Topping A30Pro Bug/Defect, Help!

[masterdragon]

I recently bought 1 Topping A30Pro from AliExpress, from Shezhenaudio (oficial store), 1 month ago.

Been using and thinking i was finally in heaven for have finally found the amplifier with power and audio signature i was always looking for. But i have not had time to test all my musics, so my happiness lasted until...
Until i began playing some different kind of music or videos with different audio nuances/frequency along the songs, and i found something im not understanding why is happening:

When in High Gain, volume over 65%, at some SPECIFIC parts of some musics or videos, the topping just turn the LED OFF, 1 second later mutes the sound, and come back, like the video above shows.

Its bizarre and i don't understand why is it. Any thoughts?
Im using P2 to RCA input only (PC rear output to A30Pro)
220v here and i have been using the same wall socket + RCA-P2 cable for plenty of other equipments (Magni Heresy, Fiio K5 Pro), since always = 100% working, never had any problem

Its bizarre that this "BUG" occurs everytime i reach those various specific second of those songs, or videos (and yes, played the same file of these videos and songs on another PC, amp, etc, etc, all fine). Its like if some specific change of frequency along some music or video is making the A30Pro trigger some kind of BUG in its design (thats what it seems to me).
What do you guys think? Defective inner part? I hope i can RMA

 

[unpluggged]

Looks like the DC protection kicks in. It would be much easier if you told us what is this specific track that is playing and at which exact time position of the track the amp switches itself off.

 

[IAtaman]

Another possibility is the over-current protection. What is the headphone you are driving with A30pro?

Which output of the PC you are using, line out I presume? Line out can go as high as 2V and A30Pro has 14db gain at high so the output voltage might be as high as 10V. If you are trying to drive 16ohm headphones with that voltage, you are pushing A30Pro out of specs.

 

[Dunring]

I've had several of those and had them with IEMs up to the He6se and never noticed that problem. Short of swapping out the power cable or trying different headphones, not sure there's much more to do than RMA it. Are you running it in ground mode or lift? Ground is always preferred.

 

[masterdragon]

I've had several of those and had them with IEMs up to the He6se and never noticed that problem. Short of swapping out the power cable or trying different headphones, not sure there's much more to do than RMA it. Are you running it in ground mode or lift? Ground is always preferred.

Ground.
I tried to put on lift too to see if could stop somehow, but happens the same.

 

[masterdragon]

Looks like the DC protection kicks in. It would be much easier if you told us what is this specific track that is playing and at which exact time position of the track the amp switches itself off.

Looks like the DC protection kicks in. It would be much easier if you told us what is this specific track that is playing and at which exact time position of the track the amp switches itself off.

https://whyp.it/tracks/107737/high-sea?token=wSIvE

at exactly: 0:40

 

[masterdragon]

Another possibility is the over-current protection. What is the headphone you are driving with A30pro?

Which output of the PC you are using, line out I presume? Line out can go as high as 2V and A30Pro has 14db gain at high so the output voltage might be as high as 10V. If you are trying to drive 16ohm headphones with that voltage, you are pushing A30Pro out of specs.

ATH-M50X

Motherboard Gigabyte Z370 HD3P (Great onbard audio by the way, more natural sound than DACs to my taste) (https://www.gigabyte.com/FileUpload/BR/KeyFeature/813/images/model_intro_1920.png)
Green line out.
Never had nor still have any problems with no other amp or pre-amp i plugged in.

And again, its so strange that i can watch and listen to 70% of my things here without happening it, but for the 30% where theres audio "flutuation" it happens, like if some specific frequencies or abrupt change of audio frequency at specific parts that is triggering this "bug". Anyway im returning it, but i hope my issue can help other people.

Im gonna try to get 1 new A30Pro cuz i really have found the best audio signature + volume i was looking for, if wasnt just because of this defect, i would be feeling whole

​

 

[masterdragon]

By the way: something i noticed right now at this moment im writing this comment:

I thought i was just imagining it, but yeah, ive been hearing, sometimes, a click sound that now i caught it coming from the A30Pro turned off (switch put at OFF but AC Cable yet connected).

 

[Jimbob54]

Just out of interest and if you havent already packed it up to return- does that part of that track do it at any volume level? Or just in high gain, high volume? Is the other music that triggers it of a similar nature?

Given the nature of the music I would agree with others, likely DC protection kicking in for a particular beat/ pulse. Now whether it should or not is a different question and one for Topping to answer. Definitely needs sending back anyway.

 

[IAtaman]

ATH-M50X

Motherboard Gigabyte Z370 HD3P (Great onbard audio by the way, more natural sound than DACs to my taste) (https://www.gigabyte.com/FileUpload/BR/KeyFeature/813/images/model_intro_1920.png)
Green line out.
Never had nor still have any problems with no other amp or pre-amp i plugged in.

And again, its so strange that i can watch and listen to 70% of my things here without happening it, but for the 30% where theres audio "flutuation" it happens, like if some specific frequencies or abrupt change of audio frequency at specific parts that is triggering this "bug". Anyway im returning it, but i hope my issue can help other people.

Im gonna try to get 1 new A30Pro cuz i really have found the best audio signature + volume i was looking for, if wasnt just because of this defect, i would be feeling whole

Interesting. On paper nominal impedance of your headphones is 38ohms and Amir measured it 39ohm and flat so at 70% volume, it should not exceed the output specs of A30Pro. You might be exceeding the max power specs of the headphones though.

