[Sambaaa]

Hi, I'm a Chuwi V99 quad core owner. My tablet has a sound issue which probably many of you have already heard about.
If you don't know what it is here I uploaded a video and an audio recording of the problem:
Video--> www .4shared.com/video/00MBGiUw/Mobile_Video_130202_141154.html
Audio--> www .4shared.com/music/8KvGgipq/Memo.html

Each time I touch an icon or home button, back button an so on, after the standard click sounds starts a strange interference sound which, after 2-3 seconds, leads to a "clack".
In the video you can't hear the interference but only the "clack" 2 seconds after the click (not so easy to hear in the video actually).
In the .m4a file you can hear just the audio recordered while using the tablet. You will hear a first click caused by me clicking on icons/buttons, the following interference created in the camera side speaker and the final "clack". All these 3 steps repeated many times. In the audio you can ear pretty well both (interference and clack), in the video it has been impossible.

Anyways the real central point of the matter is that I have been told by Eternal that this issue is an hardware problem that ANY A31 TABLET HAS.
They told me that they tested each Onda V972, Ainol NOVO 9 Spark, Freelander PD80, CHUWI V99 quad, ... and they all have this issue in ANY unit (not just a few defective) and that the "pop" sound may just be more or less loud in different units.

Is it true that any A31 tablet has this problem? Could you please tell me if you have this issue or not and what A31 tablet do you have?

(To quickly test it, enable click sound and then click on any app/icon to hear the sound produced)

Thank you!

This post has been edited by Sambaaa: 08 February 2013 - 10:47 AM

[fldc]

It could just as well be a software problem, they're all using the same Allwinner SDK.

[Sambaaa]

fldc, on 08 February 2013 - 11:42 AM, said:

It could just as well be a software problem, they're all using the same Allwinner SDK.

Yeah I still don't understand whether it is hardware or software and probably they don't know it either.
At the beginnning they told me it was just a bug that a future firmware release would have solved, but then they change their mind and wrote me this:

"I confirm to the technical sound problem it's Hardware problems , In the the motherboard line design of the circuit affect, But does not affect the normal use, and there is no other functional impact"

An hardware A31 CPU unsolvable(??) problem then. I don't know, that's what they told.

[letsfightinglove]

Sambaaa, on 08 February 2013 - 12:31 PM, said:

Yeah I still don't understand whether it is hardware or software and probably they don't know it either.
At the beginnning they told me it was just a bug that a future firmware release would have solved, but then they change their mind and wrote me this:

"I confirm to the technical sound problem it's Hardware problems , In the the motherboard line design of the circuit affect, But does not affect the normal use, and there is no other functional impact"

An hardware A31 CPU unsolvable(??) problem then. I don't know, that's what they told.

They are saying that the motherboard layout of the Chuwi V99 was poorly designed, not that it's a problem with the A31. Possibly all the current A31 tablets use similar designs, though. There's probably nothing you can do unless possibly MacGyvering some appropriate shielding inside the unit.

[Sambaaa]

letsfightinglove, on 08 February 2013 - 05:12 PM, said:

They are saying that the motherboard layout of the Chuwi V99 was poorly designed, not that it's a problem with the A31. Possibly all the current A31 tablets use similar designs, though. There's probably nothing you can do unless possibly MacGyvering some appropriate shielding inside the unit.

I don't feel ready for Macgyvering my tablet yet! maybe I'll try in the future!

Eternal opinion is as follows:
"I have tested Onda V972, NOVO9,Freelander PD80 and CHUWI V99 etc.. all A31 products all have this problems. not only this model. The difference is that the sound is big or small"
"CHUWI V99 100% have this problems, and other A31 all have this problems"
I was asking this here since I have never heard about this issue in tablet different from Chuwi and only for a small part of Chuwi v99 anyways.

[gmail90]

well i also notice some clank sound just after i press my physical home button, when entering the lock screen . only that.

Btw my device is onda v972

[Sambaaa]

gmail90, on 09 February 2013 - 12:14 AM, said:

well i also notice some clank sound just after i press my physical home button, when entering the lock screen . only that.

Btw my device is onda v972

Thank you for your answer. Does it happen only in that case? No strange sound with click sound enabled when you click on any icon?

[fldc]

gmail90, on 09 February 2013 - 12:14 AM, said:

well i also notice some clank sound just after i press my physical home button, when entering the lock screen . only that.

Btw my device is onda v972

That sound is not coming from the speakers though.

