Why do different USB ports sound different?

[LongKick64]

I have an Intel NUC10i5FNH mini-computer and a Topping MX3s DAC. Why does the DAC sound different when connected to different USB ports? Both USB ports are USB 3.1 gen2. This is not self-hypnosis, I even did blind testing to make sure. Which USB port should I choose? The one that I like the sound from more?

 

[MAB]

I have an Intel NUC10i5FNH mini-computer and a Topping MX3s DAC. Why does the DAC sound different when connected to different USB ports? Both USB ports are USB 3.1 gen2. This is not self-hypnosis, I even did blind testing to make sure. Which USB port should I choose? The one that I like the sound from more?

Perhaps you should detail your blind testing protocol.
And, if one sounds different, trivial to measure.
If you provide that data, we can have a discussion. Otherwise, just like the other anecdotes.

 

[solderdude]

Yep, what is considered 'I even did a blind test'.
Easy to record the analog output which should differ IF the sound different.
So far ... just another anecdotal until some hard proof is shown.... and even then... it is even possible to 'fake' such proof (measurements).

 

[krabapple]

Seems we need some sort of giant blinking banner on this site -- or on every thread creation page -- that says

*IT'S NOT ENOUGH TO JUST CLAIM YOU DID A BLIND TEST.*

 

[LongKick64]

Cool forum! I was hoping for something like: maybe different USB ports, react differently to the noise of internal components such as the motherboard, etc., that's why I hear the difference in headphones. Maybe buying a galvanic decoupler like Topping HS01 or HS02 will help solve the problem. But as a result, they write all sorts of nonsense here. Ok.

 

[solderdude]

What would CAUSE USB ports to have a 'sound' and how could they differ ?
What would be different in the digital 'packages' that would change the output of a DAC ?

 

[LongKick64]

What would CAUSE USB ports to have a 'sound' and how could they differ ?
What would be different in the digital 'packages' that would change the output of a DAC ?

Interference in the form of noise, which is abundant inside the small computer case, gets onto the USB bus and then from there via the USB cable gets to the DAC It is possible that some USB port is more susceptible to this interference.

 

[Doodski]

Interference in the form of noise, which is abundant inside the small computer case, gets onto the USB bus and then from there via the USB cable gets to the DAC It is possible that some USB port is more susceptible to this interference.

Hi @LongKick64 please detail how you did your blind listening test before going further...

 

[DVDdoug]

maybe different USB ports, react differently to the noise of internal components such as the motherboard, etc., that's why I hear the difference in headphones.

You would have said "noise", or you would have described the noise, as hiss, hum, buzz, whine, clicking, etc.

Sometimes people don't have the language to describe what they're hearing but with electronics it's usually noise, distortion or frequency response, or the left channel is quieter than the right, etc.

 

[solderdude]

Interference in the form of noise, which is abundant inside the small computer case, gets onto the USB bus and then from there via the USB cable gets to the DAC It is possible that some USB port is more susceptible to this interference.

How would noise on a USB port make a DAC sound different ?
Has there ever been a 'clean' USB port on any device that doesn't have some common mode noise on it ?
Even some differential noise on the Vbus or data would not make a DAC sound different.
It could make different sounds (that aren't supposed to be there) though a ground loop but not make the DAC 'sound' different.

 

[Todd k]

OMG !!!! Must not have been lurking around here too long. I’am pretty sure that digital transfer thing has been proven over an over.

 

[krabapple]

Cool forum! I was hoping for something like: maybe different USB ports, react differently to the noise of internal components such as the motherboard, etc., that's why I hear the difference in headphones. Maybe buying a galvanic decoupler like Topping HS01 or HS02 will help solve the problem. But as a result, they write all sorts of nonsense here. Ok.

What's nonsensical is to expect people at Audio Science Review to just accept what on its face is very unlikely, without better evidence. OK?

 

[LongKick64]

Hi @LongKick64 please detail how you did your blind listening test before going further...

Turned away from the computer and asked my brother to change the USB port. He played the same track for me. I guessed which USB port was playing 10 out of 10 times.

You would have said "noise", or you would have described the noise, as hiss, hum, buzz, whine, clicking, etc.

Sometimes people don't have the language to describe what they're hearing but with electronics it's usually noise, distortion or frequency response, or the left channel is quieter than the right, etc.

One USB port sounds cleaner, you can hear less noise (like a radio makes noise when it can't catch a frequency), the other sounds dirtier, you can hear noise. The USB port that sounds noisier seems to have more detail in the headphones, more high frequencies, tighter bass. The one that sounds cleaner, the sound with it seems less detailed, the bass is slower and fatter.

How would noise on a USB port make a DAC sound different ?

Interference from the USB port goes through the USB cable directly to the DAC and does its job there.

 

[solderdude]

Interference from the USB port goes through the USB cable directly to the DAC and does its job there.

What 'job' would that be other than become audible as an audio signal that isn't supposed to be there ?
It would be audible when you play music attenuated at the source or in a silent intro and might even be there when nothing is playing.
If that is the case then something is wrong in the DAC itself (ground loop) and the only way would be to break the ground loop.

 

[LongKick64]

What 'job' would that be other than become audible as an audio signal that isn't supposed to be there ?
If that is the case then something is wrong in the DAC itself (ground loop) and the only way would be to break the ground loop.

So, this can’t even happen theoretically?

 

[LongKick64]

What's nonsensical is to expect people at Audio Science Review to just accept what on its face is very unlikely, without better evidence. OK?

Yes, I already realized that I had the wrong address. LOL!

 

[LongKick64]

and the only way would be to break the ground loop.

Are you talking about that thing I wrote about above?

 

[LongKick64]

I don't have any grounding at all in my house

 

[MAB]

Turned away from the computer and asked my brother to change the USB port. He played the same track for me. I guessed which USB port was playing 10 out of 10 times.


One USB port sounds cleaner, you can hear less noise (like a radio makes noise when it can't catch a frequency), the other sounds dirtier, you can hear noise. The USB port that sounds noisier seems to have more detail in the headphones, more high frequencies, tighter bass. The one that sounds cleaner, the sound with it seems less detailed, the bass is slower and fatter.

Interference from the USB port goes through the USB cable directly to the DAC and does its job there.

You could be helped if you had measurements, or perhaps a complete and meaningful description of the sound, or the noise, or the differences, or whatever.
Any tech would do the same, wouldn't care about your blind test, just want to know the symptom.

Sounds like you may have a noise on your USB port of your computer. Like one USB port is picking up noise from the graphics card, etc. If so, there are some isolation devices that can help. Optical eliminates this. Have you tried that?

 

[LongKick64]

Sounds like you may have a noise on your USB port of your computer. Like one USB port is picking up noise from the graphics card, etc. If so, there are some isolation devices that can help. Optical eliminates this. Have you tried that?

I don't have an optical cable, so no, I haven't tried it. Thanks for the idea! I'll have to try it.