I'll post my findings once I get the package today.  I'm pretty confident there will be a Rockbox (RB) firmware for the HM-700. Give it another 3-6 months for a release. It may not work 100% as I've read one of the biggest headaches is to write and compile the appropriate code for every physical button functionality.  However, from the images I've seen of the stock firmware, I would think it would be easier to develop a RB firmware. Also, the HM-700 doesn't have a USB DAC so that would make a simpler RB build, but I can see things getting a little tricky when using non-balanced iems' with that funny looking adapter that plugs into the HM-700 USB port.

alpha421 said:

  I'll post my findings once I get the package today.  I'm pretty confident there will be a Rockbox (RB) firmware for the HM-700. Give it another 3-6 months for a release. It may not work 100% as I've read one of the biggest headaches is to write and compile the appropriate code for every physical button functionality.  However, from the images I've seen of the stock firmware, I would think it would be easier to develop a RB firmware. Also, the HM-700 doesn't have a USB DAC so that would make a simpler RB build, but I can see things getting a little tricky when using non-balanced iems' with that funny looking adapter that plugs into the HM-700 USB port.

Click to expand...

Yeah, that's what I'm thinking too.  The adapter is kind of confusing, but still makes sense to a degree...I suspect it may be for grounding to a single amp section using the USB port, then the left/right channels via the TRS plug are only utilizing that one amp if that makes sense.  I feel like it would've been better for the design to put the two plugs on the same side though, because that adapter looks awkward.  I'm sure some may rig up a DIY solution that is a bit more compact, perhaps with an angled USB plug.  At this point I'm pretty much committed to just using the RE-400B and possibly one of the other balanced HiFiMan IEMs with this player, but for those who have a collection of non-balanced IEMs this could be cumbersome.  Still, not a bad compromise given the price.

modulor said:

  Yeah, I'm planning on getting one soon due to all the praise...word on the street is that the HM700 is capable of being rockboxed, assuming the dev team adopts the player.  Of course I'm mostly interested in SQ with the RE-400 and the player looks slick, but I'm a bit accustomed to Rockbox on my Clip+ so I'm holding out hope!

Click to expand...

I'd be a BIG fan of Rockboxing it. Rockbox is one of the big reasons I'm resurrecting my iPod Video.

So, I received my  HM-700/RE-400B combo today directly from Head-Direct.  I appreciate the fast shipping (3 days) from the date I placed my order.  Here are the contents from the box and identified from left to right in the picture below:
 
Velvet storage pouch, TRRS to TRS adapter cable, TRRS/USB cable, USB mini cable, RE-400B tips and filters, quality check card, HifiMAN business card, HM-700, manual, workout arm band case (which I'll never use), and the RE-400B earphones with removable cable clip.
 

 
The storage box is the same size and dimension used with the HM-601/slim.  The velvet lined padded and molded cutouts are a nice touch.  
 
Current HM-700 firmware build: 1.09, and based on my subsequent impressions, I sure hope there will be future updates until a stable Rockbox build is available.
 
My past experience with a portable balance DAP was with my previously owned Hifi ET MA8 with balanced card that has AD797 opamp sets for each channel. At the time of its ownership, I paired with the HifiMan RE-ZERO. The biggest difference for me going balanced versus single ended was the soundstage width. It's like changing from 4:3 ratio to 16.9 aspect ratio. It sounds airy and dynamic. Overall, the initial experience for me was a big "WOW" until I listened to some Jazz tracks.  Going back to the TV analogy, a few Miles Davis tracks yielded a "stretched" presentation. It didn't have that intimate or natural sensation like most Jazz venues I use to attend. However, like any brain burn in phenomenon, listen to something long enough and many times over, eventually it becomes fine/acceptable/normal and may progress to great. I digress...onto the HM-700/RE-400B.
 
