Pros: Very clean and balanced sound, tight bass, non-sibilant yet present highs, vocals are engaging, airy yet intimate soundstage, resolving, comfortable
Cons: Limited availability, intended for Japanese market.
The review thread is here: http://www.head-fi.org/t/690493/the-jvc-ha-s680-s400s-and-s500s-big-brother-is-here
JVC HA-S680 is the next generation of HA-S400 and HA-S500, with the carbon nanotube technology.
Just like them, it's not meant to be sold outside of Japan
Nevertheless, here we are!
They utilize a 40mm driver, but it's not the same driver as in S500 - it is the next generation!
Output sound pressure level: 102dB/1mW
Playback frequency: 8Hz ~ 26.000Hz
S500 is louder (106dB/1mW) and has 1 Khz less extension at the top.
I own S400, so I will be using it for comparison.
Sound Quality - upon receiving them, I gave them a short audition. They sounded nothing special, but I had good reasons to believe they would improve:
1) It took me over 200 hours to fully burn-in my S400s, and they didn't sound great until the process was finished.
2) These are Japan-only headphones, and Japanese usually keep the best stuff to themselves
3) SQ was scaling up with better sources - always a good sign.
So I started burning them with this noise:
12 hours in - Small changes here and there
24 hours in - Oh my god, did they burn in already? All the frequencies sound so much better,
especially the bass. I compared them to S400, and it became clear that there
was still a long way to go - the bass wasn't as tight and vocals weren't as emotional.
48 hours in - Now this a clearly superior headphone to S400.
Sound is balanced, similar to S400's sound signature, but the bass hits harder
(although just as tight) and the larger pads helped improve soundstage and
imaging. Instrument separation is better too. The vocals are very engaging.
72 hours in - No audible differences.
This is where I believed that this is a new improved driver, and not just an old repackaged one.
The old driver took over 200 hours to burn in, but they perfected the formula and the new one is done in 48!
There are a few significant design changes in S680 - 1) Bass ports 2) Larger pads
The bass ports are necessary for the harder hitting bass, what surprises me is that the bass is still just as tight as before, despite increase in volume. There is no leakage into the mids either.
Comfort - the larger pads increase both soundstage and comfort. For some people, especially women, these may be around-the-ear,
for me they are still on-the-ear. However, they are much more comfortable then S400, because they press on the more remote parts of the ear.
I've tried the Shure HPAEC840 pads - they are too big, may need to be modified to fit properly.
BrainWavz HM5 pads are a perfect fit, but have the same effect as on S400 - soundstage improves, but the bass becomes a little boomy. The HM5 look like they were made for S680, on S400 they looked monstrous.
Isolation - the larger pads make it better, but the bass ports make it worse. They are OK to use in an office, but not on a mass transport. Sound leakage is minimal, can be used in a library.
Overall, this is a fantastic portable closed phone, my new #1, ahead of HA-S400 and ATH-ES700.
They scale well with better equipment, but aren't hard to drive.
They also make a decent desktop speaker - I can put my NFB-11.32 on high gain and volume at 1-2PM - the sound fills the room
Price - I have bought it from White Rabbit Express for 96$ including shipping.
I've asked one of my Japanese eBay sellers to list it, and he listed all 3 models for 80$ including shipping!!!
I guess the pioneers always pay a price...
The black one is here:
The red one is here:
The white one is here:
I've bought some audiophile items from him before, he's really good.
Also, you can buy them directly from Kakaku for 65$-75$ depending on color and your location:
Other users' impressions:
The burn-in procedure:
2) Adjust the volume so that the middle noise is too loud for comfort
3) Take the headphones off, and add another 20-30% volume
4) Keep burning 24/7
5) Give it at least 48 hours
6) Once burn-in of the driver is done, please let your brain burn-in as well - it will take a few days for the brain to adjust to
the sound. At first, the brain will refuse to process the soundstage and clarity that HA-S680 can produce, but it will give in