Hifiman 4XXs
Honestly wanted to have headroom to try out different, inefficient planars down the line so I wanted to buy an amp that had a fair bit of power to run them without a problem.

A Magni Heresy / IEMagni is no slouch. It only has 0.6 dB less gain and about 2 dB less maximum output than the Asgard 3 (50 ohm load)... unless you were right on the edge to begin with, that's going to be irrelevant in practice, and the transformer plug pack is going to eliminate the ground loop. Otherwise you'd need some means of providing galvanic isolation, like a USB isolator or line isolator.

The more expensive Jotunheim with its balanced I/O can afford being IEC Class I... its SE input would pose the same problems but at least you would be able to use the balanced input with a suitable adapter cable and eliminate the problem this way. The Asgard has no such option. Perhaps not the most well-thought-out design.

 

[Offler]

My board did not come with any optical outputs, and I do not have anything that can accept it as an input either, as I do not have a dedicated DAC yet.

May i ask which mainboard do you have?

Also aside from Toslink, you can transfer sound from PC to a DAC over Bluetooth.

 

[Smychavo]

May i ask which mainboard do you have?

Also aside from Toslink, you can transfer sound from PC to a DAC over Bluetooth.

MSI B350 PC Mate, just to reiterate.

A Magni Heresy / IEMagni is no slouch. It only has 0.6 dB less gain and about 2 dB less maximum output than the Asgard 3 (50 ohm load)... unless you were right on the edge to begin with, that's going to be irrelevant in practice, and the transformer plug pack is going to eliminate the ground loop. Otherwise you'd need some means of providing galvanic isolation, like a USB isolator or line isolator.

The more expensive Jotunheim with its balanced I/O can afford being IEC Class I... its SE input would pose the same problems but at least you would be able to use the balanced input with a suitable adapter cable and eliminate the problem this way. The Asgard has no such option. Perhaps not the most well-thought-out design.

So, to also reiterate things here again, my ground loop is being produced from two devices total, and it's coming through the board, regardless of what input I use as my output to my amp. In that effect, I can't help but ask, but with the IEMagni, how would the transformer fix the loop? Does it simply not have a ground pin? If I remember correctly, single ended amps are by design, going to pick up noise by nature of how the electrical signals are carried. I would greatly appreciate some clarification.

 

[wwenze]

"Ground noise" happens because the ground voltage of your source and your load/receiver are different. But the signal voltage is the same.
So voltage sent by source = Signal - Ground(source), while voltage seen by load = Signal - Ground(load)
Signal voltage can be assumed to be the same on both ends, but the two ground voltages can be different, hence the noise.
(If you are interested to know why the above sentence happens, we can continue that discussion in further detail.)

But when you are connecting via a transformer, the grounds of both equipment are not connected to each other (not via the signal cable, anyway). Instead, the voltage on the source side winding generates a voltage on the load side. This voltage is generated across load input pin and load ground. So, even if the ground voltage between source and load is different, this difference does not carry over. This galvanic isolation is useful in preventing things at different DC voltages from frying each other, but it also helps to block ground noise as a result.

 

[Krusty09]

I'm hearing ground noise from my PC source. It's a custom tower PC, which through a Apple Type-C to 3.5 mm, connects to a Schiit Asgard 3 which powers my HE-4XX headphones. Noise is source-agnostic, connecting to mobile devices removes the noise completely. While PC headphone out, or USB ports, and by extention, the headphone output of my monitor outputs noise, and sounds like ground hum mixed with computer activity, which changes depending on the current load on my system, like gaming, or even moving a tab around.

I'm contemplating whether to buy balanced amp and DAC, or to try my hand at isolating the usb source, or my pc, though in that I have a few questions:

is it safe for a isolation transformer to be plugged into a power strip?
Schiit's Unison USB supposedly isolates the USB input, would adding the ESS DAC for Asgard 3, or a Modi 3+ solve my issue, or would any other SE DAC offer the same isolation on its USB input?
Lastly, would balanced simply be a better long term solution? If so, I'd rather do that than try to dance around this issue if it's the be-all, end all solution to my problem.

On a different note, I've watched Amirim's video on understanding ground, and on balanced audio, but I'm still unsure of myself as to what is the ideal solution in my scenario.

Hello .

I think I may have an easy fix but I'm not sure really of your setup . First are there more then one outlet the the stereo equipment is plugged into ? If so try plugging all into the same outlet and if it's a double gang outlet plug it all into only one side of it use a power strip if need be.

The thing is most construction has a 3 phase electric to a breaker panel and depending on what phase those outlets are like opposite phases you could have potential between the 2 which almost always causes ground problems.

Most breaker panels are setup with 2 rows of breakers and you can just go down the row and count from the top A,B,C LEFT AND A,B,C on the right and then shut off the breakers and you will know what phase you are on .

Ultimately you want your stereo equipment to all be on the same phase to aliminate the hum.

I just did this and it solved a problem I had.

 

[Smychavo]

Hello .

