HM-801 Balanced Amplifier Module
Jul 28, 2011 at 11:29 PM Thread Starter Post #1 of 118

Nankai

Sponsor: HiFiMAN
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Order Link:
 
http://www.head-direct.com/product_detail.php?p=107
 
Balanced amp card finally finished. It has an independent TRRS balanced 3.5mm output. The 3.5mm mini jack on HM-801 body is still full functional and provide imbalanced output. We provide a TRRS cable for our HE series headphones as an accessory. We will sell spare TRRS connector and TRRS cable for UE type headphones in the near future.
 
 
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Jul 31, 2011 at 1:07 AM Post #3 of 118
How much battery life can we expect with the balance amp compared to the stock amp?
 
Aug 29, 2011 at 8:32 PM Post #7 of 118
I have received the promised evaluation loaner balanced GanQi amp module upgrade kit for the HM-801 in a nice, separate presentation case.  I'm calling it a kit, because it includes not only the amp card, but a variety of TRRS adapters, plugs and even a balanced HE-xxx series 3.5mm TRRS replacement cable.  I will be able to test that with the pair of HE-300s also received the same day, in fact, the new cable will probably be a welcome improvement over its stock cable.
 
The following quick iPhone shots show the package, as well as the easy, straightforward installation steps of the module into the GanQi bay of the DAP.  Luckily, I also received a custom Eclipse TRRS-terminated 48" OM cable for my JH13 Pros, as shown below.
 
I will post a review and proper DSLR pictures once the obligatory burn-in has been completed, but the new module worked as advertised, and with the newly released Diana Krall "The Girl In The Other Room" 24/96 high-rez album, its sound was already impressive.  The module's gain has been tuned to accommodate full-sized cans such as the HE-300s and 500s as well--which explains the provided cable--yet, I was able to detect no hiss with the JH13 Pros.  There has been, however, a very slight overdrive at zero volume level, where I could barely register the current tracks playing softly in the background.  This is not an issue at all for me, just noting it for the sake of completeness, at least as far as initial impressions go.  Any kind of hiss with sensitive IEMs--as the v1 versions of the ST amp modules had--would have been the worst case scenario for me, since I do most of my portable listening with them, as opposed to full-size or portable cans.  But that is not the case at all, and I would wager this won't be
 
The metal cover perfectly fits in the original's place, and the bump-out TRRS housing--a nice and necessary touch, since modifying the HM-801 chassis would have been a nonstarter for many obvious reasons--has been manufactured precisely to accommodate the new balanced output capability.  There was no need to refer to the included installation manual at all, the process should be wholly intuitive to any existing HM-801 owners who previously replaced the standard amp module in their devices.
 
More impressions will be posted later, once I had a chance to complete the burn-in process.  I admit I've been neglecting the HM-801 recently due to my other audio adventures, however, the new amp module has definitely rekindled my interest to find out just how far the platform has advanced with this long awaited, new feature.  As you could tell, I'm a big fan of balanced headphones and systems even in the portable form factor.  The balanced HM-801 should be an interesting listening experience, especially those who own HifiMAN HE series headphones, such as the HE-500s, which respond well to balanced, high-quality amplification from a high-resolution source, especially in the aspects of instrument separation and sound stage enhancements.
 

 
Aug 30, 2011 at 8:51 AM Post #9 of 118


Quote:
Thanks for the pics, I really want to get this module but will have to wait till I get the moola! What op-amp is being used? Would love to hear how it drives the HE300 and HE500, thanks.


 
Not sure about the chipset.  I will be able to give impressions with the HE-300s, but my HE-500s are being modded by Whiplash Audio, which involves hardwiring it with an XLR4 terminated wire and I do not have the appropriate balanced adapter to use.  The amp module has plenty of power, so it should drive both of them with authority.
 
Aug 30, 2011 at 12:30 PM Post #10 of 118
Those opamps are four OPA627 + BUF634. They sound excellent with HE300 and RE272.
 
Aug 30, 2011 at 9:56 PM Post #11 of 118
I really hate you guys! 
very_evil_smiley.gif

 
Sep 7, 2011 at 5:14 AM Post #12 of 118
Never mind the specs and all that as I trust Fang still knows what he's doing, so have ordered mine.
smile.gif
 I intend to use it with a pair of 650s, and will modify the cable to balanced myself.
 
I just hope it works properly with my early edition 801...
 
Sep 7, 2011 at 3:17 PM Post #13 of 118


Quote:
Never mind the specs and all that as I trust Fang still knows what he's doing, so have ordered mine.
smile.gif
 I intend to use it with a pair of 650s, and will modify the cable to balanced myself.
 
I just hope it works properly with my early edition 801...



So far so good with my evaluation unit.  They included a TRRS connector to determinate at least one pair of HPs, which is neat.  I would make sure you have the latest firmware installed on your unit just to be on the safe side.
 
I think you'll be pleased with the SQ.  Out of the three amp module choices, this one is my preferred module but I'm biased towards fully balanced, high-resolution systems of all shapes and sizes.
 
Sep 7, 2011 at 4:12 PM Post #14 of 118
and so we have yet another balanced portable headphone  'standard' this is truly ridiculous. sorry fang, i know i should be happy as a cable guy that i have yet another type of cable to sell, but as a consumer i think this fracturing of the standard is the worst case scenario that i predicted well over a year ago. the consumer loses, how many different balanced cables have you got for your 13's for exactly the same purpose now warp? 4? 5?
 
Sep 7, 2011 at 4:28 PM Post #15 of 118
sorry for what seems like too much angst above, but i encouraged discourse on this right at the beginning as soon as 2 'standards' had emerged with other companies talking of upcoming designs using different connectors. nobody even noticed or entered into the conversation. is this really acceptable for everyone? is every device going to need its own cable? having just had my 13's replaced after the socket on them died (its a bit vulnerable imo) and i know i'm not alone there, i'm surprised nobody else is saying anything. there is no reason that we even need a different connector for balanced or single ended, a 4 conductor cable for an upgrade cable is standard and even preferred.
 
the aim of this is not to criticize, but to prompt conversation again, i really think this issue needs to be addressed
 

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