[K.T.]

Interesting report on the comparison between 90+ burn in and new. Don't know what to make of it. Probably would have a better idea if you did take note of how both sounded compared to each other before burning in the one pair.
 
For me, it seemed to take a LOT of burn in before they sounded good. I don't remember now, it's been a while since I've checked this thread, but I recall it was a very sudden change, and that it was something with more hours than you've already put on yours.
 
Still, I have a love/hate relationship with these cans. The last time I used them, it was in direct comparison to a pair of Audio Technica M50s and a pair of Logitech UE6000s. They were all driven by a portable FiiO E12DIY with OPA627 chips and BUF634 buffers.
 
The M50s sounded best, warm and communicative, with decent (but characteristically slightly flabby/loose) bass.
 
The UE6000 were alright, but more clinical and slightly lifeless, and didn't breathe as much as the M50s.
 
The S680 were horribly muffled and veiled in comparison. The did not sound awful, but so muffled in comparison to the other two.
 
Odd, because I've heard the S680 sound warm but open and lucid. Yet other times they sound really muffled.
 
Now I haven't really played the S680 for some time, so is it possible that these tighten up with disuse and need a little time to loosen up after sitting around? Crazy? Just a thought.
 
So I don't know what to make of it. Sometimes the cans surprise me with delightful sound, other times I feel like I should sell them.

 

[hybrid35]

I might order the Sabre DAC for this. Does anyone think there is a difference between the asynchronous version and regular version for these headphones?

 

[BenF]

Nothing you could tell apart in a blind A/B session

 

[andreamang]

Too many conflicting opinions ...

 

[ebrian]

Weren't you considering these headphones like 2 months ago?  Talk about indecisive!  I'm gonna go out on a limb here and predict you won't be buying these.

 

[hatefulsandwich]

He's never gonna buy anything because he wants to know for sure that he'll like it before he buys it without hearing it and that he won't be charged customs.

 

[andreamang]

I ordered May 14 and are waiting to receive them ... I think that now you feel more calm ...
Bla bla bla

 

[hybrid35]

Haha regardless of the need to burn-in, these sound great. It's probably more of the brain burn-in that you need.
 
FYI I ordered through amazon and no customs were charged. They just arrived on my door and that was it.

 

[Bugo]

  Haha regardless of the need to burn-in, these sound great. It's probably more of the brain burn-in that you need.
 
FYI I ordered through amazon and no customs were charged. They just arrived on my door and that was it.

I realy think that you need to burn them in, you will notice the difference.
 
I also found that if you don't listen to them for a while, you need to burn them in again. 
 
After I didn't listen to them for about two weeks when I was away, I came back home to find
that they don't sound as good as I remembered, so I let them burn for a night and now they sound good again...

 

[hybrid35]

  I realy think that you need to burn them in, you will notice the difference.
 
I also found that if you don't listen to them for a while, you need to burn them in again. 
 
After I didn't listen to them for about two weeks when I was away, I came back home to find
that they don't sound as good as I remembered, so I let them burn for a night and now they sound good again...

 
 
Interesting. Maybe the ones I have are a new batch? They really don't sound all that different, and I have continued to burn them in for about 200+ hours already. Maybe I should up the volume more? haha

 

[BenF]

   
 
Interesting. Maybe the ones I have are a new batch? They really don't sound all that different, and I have continued to burn them in for about 200+ hours already. Maybe I should up the volume more? haha

The volume during burn-in should be above a comfortable listening level.

 

[hybrid35]

 
The volume during burn-in should be above a comfortable listening level.

 
It's definitely above comfortable, but not deafening. I kind of have a high pain tolerance.

 

[ebrian]

My understanding was that burn-in cannot be reversed.  It's not like a rubber band that gets stiff again if not stretched for a long time.  It's more like.. bending an iron bar.  It ain't going to retain shape again all by itself.

 

[K.T.]

It's interesting, this conditioning/burn-in.
 
One would think that they would stay in state after the burn-in period. But who knows?
 
On a related idea, I recall hearing an interview with the violinist Itzaac Pearlman (or was it Annie Sophie Mutter, or someone else?) who described how, if they hadn't played their concert violin for an extended while, the sound would close up and sound shut down when they played it next. The violin would need to be played a bit until the sound opened up and breathed again.
 
Now, the diaphrams of a head phone driver and a concert violin are two different things, but the concept of a diaphram tightening up or changing during period of disuse is not unheard of.
 
So who knows?

 

[hybrid35]

Someone want to volunteer to do a scientific experiment on carbon nanotube burn-in flex? S400's will do!

And then maybe see the retention period after the dissection.