unexplainable loud buzzing noise when using my Aune x1s?

[Aubergine]

I have been scratching my head a lot lately trying to figure out what's " wrong" with my Aune x1s when plugging in a pair of headphones whenever i touch the volume control or anywhere on the case there is a loud buzzing noise i originally thought this might be some kind of grounding issue but it exists on all the inputs even toslink!

Recently i purchased an Aune x7s to complement my Aune x1s and when used in combination i can touch the x1s case and there is no noise anymore but curiosity took over so i set it up with 20db gain and plugged in a pair of relatively efficient headphones.. the sennheiser 598

And now i could hear a buzzing noise similar to the one i experienced before but this noise does not change if i touch the aune x1s or the aune x7s

I then used my Soundblasterx g6 when using just usb the Aune x7s is quiet when i changed and used toslink on my G6 the same noise i heard before with my aune x1s came back it was just a little bit quieter

Anyone know why this is happening?

 

[solderdude]

This is a classic case of a groundloop.
You are creating the groundloop when touching the volume control.
When connecting the x7s the groundloop takes a lower impedance path via that device.

It is a grounding issue without any doubt.
Solving it takes a lot of experimentation.

 

[Aubergine]

This is a classic case of a groundloop.
You are creating the groundloop when touching the volume control.
When connecting the x7s the groundloop takes a lower impedance path via that device.

It is a grounding issue without any doubt.
Solving it takes a lot of experimentation.

But aint Toslink suppose to be immune to groundloops? So how can it happen both with my Aune x1s and my Soundblaster when using Toslink? Or am i just missing something

 

[solderdude]

Your X1 is connected to mains via its powercord/adapter. This has a leakage current. Then that current (which is very low) finds its path to ground via your body when touching it.
Connecting the x7s changes the path the current takes via the x7s power supply.

 

[Aubergine]

Your X1 is connected to mains via its powercord/adapter. This has a leakage current. Then that current (which is very low) finds its path to ground via your body when touching it.
Connecting the x7s changes the path the current takes via the x7s power supply.

How would i fix that? I looked around and found the gadget i used in the past when i thought i was cursed with groundloops the idefender it says it disconnects the ground from the computer i did a test

I plugged my Aune x1s straight into the idefender which i now power with a 5 volt power supply it was plugged straight into my computer i made sure that the computer and the idefender draw power from the same outlet the noise is still there whenever i touch the case

Now i did the same thing with toslink plugged a usb to toslink converter into the idefender the toslink goes into the aune x1s no more noise when touching the case! Okay i have checked it again there is still noise when touching the case but it is a lot quieter for some reason coax and usb simply creates more noise
So even though i have disconnected the earth plugged the Aune into the same outlet as my pc usb coax toslink have grounding issues maybe my aune x1s is broken somehow? I cannot ground it no matter what i try

 

[daftcombo]

To be sure, you might try to touch the unit while jumping and see if the buzzing noise briefly stops.

 

[solderdude]

Try to run a wire from the RCA shield of the Aune to ground.
Ground can be waterpiping (needs to be all copper and connected to a non-painted part) or central heating (also when connected with metal piping and needs to be connected to bare metal.
Another option is to use safety ground of a wall socket.
I assume your PC/equipment is connected using 3-prong wall outlet.

The X1s is not broken.

Also does the same happen when you touch the RCA shield on the back ?
Is the volume knob made out of metal ?
maybe the volume control itself is not grounded internally. In the latter case you will need to open it up and correct it.

 

[Aubergine]

Try to run a wire from the RCA shield of the Aune to ground.
Ground can be waterpiping (needs to be all copper and connected to a non-painted part) or central heating (also when connected with metal piping and needs to be connected to bare metal.
Another option is to use safety ground of a wall socket.
I assume your PC/equipment is connected using 3-prong wall outlet.

My outlets have two prongs if i touch any part of the Aune x1s when plugging headphone into it there is a loud buzzing noise including the RCA connections on the back much quieter though when using toslink i guess grounding can change in severity? somehow

The only wires i have are speaker wires i tried using the copper tips to ground the RCA to a heating element it didn't work i just felt really stupid

What is funny is i have used other Dacs with built in headphone amps and none of them behave like the Aune does if i plug my V90 HPA into my computer and plug a pair of headphones into it its dead quiet

 

[Neutron]

My outlets have two prongs if i touch any part of the Aune x1s when plugging headphone into it there is a loud buzzing noise including the RCA connections on the back much quieter though when using toslink i guess grounding can change in severity? somehow

The only wires i have are speaker wires i tried using the copper tips to ground the RCA to a heating element it didn't work i just felt really stupid

What is funny is i have used other Dacs with built in headphone amps and none of them behave like the Aune does if i plug my V90 HPA into my computer and plug a pair of headphones into it its dead quiet

You can connect the rca/usb to another device nearby despite you don’t use it.

 

[Aubergine]

You can connect the rca to another device nearby despite you don’t use it.

I tried this just now it didn't make a difference and also if i use the aune x1s just as a dac just using the line outs the noise is still there though it is a lot quieter

for me to be able to hear it on my aune x7s i had to put gain to 20db and use my 598s at max volume if i did listen to anything at that volume i would go deaf in a second but i still dont like that the noise is there i mean have no idea how this adversely affects the Aune x1s measured performance

 

[Neutron]

I tried this just now it didn't make a difference and also if i use the aune x1s just as a dac just using the line outs the noise is still there though it is a lot quieter

for me to be able to hear it on my aune x7s i had to put gain to 20db and use my 598s at max volume if i did listen to anything at that volume i would go deaf in a second but i still dont like that the noise is there

Does it make a difference if you use it as an amp via RCA input?