For those wanting to know the what ifs' when plugging the RE-400B and other iem/ciem into the HM-700 or other sources, here's a very quick rundown of what to expect based on similar chain components with average volume level between 19-20 out of 40 max, EQ set to Normal:
 

1. Non-balanced CIEM-->HM-700 = Sounds great (supports TRS as told by ClieOS)
2. RE-400B-->HM-700 = Sounds really great
3. RE-400B-->Sansa Clip Zip = Sound in only left channel
4. RE-400B/TRRS to TRS adapter-->Sansa Clip Zip = Sounds great
5. AS2/Silver Dragon TRRS balanced-->HM-700 = Sounds really great, but with hiss
6. AS2/Silver Dragon TRRS balanced and TRRS/USB adapter-->HM-700 = Sounds really great, no hiss
7. Grado RS2-->HM-700 =  Surprisingly good

​
Here's a quick summary of the HM-700:

1. The size close to that of the Apple Mini 1st/2nd Gen iPod with the aluminum chassis and pastel colors.
2. No gapless support with current firmware as there is about 2 second gap between tracks.
3. My collection is FLAC, and it ONLY supports 16/44.  I copied over some 24/96 HD tracks and the player recognized the folder and files, but the player responds with an unsupported format message that for what ever reason took 10 seconds to unfreeze.
4. There are preset EQ (normal - default, rock, pop, classic, jazz, electronic, full bass) AND custom EQ (50, 200, 1K, 3K, 4K) vertical bands.
5. It can be played while charging.  I have a portable battery pack with USB ports and it charged up the HM-700 just fine.

 
Minor issues and personal/pointless rants:

1. There's no way to change the font size.  I think it's WAY too big.  The font size on my previously owned HifiMAN DAPs (HM-601/601LE/602/801) were much better.
2. Yes, I think the headphone out should be either at the bottom or the top of the player.  At second best, its position should be placed on the upper right, not the lower left as it makes holder the player a little awkward.
3. The Pause/Play button is on the right arrow pad.  I would love to have it be the middle button in place of power/lock key functions. I was looking at my Clip Zip and thought how Sansa pretty much nailed it IMO with button placement, functionality, and usability; or perhaps over the years I've gotten use to the logical layout.

 
So how does the RE-400B/HM-700 sound together? 
 
I concur with other owners that the two combination sounds very, very nice. They compliment each other perfectly as if they were made for each other as indicated by their combo offering.  Finally, I get stock tips that actually fits without seal issues.  I want do back flips, but I can't. None of the tips from my previously owned HifiMan iems' (RE0, RE-ZERO, RE-252, RE-272, RE-400, RE-600) fit me, so I had to resort to the insanely priced Ortofon or UE Triplefi10 silicon tips. A pair of included Ortofon like tips are making my ears and temperament relatively happy.
 
I won't go too much into the RE-400/B on how balanced and insanely good it sounds for $99 as there's plenty of reviews on them, but I'm very impressed how it sounds with the HM-700 - smooth and balanced like this cold, tall glass of Guinness I'm drinking while typing this review, so pardon the typos.
 
Regarding that funny TRRS/USB adapter. It works as intended to reduce hiss. I heard zero hiss with the RE-400B, but with my AS-2/balanced Silver Dragon, I heard a moderate level of constant hiss with no music, on pause, or within that 2 second gap between tracks.  I'm not too bothered by the hiss, so I won't be using the adapter. It kind of reminds of the hiss with active noise canceling headphones/iems. It's nice that HifiMAN provided a solution despite being far from elegant, but it gets the job done. 
 
I don't know what Fang's strategy is with the HM-700/RE-400B combo, but if it's to demonstrate that you can get really great sound without buying anything else with an added taste for balance at a bargain price of $249, I think he succeeded.  I'm sure he has his fingers crossed for owners to move on up to his TOTL DAPs (HM-802/901).  In due time, I will.  Until then, I hope for meaningful firmware updates, and the folks at Rockbox working their magic to create a stable build for the excellent sounding HM-700.

Thank you very much for the review,
but the gapless for me is an essential function.
I was very tempted to purchase, but I'll wait until this function is made operative with new firmware releases or via rockbox (if possible).
 