Luckily, I have the A30Pro and ATH-M50X as well so I gave it a try too. My findings are :

a. You are mad and you WILL make yourself go deaf soon listening this loud. Put that volume down. I could not put the headphone on my head at that volume. This is not a joke.
b. I had exactly the same incident exactly at the same time. My theory is that there is some high level sub-bass content creating some resonance, triggering the amps over current protection. It is not a bug, it is a feature.

Seriously though. Turn that volume knob down.

 

[unpluggged]

https://whyp.it/tracks/107737/high-sea?token=wSIvE

at exactly: 0:40

It pretty much looks like a DC (or nearly DC) signal. So I do think that at high volume levels it is high enough to engage the protection, and it's a very useful feature to have in a headphone amp. I did try it out with my HD6XX, and they made a very disturbing crackling sound when I turned up the volume, so I'd better avoid playing such "musics", at least at higher volumes levels.

 

[masterdragon]

Interesting. On paper nominal impedance of your headphones is 38ohms and Amir measured it 39ohm and flat so at 70% volume, it should not exceed the output specs of A30Pro. You might be exceeding the max power specs of the headphones though.

Luckily, I have the A30Pro and ATH-M50X as well so I gave it a try too. My findings are :

a. You are mad and you WILL make yourself go deaf soon listening this loud. Put that volume down. I could not put the headphone on my head at that volume. This is not a joke.
b. I had exactly the same incident exactly at the same time. My theory is that there is some high level sub-bass content creating some resonance, triggering the amps over current protection. It is not a bug, it is a feature.

Seriously though. Turn that volume knob down.

Good to see we have found a false propaganda of the A30Pro then, or, indeed, again, a BUG indeed, so it cannot handle its own specification.

And no, its not that loud, maybe audiophiles like you are used to hear calm and no energetic music, so your ears cant handle high volume.
OR, your source of audio is making the volume higher for you than for me on my source here.

Ive been listening at this volume for 10years, always enjoying music with energy and good bass, and yes, i have already done medical exam to test my hearing, its normal, i swear to you.

By the way something important:
As i stated too, i have Magni Heresy, had Magni 3+, and those 2 produced much more high volume than A30Pro at the same % volume , to the point i could not keep listening to those 2 amps at that volume aswell as you told me now. But mostly because of their Trbles, piercing and hurting.

 

[masterdragon]

Just out of interest and if you havent already packed it up to return- does that part of that track do it at any volume level? Or just in high gain, high volume? Is the other music that triggers it of a similar nature?

Given the nature of the music I would agree with others, likely DC protection kicking in for a particular beat/ pulse. Now whether it should or not is a different question and one for Topping to answer. Definitely needs sending back anyway.

only at High Gain, over 65% of the volume knob (really not that loud as IAtaman seems to suffer).
There are some other music that triggers it too, and now i can see something in common with them: they all have variations of bass more than the songs that does not trigger the issue.

If so, failure of a design then, should not happen in my opinion. And as i stated above:

my Magni Heresy produce the same amount of volume (even higher if i put it 100% only for test) and doesn't trigger anything in any music.
The only reason i wanted something better than magni Heresy but with the same capability of volume is one: Magni Heresy Treble terrible piercing like a Knife in your ears. But the bass is amazing, same as topping A30Pro (the A30Pro has the same bass as Heresy + Sweet Treble, if wasnt for this problem, again, i would be really satisfied).

 

[staticV3]

There are some other music that triggers it too, and now i can see something in common with them: they all have variations of bass more than the songs that does not trigger the issue.

If so, failure of a design then, should not happen in my opinion. And as i stated above:

If your music has DC content in it that triggers the Amp's DC protection, then that's not a design failure. The Amp is doing what it's supposed to (protecting your headphones) and your tracks are just shoddily mastered.

You can high pass your music via EQ to get rid of DC and that will most likely resolve your issues.

Take it up with the artists or mastering engineers who aren't doing their job, not with Topping who are just trying to prevent damage.

 

[unpluggged]

Magni Heresy Treble terrible piercing like a Knife in your ears

No wonder if you drive it to clipping with a DC or square wave signal. That's how high-frequency harmonics sound, you know.

 

[IAtaman]

If so, failure of a design then, should not happen in my opinion. And as i stated above:

If this is your track, or of someone you know, ask them to put it through a highpass filter and upload it again.

 

[IAtaman]

No wonder if you drive it to clipping with a DC or square wave signal. That's how high-frequency harmonics sound, you know.

I saw you posted an Audacity waveform. Could you check the spectrum to see how low it goes if not too much trouble please.
I might be wrong, but I don't think it is going all the way to DC.

 

[unpluggged]

I might be wrong, but I don't think it is going all the way to DC.

I was hoping it does not, too

 

[usern]

OR, your source of audio is making the volume higher for you than for me on my source here.

If your source is motherboard green colored output, then yes, your source is very likely way below 2V. I've experienced this with motherboards - they output lower volume signal than DACs with 2V RCA output. You will get most loudness out of A30pro paired with a 4V DAC and Magni Heresy most likely will indeed sound louder with motherboard source because it's meant for RCA DACs.

 

[masterdragon]

If your source is motherboard green colored output, then yes, your source is very likely way below 2V. I've experienced this with motherboards - they output lower volume signal than DACs with 2V RCA output. You will get most loudness out of A30pro paired with a 4V DAC and Magni Heresy most likely will indeed sound louder with motherboard source because it's meant for RCA DACs.

You made me think of trying to use my heresy as pre-amp for the a30pro, is it wise to do?