I think I may have an easy fix but I'm not sure really of your setup . First are there more then one outlet the the stereo equipment is plugged into ? If so try plugging all into the same outlet and if it's a double gang outlet plug it all into only one side of it use a power strip if need be.

The thing is most construction has a 3 phase electric to a breaker panel and depending on what phase those outlets are like opposite phases you could have potential between the 2 which almost always causes ground problems.

Most breaker panels are setup with 2 rows of breakers and you can just go down the row and count from the top A,B,C LEFT AND A,B,C on the right and then shut off the breakers and you will know what phase you are on .

Ultimately you want your stereo equipment to all be on the same phase to aliminate the hum.

I just did this and it solved a problem I had.

I live with family for the time being, so messing with the breakers of the house is out of the question.

"Ground noise" happens because the ground voltage of your source and your load/receiver are different. But the signal voltage is the same.
So voltage sent by source = Signal - Ground(source), while voltage seen by load = Signal - Ground(load)
Signal voltage can be assumed to be the same on both ends, but the two ground voltages can be different, hence the noise.
(If you are interested to know why the above sentence happens, we can continue that discussion in further detail.)

But when you are connecting via a transformer, the grounds of both equipment are not connected to each other (not via the signal cable, anyway). Instead, the voltage on the source side winding generates a voltage on the load side. This voltage is generated across load input pin and load ground. So, even if the ground voltage between source and load is different, this difference does not carry over. This galvanic isolation is useful in preventing things at different DC voltages from frying each other, but it also helps to block ground noise as a result.

I appreciate the brief clarification. I'm fully aware that galvanic isolation is a definite solution to my problems. However, considering that an supposedly competent isolation transformer online costs nearly as much as buying fully balanced hardware (Magnius/Modius, D10 Balanced/SMSL SP200, Geshelli J2/E2), and from reading mixed reviews on USB isolators, I'm just not sure whether that's the path I should spend my money on for fixing this issue when there's an upgrade path for my hardware that is very alluring to me that would also seem to solve my problems.

 

[Krusty09]

I live with family for the time being, so messing with the breakers of the house is out of the question.


I appreciate the brief clarification. I'm fully aware that galvanic isolation is a definite solution to my problems. However, considering that an supposedly competent isolation transformer online costs nearly as much as buying fully balanced hardware (Magnius/Modius, D10 Balanced/SMSL SP200, Geshelli J2/E2), and from reading mixed reviews on USB isolators, I'm just not sure whether that's the path I should spend my money on for fixing this issue when there's an upgrade path for my hardware that is very alluring to me that would also seem to solve my problems.

Ok. Do it this way. Get a meter and
measure the voltage between the hot terminals of the two specific outlets.
This would be the short blade in each of the outlets. If you see zero volts, they're on the same leg of the house circuits and 8f you see 240 they are on different legs and this is probably where you problem is. Use an extension cord if you need to . Remember to set the meter to 600 volts sice you will be measuring 240.

 

[Offler]

MSI B350 PC Mate, just to reiterate.

Checked that out, because I found unusual to have a mainboard without Toslink.

I see two options:
a) Bluetooth adapter
Within WIFI card or standalone, with support of aptX HD, and same for the receiver/amplifier.

b) Dedicated soundcard
Nothing fancy, just to have toslink.

Both will solve ground loops and noise from PC.

 

[Chitami]

Check this thread out

Schiit Vidar - Sensitive to USB noise?

Hi, Have you tried to convert usb signal to toslink then input toslink to Modi 3+. It sound simple hope it fix your ground loop like many ppls who have modius ground loop success. Douk Audio USB Converter XMOS XU208

www.audiosciencereview.com

 

[spiritofjerry]

If anyone in the future stumbles across this thread and they are getting USB noise, it's almost definitely a ground loop issue. If your DAC is not powered by USB, and is independently powered, you can try this easy fix: place some kapton tape over the 5v and ground pins on the USB cable that connects to the DAC. Solved my problem, no ground loop isolator needed. Just fed the DAC data only from USB, and everything worked.

 

[pinyuszka]

If anyone in the future stumbles across this thread and they are getting USB noise, it's almost definitely a ground loop issue. If your DAC is not powered by USB, and is independently powered, you can try this easy fix: place some kapton tape over the 5v and ground pins on the USB cable that connects to the DAC. Solved my problem, no ground loop isolator needed. Just fed the DAC data only from USB, and everything worked.

Can you illustrate with pictures? I would be interested in this solution!

 

[spiritofjerry]

Can you illustrate with pictures? I would be interested in this solution!

You can easily find the pinout for USB cables with a quick Google search. Just try covering the 5v and ground pins.

 

[pinyuszka]

You can easily find the pinout for USB cables with a quick Google search. Just try covering the 5v and ground pins.

I have an audioquest cobalt usb sound card.
I'm struggling with a ground loop problem.
If I had an external powered usb hub and covered the 5v and grounding pint ... would it work?

 

[spiritofjerry]

I cannot say. It can only work at all if your soundcard is externally powered, it cannot be powered by USB.