 
Quote:

alpha421 said:

1. No gapless support with current firmware as there is about 2 second gap between tracks.

Click to expand...

i am a BIG hifiman , i own(ed) re-zero/252/262/272/400 , and this looks terrific especially for the price and i would have bought it
 
BUT
 
no gapless on the HM700 = deal breaker.
 
 
the lack of a sd card slot is also a big minus , but i could live wihtout one (maybe)
 
when the gapless function is added , this will be definitely in my sights.
 
nevertheless , glad to see Dr Fang and his team continuing to prduce stellar products with such competitive prices.

 

proedros said:

  i am a BIG hifiman , i own(ed) re-zero/252/262/272/400 , and this looks terrific especially for the price and i would have bought it
 
BUT
 
no gapless on the HM700 = deal breaker.
 
 
the lack of a sd card slot is also a big minus , but i could live wihtout one (maybe)
 
when the gapless function is added , this will be definitely in my sights.
 
nevertheless , glad to see Dr Fang and his team continuing to prduce stellar products with such competitive prices.

 

Click to expand...

After giving it more thought, I may be in the same boat but we'll see.  I think I could live with gapless playback for some time until new firmware or Rockbox comes out, but the lack of SD expansion slot is kind of a bummer.  It's still a tremendous value, no doubt.

I do not understand what the reason for which the gapless function is never taken into consideration as a standard in the new dap.
What is so hard to implement this feature?

I received my HM700 RE400B Bundle yesterday. Even with FLAC I don't experience this "2 second" gap. It's actually not even close. Timing it it is between .1 and .4 seconds on various tracks, usually being closer to .1. 
 
Maybe it's tagging? It was hard for me to get tagging for FLAC to work flawlessly on my HM601 (mp3tag's tags weren't recognized) but on most albums, I swear it's almost gapless for me. Going to try DSOTM now to see. Will report back. Also will check my firmware but I'm sure it's the same as everyone else's.
 
*edit: Yep, 1.09. What did you all use to encode? I usually was using DB Poweramp but the tags weren't showing on my 601 (and only my 601) so I've been using XLD on my Mac and Kid3 for re-tagging as needed because nothing else I had would work. And yep, even on Pink Floyd DSOTM I am getting literally .1 sec or less of silence. There was no pop or click between Speak To Me and Breath.
 
Now I want to know why.

d rob said:

   There was no pop or click between Speak To Me and Breath.
 
Now I want to know why.

Click to expand...

 
in some editions, (for example the remastered ed., 1994 http://www.discogs.com/Pink-Floyd-The-Dark-Side-Of-The-Moon/release/825351), 'Speak to Me' and 'Breathe' are a single audio track. 

unkle said:

in some editions, (for example the remastered ed., 1994 http://www.discogs.com/Pink-Floyd-The-Dark-Side-Of-The-Moon/release/825351), 'Speak to Me' and 'Breathe' are a single audio track. 

Click to expand...

This is the MSFL mastering. It is indeed two tracks. Its not going to please a purist as there is a separation but it is considerably better than other non gapless players I own.

So no one actually bought the hm802? I am not that interested in the HM700 , I know there are some hearing impressions already on the hm802 , but no one seems to actually buy it?

Just received my 'bundle' today too.. I agree with D Robb concerning DSOTM.  I think a .1 sec gap is being generous.. it's virtually gapless for all intents an purposes.  I can't complain.  Will put up some impressions after burn-in, but 2 things out of the box: 1) soundstage - wow.. very wide and 3 dimensional, 2) power - the DAP drives the 400B's with authority and slam.  Very pleased and impressed so far.

Anybody who want to rockbox HM700, we will try our best to help. Sigma-tel 3770 controller chip is rockbox friendly. Please contact fang@hifiman.com.
 
Fang

Dr. Fang, you just might have saved a return.  After spending a few days with the HM-700, and despite how great it sounds, the stock firmware navigation and features/functions started to become a killer (in a bad way) for me.  Email en route.