[manveru]

I was sitting back in a chair listening to music on my new AD2000s through the Matrix Cube DAC. When I stood up, I heard this loud noise come out of the left side of the headphones. At first, I thought it was the headband creaking or something, but it seemed too loud to be that. It sounds like a series of harsh digital clicks. I sat back down the way I had been sitting, stood back up, and it happened again, only this time the sound completely cut out afterwards! I nearly had a heart attack, thinking my brand new headphones were busted. I went up to the computer and noticed the song had been paused. I played it from the beginning and all was back to normal. Puzzled, I started trying to reproduce this phenomenon, and noticed that on the times when the music would cut out, the "signal" LED on the Cube would flicker on and off in sync with the clicky noises, go dead for a second, and then come back. If I went and restarted playing a song, everything would work normally. After doing various experiments using different combinations of headphones and sources, I have determined that the Cube is the variable whence this strange occurrence originates. Furthermore, it only happens under these very specific circumstances:
 
1. It only happens if the AD2000 are plugged into the Cube, and not with any other headphones.
2. It only happens if I stand up coming from a slouching or leaned back position. For example, if I'm sitting forward in the chair and stand up it doesn't happen. I also tried moving my head around in different ways while standing and sitting without anything happening.
 
This is just extremely weird. Any one have an idea as to what the heck is going on? 

 

[NA Blur]

This is the third case of this happening with a completely different setup.  Do you think it could be static build up when you move?
 
Another issue with some DACs is their ability to sync with low compression files.  It is hard to say if it is the DAC or the way a PC processes through the USB port in my case, but when this happens to me I lose the song or it skips.  I do not hear the loud crackle, but I lose sync with the track and it cuts out.  This only happens to me with uncompressed music playing through Foobar2000.  It never occurs while listening to compressed files even at 328 kbps.
 
Try playing a compressed version of the song and see if it happens.

 

[manveru]

 
Quote:

This is the third case of this happening with a completely different setup.  Do you think it could be static build up when you move?

Yeah, I was sort of thinking that. It's awfully strange.
 
 

Another issue with some DACs is their ability to sync with low compression files.  It is hard to say if it is the DAC or the way a PC processes through the USB port in my case, but when this happens to me I lose the song or it skips.  I do not hear the loud crackle, but I lose sync with the track and it cuts out.  This only happens to me with uncompressed music playing through Foobar2000.  It never occurs while listening to compressed files even at 328 kbps.
 
Try playing a compressed version of the song and see if it happens.

 
When does this happen to you? Does it happen just randomly or is it triggered by a physical event? Do you know if it only happens with certain headphones? I'll try listening to some compressed files later to see what happens. The crackling is what really bothers me more than anything. I just hope nothing gets damaged.

 

[NA Blur]

The loud sound never happens with me, but I have read three independent cases now here on head-fi describing exactly this issue.
 
Conditions:
 
Listening to music and then all of a sudden loud pops or crackles are head usually from one channel
 
What I hear with my setup is when I play a CD rip in .wav my m903 will hiccup sometimes and skip just like it would as if the CD had a scratch on it.  I retest the track and it does it at different times.  I suspect Windows more than anything.  It is like the audio buffer fills up or can no longer buffer so it simply drops part of the track to compensate.
 
I imagine different DAC setups have multiple ways of dealing with this.  Perhaps my DAC simply drops the signal to zero and yours creates a popping sound.
 
Would you answer these questions please?
 
1.)  What compression if any are you using on your mp3 / wav / aac / FLAC files when you hear this?
 
2.)  What player are you using like Foobar, iTunes
 
3.)  Does moving the DAC unit around while you listen to music present the noise issue?

 

[manveru]

Huh, interesting.
 
Quote:

Would you answer these questions please?
 
1.)  What compression if any are you using on your mp3 / wav / aac / FLAC files when you hear this?
 
2.)  What player are you using like Foobar, iTunes
 
3.)  Does moving the DAC unit around while you listen to music present the noise issue?

1) I was listening to FLAC at the time this happened. I use level 8 compression on the files I did, but many are also not my rips.
 
2) I'm actually using Linux. My music player is Audacious.
 
3) I'll try this when I get home tonight.

 

[manveru]

I was unable to reproduce the effect by moving the DAC around. I'm now pretty sure it is static electricity. I've never had software problems before. Just now it happened when I had the Cube connected to an external amp and then listened through that. This time it didn't effect the DAC at all, but I just heard the crackling from the headphones. I think I can actually feel it shocking my ear too. This seems to prove that it's actually the AD2000s causing the issue, but oddly enough, if they are connected to my Cowon this doesn't happen at all :\

 

[tk3]

IIRC some of the AT headphones have some problem with the design of the cable, AT Japan disclosed that in a news post on their Japanese website, the A2000 was one of them.
They seem to function without problem in general, but the DAC might have some sort of effect on them that causes them to do that crackling.

 

[manveru]

Thanks for the info tk3. Were there ever any reports of headphones being damaged because of this issue? That's the only thing that worries me.
 
So I guess their conductivity is also somehow effected by what they're plugged into... I guess I'll have to use my portable player for the time being. Right now the chair I'm using is covered in a kind of soft fuzzy material. I'll try getting something like leather that hopefully won't be as staticy.

 

[tk3]

I don't think there were any problems of that sort, at least I've never read about it on these forums.

 

[NA Blur]

The shielding of the wiring or the lack of an adequate ground would cause the "shock" and thus noise issue.  Because one setup has it and another does not tends toward the shielding or ground.

 

[Sil3nce]

I doubt it's the ad2000.
It's happened to me as well, albeit with electrostatic cans.
 

 

[manveru]

 
Quote:

The shielding of the wiring or the lack of an adequate ground would cause the "shock" and thus noise issue.  Because one setup has it and another does not tends toward the shielding or ground.

I only have a rudimentary understanding of electronics, but I figured it might be related something like that.
 


Quote:

I doubt it's the ad2000.
It's happened to me as well, albeit with electrostatic cans.

Well, they didn't create the problem, but I think they may have "allowed" it to happen, so to speak. I've switched to a leather chair and as I suspected this problem is gone, thankfully.

 

[Mishalex]

I have had a similiar issue with the iBasso D7 "Sidewinder," while using AKG's new K550 headphones.  In my case, I'm certain its not the headphones, as they work fine with my FiiO E7+E9 combo.  NA Blur has responded and directed me to this thread.  After discussion with NA Blur, I have become reasonably convinced that the D7 either wasn't grounded properly or had problems with internal static build-up due to lack of proper shielding around the internal connections.  Unfortunately, I couldn't open the device up to take a look, as I was afraid of voiding the warranty, and I'm also not the most handy with electronics myself (I would have had to ask an engineer friend of mine to take a quick look).  Comically, it sounds like the additional static build-up from your other chair was enough to cause this problem.  I'm glad you seemed to have resolved your issue, though.  Hopefully, it won't return.

 

[Headzone]

Did you have a cellphone near the DAC/Amp?

 

[Mishalex]

Nope.  In my case, the interference was not cellphone related. (Not sure if you were asking me or manveru).