Edit: the real issue is background radio interference.

[Human Bass]

Resolution edit: The T2 Plus I was using had some current leakage and antenna effect. The amp itself is flawless. No hiss or hum even max volume with other phones.

First it was being over sensitive to radio interference even when I used short, well shielded rca.

Now it is giving me electrical shocks to the left ear! Even without any dac/source connected to it!! I tested the same phones in other devices and no shock.

The serial number is 2008654137.

Calling @JohnYang1997 urgently.

Hard to know if it is really the amp or the power supply that came with being faulty, but even if it is the ps, it is a integral part of the package.

Edit: the fault may be in the iem Im using (T2 Plus, metal shell and all). I will do futher testing.

Still the background noise I was getting from the A50S was abnormally high for such a device that was designed to be super low noise and distortion.

 

[fieldcar]

Can you try to rotate the ac adapter in the outlet and see if it still shocks you?

 

[Human Bass]

Can you try to rotate the ac adapter in the outlet and see if it still shocks you?

Did that 2x, still got the stinged.

 

[Hemi-Demon]

Its $200, return immediately and either replace it or move on to something else. I would not risk discomfort and potential headphone damage while waiting for troubleshooting. Sorry this is happening to you.

 

[fieldcar]

Did that 2x, still got the stinged.

Yeah. It sounds like the power supply is the issue. I would return it and get a replacement.

 

[Blumlein 88]

What kind of headphones are you using? If you have a multi-meter check for voltage between what shocks you on the phones and the grounded case. See what sort of readings you get.

 

[Human Bass]

To send something back from Brazil to China is kinda tricky heh. But I trust Topping will provide a solution. I love my D50S and I knhow the A50S is an amazing product. I may try another ps, 15v isnt hard to find.

 

[Human Bass]

What kind of headphones are you using? If you have a multi-meter check for voltage between what shocks you on the phones and the grounded case. See what sort of readings you get.

Right now a Tin T2 Plus, it is sensitive but not super (32ohm). I tested on low gain, both the SE and Bal outs.

 

[Human Bass]

Guys, to be fair, the fault may be in the iem. Im gonna do more tests using the iem connected to my notebook audio out.

https://www.reddit.com/r/headphones/comments/cqa2ye

 

[Blumlein 88]

Right now a Tin T2 Plus, it is sensitive but not super (32ohm). I tested on low gain, both the SE and Bal outs.

I was looking for voltage readings. See what kind of stray voltage you are dealing with here.

 

[fieldcar]

I was looking for voltage readings. See what kind of stray voltage you are dealing with here.

I wonder if these peaks may be too short in duration for a multimeter to read. Dang. I can't think of any other solution. I'm sure he was really excited to get some hifi goodness rather than electrostatic shocks pumped into his ears.

 

[Human Bass]

But there are certainly more tests to be done. I need get another pair of phones to test.

 

[JohnYang1997]

First it was being over sensitive to radio interference even when I used short, well shielded rca.

Now it is giving me electrical shocks to the left ear! Even without any dac/source connected to it!! I tested the same phones in other devices and no shock.

The serial number is 2008654137.

Calling @JohnYang1997 urgently.

Hard to know if it is really the amp or the power supply that came with being faulty, but even if it is the ps, it is a integral part of the package.

Edit: the fault may be in the iem Im using (T2 Plus, metal shell and all). I will do futher testing.

Still the background noise I was getting from the A50S was abnormally high for such a device that was designed to be super low noise and distortion.

1, There's no ground to speak of. So it can't be shock. If some discharge happens or some tingling happens. That's leakage current. SMPS has known for higher leakage current. The IEMs should have their housing isolated from internal wiring, or things like this will happen. Same with listening to music through phone with charger plugged in(rare these days as we don't have headphone jack anymore).

2, What type of noise are you experiencing this time? Don't test noise performance with input not connected.

 

[Asylum Seeker]

Id look into the T2+. My T3 shocks when my smartphone is plugged in.

 

[Blumlein 88]

Yes, try the T2's in another device and try other phones in the Topping. Looking at the cable construction my money is on a wiring fault in the phones.

 

[Human Bass]

1, There's no ground to speak of. So it can't be shock. If some discharge happens or some tingling happens. That's leakage current. SMPS has known for higher leakage current. The IEMs should have their housing isolated from internal wiring, or things like this will happen. Same with listening to music through phone with charger plugged in(rare these days as we don't have headphone jack anymore).

2, What type of noise are you experiencing this time? Don't test noise performance with input not connected.

Tomorrow (late night here now) i will get a pair of headphones to run more tests.

I still hear faint radio in the background, even with the volume pot very low and using well shielded cables. But now i fear the t2 plus may be acting up. I will test the pre out on my speakers.

 

[amirm]

Did that 2x, still got the stinged.

My Dell laptop used to do this. As John explained, it is harmless mains leakage. The safety standards allow fair bit of it since it is not a health risk and just some annoyance. You can use a different power source and it may go away.

 

[JohnYang1997]

Tomorrow (late night here now) i will get a pair of headphones to run more tests.

I still hear faint radio in the background, even with the volume pot very low and using well shielded cables. But now i fear the t2 plus may be acting up. I will test the pre out on my speakers.

That's unbalanced connection for you man. The input impedance is low enough to dampen any realistic interference.
Maybe you can try short the input by connect the other ends (that's normally connected to source) of left and right to each other. This way you will eliminate the affect of upstream. So if you still hear interference, then either it's the interference is abnormally high in your area(can happen), or it's a faulty unit.

If the noise is gone then it's the upstream. Then look for USB noise, ground loop, isolation, using toslink etc. Or up your game and get some balanced devices.

 

[Human Bass]

So good news. I tested the A50S pre-out in my active speakers. I set the speakers to their max volume and the A50S to its minimal, to see if any radio noise would leak to the speakers. It didnt. =D

 

[Human Bass]

I unburied some cheap Sony iems from the bottom of my drawer and...no noise of any kind! No electrical leakage either. What was really faulty were the T2 Plus. Sorry for the drama.