It might be a stretch, but if any of you S680 owners happened to pick up a SanDisk Clip Sport, if you could evaluate if it's as good as a source as the Sansa line that would be cool. I have one and it sounds fine on my FXD 80s, but I don't a lot of experience so no good reference points lol.

Selling my 680s. PM me if interested.

Yes, please let us know how they compare.
 
My S680 is not fully burned in yet. But I can tell they do sound different than the S400.
 
So far, I wouldn't say that the S680 qualifies as a refinement of the S400's sound. Rather, they are different enough to have their own identities.
 
I'm flipflopping on which one I like better. First it was S680. But no, it was S400 when I tried those again. But last night I tried both on my Schiit Vali amp, and the S680 was preferable.
 
So I'm glad to have both.

like all JVC CNT products I already own I believe they need considerable break in to reach their full potential. like over 500+hrs

Mine are nicely broken in and shipped for $50.

So I did get myself a pair of Creative Aurvana Live! 2s. Yeah, they sound pretty great right out of the box.

This coincided with what I think is a middle period of burn in for my S680s - they sound neither here nor there. They're OK, but not very engaging at all. I recall them having a captivating quality shortly after I got them, but that seems to have gone missing. I hope all this gets organized and the good qualities return after more burn in.

For now, though, the Creatives are sounding sweet. Better than the S680 at this time. Of course, they did cost almost twice as much as the S680.

When you'll hear that hard punching bass, you'll you're there.

Hey guys, I purchased the HA-S680 from another headfi user that had already done 50 hours of burn in with the wav file, 50 hours with their own songs.
 
I've spent 2 days (maybe 6 hours total) breaking in my brain to get used to the sound, and wow.. I like these a lot.  I'm ready to give my S400s away. 
 
These do not necessarily have the same booming bass that the S400s have, but the difference in clarity at all levels far outweighs the difference in boomyness.  They still do have quite a bit of bass, maybe not to IEM levels of say the Pistons, but the overall quality of sound is superior to anything I own currently.
 
I don't have any high-end gear so you can take this with a grain of salt, but I would like to say holy crap, the soundstage is unbelievable. 

ebrian said:

  Hey guys, I purchased the HA-S680 from another headfi user that had already done 50 hours of burn in with the wav file, 50 hours with their own songs.
 
I've spent 2 days (maybe 6 hours total) breaking in my brain to get used to the sound, and wow.. I like these a lot.  I'm ready to give my S400s away. 
 
These do not necessarily have the same booming bass that the S400s have, but the difference in clarity at all levels far outweighs the difference in boomyness.  They still do have quite a bit of bass, maybe not to IEM levels of say the Pistons, but the overall quality of sound is superior to anything I own currently.
 
I don't have any high-end gear so you can take this with a grain of salt, but I would like to say holy crap, the soundstage is unbelievable. 

Click to expand...

 
Glad the brain burn-in worked for you, people often overlook it.
Do you mind posting a review here:  http://www.head-fi.org/products/jvc-ha-s680-over-ear-headphones ?
 
I love Pistons' bass, but sometime it's just too much. S680 has a perfect sub-bass boost, that doesn't bleed into the mids.

Just came in! Less than 2 weeks from Japan thru amazon. Under $60 delivered from Ace Japan. 1st impressions are better than my S400s from memory. I will have to compare them later tonight when I get home.

Wow. These 680s are such good value. Any noob should be impressed with these from the start. Props to Ben F for staying so vigilant about these. I'm really liking mine. And they only have less than 10 hours on em.
In my few hours I have to say these are showing much promise.

This is for the guy that wanted to know the difference between the 680 and 500
S680 w/ <10hrs
S500 taped ports AKG 518 pads

My S500s are(were) my personal favorite portable. The accuracy, timbre, signature, bass, non fatiguing, light weight, efficiency, volume, and looks were all I could ever want. Or so I thought.....

VS S500:
I immediately recognized the 680s have a bigger stage. The Highs are brighter on the 680s. It gives Percussion more presence and air. It helps expand the stage. The highs on the S500 are detailed and non fatiguing but sounded rolled-off compared to the 680s.
The mids are good on both and hard to spot much difference in timbre but the S500 sounded a bit fuller from the mids on down The 680s mids were just a tad behind. The S500 could be described as tilted towards the bass and the 680s towards the highs. The sub bass on the 680s isn't quite as strong as my modded S500 but the 680s still have a respectable amount. Think S500 is to a 12" sub and S680 has an 8". Hopefully more burn in will help.

The S500s were once my champion portables but in the short time with the 680s the added stage and highs have won me over my old favorite S500s. Like many, the only complaint I had with the S500 was its lack of stage. The 680s have answered and showed me I can have better highs as well.

I've owned the 500 and had a great bass and sub-bass impact!
I'm sorry to learn that the 680 from this point of view are lacking ...
Make a few more hours of burn-in and let us know something ... even my top 500 had a few bass...

musubi1000 said:

...
VS S500:
I immediately recognized the 680s have a bigger stage. The Highs are brighter on the 680s. It gives Percussion more presence and air. It helps expand the stage. The highs on the S500 are detailed and non fatiguing but sounded rolled-off compared to the 680s.
The mids are good on both and hard to spot much difference in timbre but the S500 sounded a bit fuller from the mids on down The 680s mids were just a tad behind. The S500 could be described as tilted towards the bass and the 680s towards the highs. The sub bass on the 680s isn't quite as strong as my modded S500 but the 680s still have a respectable amount. Think S500 is to a 12" sub and S680 has an 8". Hopefully more burn in will help.

The S500s were once my champion portables but in the short time with the 680s the added stage and highs have won me over my old favorite S500s. Like many, the only complaint I had with the S500 was its lack of stage. The 680s have answered and showed me I can have better highs as well.

Click to expand...

Keep burning them, and the sub-bass will step in, while mid-bass will come down a little, causing mids to come forward too.
How do you find S680 vs S500 comfort-wise?

OK, so exactly how long needed to burn in before they sound good?
 
I probably have 70-90 hours on mine so far. Currently much muddier than they've been since the start. Almost unlistenable right now.
 
At the very start, they sounded really promising just 10 minutes in. Nice focus on vocals and wide soundstage, but obviously new and unbalanced.
 
Currently, they are the worst I've heard them sound.
 
If some picked these up now and took that as how these phones are supposed to sound, they would walk away and never come back.
 
I do expect them to get better. I was under the impression that these new generation carbon nano-tube drivers didn't take that long to settle, though.
 
From what I'm hearing, they take longer than I thought.

benf said:

Keep burning them, and the sub-bass will step in, while mid-bass will come down a little, causing mids to come forward too.
How do you find S680 vs S500 comfort-wise?

Click to expand...

The 680s are very comfortable. I never had a problem w/ the 400/500.
In the short time I've had them the bass has picked up and is less sloppy now.