Some residual buzz is normal with many devices.

 

[Neutron]

I tried this just now it didn't make a difference and also if i use the aune x1s just as a dac just using the line outs the noise is still there though it is a lot quieter

for me to be able to hear it on my aune x7s i had to put gain to 20db and use my 598s at max volume if i did listen to anything at that volume i would go deaf in a second but i still dont like that the noise is there i mean have no idea how this adversely affects the Aune x1s measured performance

I somehow recalled my first diy amp. It created a buzz when i touched volume pot. Then i was told to ground the pot by running a wire from a ground point to the metal part of the pot, and it fixed the problem.

I don’t know if this is similar to your problem. It could be the case connected to the pot, but not to pcb ground.

 

[Aubergine]

Does it make a difference if you use it as an amp via RCA input?

Some residual buzz is normal with many devices.

If i use the aune x1s only as a headphone amp meaning just using the line in the same noise appears if i plug my headphones straight into the Soundblasterx g6 and ignore the x1s no noise at all

 

[solderdude]

Do you have 3 prong power outlets ?

 

[Neutron]

If i use the aune x1s only as a headphone amp meaning just using the line in the same noise appears if i plug my headphones straight into the Soundblasterx g6 and ignore the x1s no noise at all

You might have two noise sources here. You probably should make a table like this.

Setup. Connection used. Noise(Y/N). Note(how noise changed or behave, i.e. increase with increasing volume)

One thing you can do, in addition, is download a 60Hz test tone(for example), and check if you are hearing that particular frequency, which is often power/grounding related.

 

[Aubergine]

You might have two noise sources here. You probably should make a table like this.

Setup. Connection used. Noise(Y/N). Note(how noise changed or behave, i.e. increase with increasing volume)

One thing you can do, in addition, is download a 60Hz test tone(for example), and check if you are hearing that particular frequency, which is often power related.

Its the same noise but i will attempt to describe it in more depth

if i plug headphones into the aune x1s and touch it anywhere a loud buzzing noise happens it can slightly change in volume often if i touch it again the noise goes away the overall volume is a lot lower if using toslink the noise is still there if i just use it as an headphone amp when using it as a dac the same noise can be heard but its much more quiet and can only be heard at very loud volumes the noise is different when used as a dac in the sense that its now a constant buzzing that doesn't change in volume and it doesn't go away

The power cable have three prongs the outlet has only two that i can see im not an electronical engineer so i dont know here i took photos if i found out anything today is that i really need to clean my outlets.. and not get electrocuted

 

[Neutron]

Its the same noise but i will attempt to describe it in more depth

if i plug headphones into the aune x1s and touch it anywhere a loud buzzing noise happens it can slightly change in volume often if i touch it again the noise goes away the overall volume is a lot lower if using toslink the noise is still there if i just use it as an headphone amp when using it as a dac the same noise can be heard but its much more quiet and can only be heard at very loud volumes the noise is different when used as a dac in the sense that its now a constant buzzing that doesn't change in volume and it doesn't go away

The power cable have three prongs the outlet has only two that i can see im not an electronical engineer so i dont know here i took photos if i found out anything today is that i really need to clean my outlets.. and not get electrocuted

I still recommend you to systematically describe the issue. A table helps others understand you faster.

i just checked measurements on your dac, it does has some low frequency background noise via HP out as it uses a transistor based circuit there. But as you can see it’s not power related as frequency is higher, and it is unique to HP out. The buzz you hear while you touch the case, it’s a different kind of noise might sound similar as frequencies are close.



That’s why i advised you to confirm with test tone and tabulate your findings. You can google audio test tone generator. Try 60Hz and 100Hz.

 

[Aubergine]

You might have two noise sources here. You probably should make a table like this.

Setup. Connection used. Noise(Y/N). Note(how noise changed or behave, i.e. increase with increasing volume)

One thing you can do, in addition, is download a 60Hz test tone(for example), and check if you are hearing that particular frequency, which is often power/grounding related.

I still recommend you to systematically describe the issue. A table helps others understand you faster.

i just checked measurements on your dac, it does has some low frequency background noise via HP out as it uses a transistor based circuit there. But as you can see it’s not power related as frequency is higher, and it is unique to HP out. The buzz you hear while you touch the case, it’s a different kind of noise.

View attachment 66908

That’s why i advised you to confirm with test tone and tabulate your findings. You can google audio test tone generator. Try 60Hz and 100Hz.

Its much higher frequency and not a constant tone more like an angry somewhat higher pitched buzzing noise it reminds me off what happens if you unplug rca cables while you have set your volume up to a moderate level or if you just unplug one of them and touch it with your fingers not recommended of course but it is the closest that i can describe it that 60hz tone is quite soothing actually if i was hearing that i might consider it a bonus

 

[solderdude]

Try to connect the RCA shield to the metal prongs of the mains outlet.
Be SURE to not touch the contacts in the holes.
Only to one of the two metal thingies sticking out of the wall socket.
That definitely will be grounded.

 

[Aubergine]

Try to connect the RCA shield to the metal prongs of the mains outlet.
Be SURE to not touch the contacts in the holes.
Only to one of the two metal thingies sticking out of the wall socket.
That definitely will be grounded.

Think i save that one for someone who is braver than me
Does it audibly degrade the sound at lower volumes even though you cant hear it? With my aune x7s i can only hear it at 20db gain with low impedance headphones as long as its not making the audio worse somehow at much lower real life listening levels i dont really care but im not sure