[PocketSmiley]

Sambaaa, on 08 February 2013 - 10:35 AM, said:

Hi, I'm a Chuwi V99 quad core owner. My tablet has a sound issue which probably many of you have already heard about.
If you don't know what it is here I uploaded a video and an audio recording of the problem:
Video--> www .4shared.com/video/00MBGiUw/Mobile_Video_130202_141154.html
Audio--> www .4shared.com/music/8KvGgipq/Memo.html

Each time I touch an icon or home button, back button an so on, after the standard click sounds starts a strange interference sound which, after 2-3 seconds, leads to a "clack".
In the video you can't hear the interference but only the "clack" 2 seconds after the click (not so easy to hear in the video actually).
In the .m4a file you can hear just the audio recordered while using the tablet. You will hear a first click caused by me clicking on icons/buttons, the following interference created in the camera side speaker and the final "clack". All these 3 steps repeated many times. In the audio you can ear pretty well both (interference and clack), in the video it has been impossible.

Anyways the real central point of the matter is that I have been told by Eternal that this issue is an hardware problem that ANY A31 TABLET HAS.
They told me that they tested each Onda V972, Ainol NOVO 9 Spark, Freelander PD80, CHUWI V99 quad, ... and they all have this issue in ANY unit (not just a few defective) and that the "pop" sound may just be more or less loud in different units.

Is it true that any A31 tablet has this problem? Could you please tell me if you have this issue or not and what A31 tablet do you have?

(To quickly test it, enable click sound and then click on any app/icon to hear the sound produced)

Thank you!

I can confirm the same thing on the F9X.

Also, when watching videos or playing music, there is an intermittent crack that appears randomly after every few seconds. Right now I'm too in love with the Retina display to fault anything, but this sound problem does prevent me from using the tablet for music (videos are forgivable).

[Sambaaa]

PocketSmiley, on 25 February 2013 - 11:58 PM, said:

I can confirm the same thing on the F9X.

Also, when watching videos or playing music, there is an intermittent crack that appears randomly after every few seconds. Right now I'm too in love with the Retina display to fault anything, but this sound problem does prevent me from using the tablet for music (videos are forgivable).

Is the sound you noticed similar to the one you can hear in the video I linked? On my tablet it doesn't appear randomly but each time speakears are enabled/disabled for example by starting/stopping a video even with volume set to zero. By the way thank you for your report!

[PocketSmiley]

Sambaaa, on 27 February 2013 - 01:56 PM, said:

Is the sound you noticed similar to the one you can hear in the video I linked? On my tablet it doesn't appear randomly but each time speakears are enabled/disabled for example by starting/stopping a video even with volume set to zero. By the way thank you for your report!

Ah, so the F9X may have a different sound problem. In the video, the "clank" sound is delayed. In the F9X it comes right after, in less than a second.

The random distortion while playing music and videos is not the fault of the internal speakers; even quality headphones reproduce the distortion. It's similar to the sound coming from a sound card with latency problems. The distortion is the acceptable kind you expect from cheap speakers that do the job. But it's not the speakers.

[mohammed穆罕默德]

yes i have the same issues ... also the microphone is not good very slow .you can not use it to talk in skype or qq viber .... very slow . i have vido yuandao N90quad-coreFHD allwinner a31

[Sambaaa]

mohammed穆罕默德, on 16 March 2013 - 06:48 PM, said:

yes i have the same issues ... also the microphone is not good very slow .you can not use it to talk in skype or qq viber .... very slow . i have vido yuandao N90quad-coreFHD allwinner a31

Thank you for your report! Microphone in mine works good, no problem until now. Speakers sound level was not high enough, but it has been fixed by custom rom.

[oversc0re]

This click is obviously generated by the sound chip waking from/entering sleep mode or in other words by oscillator start of the d class amplifier. They could probably avoid this click by better output filter design but looks like they didnt care or notice.

[Sambaaa]

oversc0re, on 26 March 2013 - 06:27 PM, said:

This click is obviously generated by the sound chip waking from/entering sleep mode or in other words by oscillator start of the d class amplifier. They could probably avoid this click by better output filter design but looks like they didnt care or notice.

Yeah I think you're right. I'm not an expert about it but what you said seems perfectly reasonable. What is strange is that just a few tablets seems to have this issue or, at least, just a few tablets produce a sound loud enough to be noticed. So don't know whether it is a motherboard design mistake or a production fault or both together. Anyways it seems definetely something which cannot be fixed.