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Amplifier distortion at low gain but not on high gain

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#1
Recently, I suddenly heard distort sound from my rigs, the sound is like electric & buzzing sound from my amplifier. This sound get louder when I turn my volume knob smaller, or I plug simultaneously a 6.3 adapter to my other jack (I'm playing music via XLR output). When I changed to high gain, distort sound disappear and black background, switched back to low gain, and the distortion re-appear. Disconnect and reconnect the headphone after a while also make distort sound disappear.

Is there anything I could do to solve the problem, another thing to note is this is after I switched my HD800, could a cable change can affect the amplifier itself.
Thanks in advance.
 

solderdude

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#2
Could be a groundloop, a lack of proper grounding, dodgy interlink cable or a faulty device.

Hard to say without knowing which devices you are talking about and how they are connected to each other and how they are connected to mains.
 
OP
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Thread Starter #3
Could be a groundloop, a lack of proper grounding, dodgy interlink cable or a faulty device.

Hard to say without knowing which devices you are talking about and how they are connected to each other and how they are connected to mains.
Ok. So my gear are: Aune S6 PRO connect to my PC (I grounded my PC), XLR out to iHA-6. Both Aune and iHA-6 are connected to power socket but my electric socket doesn't have ground pin (I use adapter 3pin to 2pin)
 

solderdude

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#5
Ok. So my gear are: Aune S6 PRO connect to my PC (I grounded my PC), XLR out to iHA-6. Both Aune and iHA-6 are connected to power socket but my electric socket doesn't have ground pin (I use adapter 3pin to 2pin)
remove the 3pin-2pin socket and connect the 3 pin plugs to a proper 3 pin wall socket/extension cord first
 

solderdude

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#7
I can't say yet.
To do fault finding first one needs to have the basics correct.
In this case power supply and grounding.
When this is O.K. and there are still issues it is time to look further into the matter with some other tests.
 
OP
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Thread Starter #8
remove the 3pin-2pin socket and connect the 3 pin plugs to a proper 3 pin wall socket/extension cord first
Unfortunately, my house wall socket is not grounded, before I also tried to connect to extension cord, but the source is still not properly grounded. However, the problem wasn't there before, it is just after I switched to the Norne Draug v3 cable that I experienced this, don't know if it is just a coincidence or not. And it only happens to XLR output
 

LTig

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#10
Unfortunately, my house wall socket is not grounded, before I also tried to connect to extension cord, but the source is still not properly grounded. However, the problem wasn't there before, it is just after I switched to the Norne Draug v3 cable that I experienced this, don't know if it is just a coincidence or not. And it only happens to XLR output
Switch back to the cable you used before and you will know.
 

solderdude

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#12
buy a cheap XLR cable from a music/guitar store.
These usually are perfect for the job and better than the exotic ones.
 
OP
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Thread Starter #13
buy a cheap XLR cable from a music/guitar store.
These usually are perfect for the job and better than the exotic ones.
Today I tested, when the problem occur, it disappears when I hold my left side headphone cable?? How can this happen?
 

solderdude

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#14
It's a common mode current that get's grounded through you when you touch the cable.
You need to ground the amplifier so it is grounded through it.
Either 3-prong mains or waterpiping (when all copper) or central heating (all metal piping)
 
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