After a long wait, the production version of the long-awaited HiFiMAN HM-602 (specs) has finally arrived. The delay has been associated with a much more elaborate preproduction testing phase and for the first time for Head-Direct, Fang has decided to release a first batch of HM-602s to the Chinese home market to gather additional feedback from a wider audience. This has resulted in some last-minute design tweaks and cleaning up the signal path of the opamp circuitry to optimize the design output and the best sound quality.
I have had a chance to briefly evaluate the preproduction version back in August during the Charlotte, NC Can Fest even. Those are documented here: http://www.head-fi.org/forum/thread/504567/hm-602-portable-music-preorder/75#post_6857526
Most of these impressions and conclusions essentially apply to the production version so I will highlight those that have changed or new altogether.
Presentation and Miscellaneous Details
As you can see from some of the photos, the HM-602’s packaging and overall presentation equals to that of its bigger brother, the HM-801, which is no mean feat at this much lower price point. I know of no other portable digital player that is presented in this kind of upscale manner, at any price and definitely adds to a very satisfying first impression.
A smaller pouch, compact AC-charger with both US-spec and Euro-spec plugs are standard, another thoughtful touch for the Global Head-Fi community and others who travel frequently overseas. Also included under hidden compartment is a USB cable for DAC or file transfer purposes as well as a cleaning cloth inserted into the pouch, which comes in handy for fingerprints.
The generous warranty terms are now detailed in a Warranty Card supplied in the box applicable to the unit’s serial number: 30-day no questions-asked return policy, 3-month replacement warranty and 12-month limited warranty parts and labor, valid only with the warranty card, assuming normal use. If you’re thinking of tinkering with this, don’t: there is an easily torn warranty sticker in place on top of the analog board, making disassembling the device impossible without voiding the warranty (guilty as charged, I couldn’t resist exploring under the hood a bit).
3.5mm HP-out: The HM-801 does not accommodate very well the Oyaide connectors, but loves the slightly thicker ViaBlue jack. The HM-602’s socket does not have this issue any longer—it was present in the preproduction version.
HM-602 Unpacking Video
HM-602 firmware now displays correct device identifier and implemented the following bug-fixes/changes I could detect:
- Automatic media scan to update SD card files during bootup
- Menu Settings hides EQ, User EQ and Recently Played options by default, so my suggestion is that you start by configuring the Main Menu options to your liking before starting to use the device
- Same SD-card requirements as the HM-801. My recommendation for a preferred and fully compabile SDHC card is documented here: http://www.head-fi.org/forum/thread/450722/hifiman-hm-801-sdhc-card-list/15#post_6886890. Lesson: be aware of fakes!
- Shipping firmware version is 0.03, dated 9/1/2010.
Comparison Test Preparation Notes
All IEMs and full-sized cans were custom cabled using Whiplash Audio TWag or TWag X Reference replacement cables.
Virtually all IEM-testing was done using the JH13 Pro for two reasons:
- Even at low gain settings the JH16 Pro is a bit to sensitive for the HM-602, although you can hear no hiss or channel imbalance, I cannot exceed 2 out of 10 on the volume dial using them without hurting my ears, and it’s not much more for the JH13 Pros either. Your mileage—as is your headphones—may vary.
- I wanted to compare both of DAPs using a more neutral and analytical IEM primarily vocals, new age, jazz studio and progressive rock recordings, generally considered more suitable for the JH13s than the JH16s
HM-801 GanQi amp module configuration: GAME adapter card.
HM-602 Gain setting: Low
Volume Matching: by my ears, best effort
Full-size Headphone Testing
I have chosen two widely known and available headphones to in this comparison:
- Whiplash Recabled Sennheiser HD600 for more analytical and balanced representations compared to the warmer, slightly darker sound signature of the HD650s
- Whiplash Recabled Sennheiser HD800s
As shown in the photos, the balanced phones were used via custom-built 3-pin XLR to S/E 3.5 mm TWag X adapter.
HM-801 GanQi amp module configuration: ST v2.
HM-602 Gain setting: High
Volume matching: via SPL meter via iPhone4 UE Application (75dB peak - 58 dB avg.)
Test Recordings Used
16-bit FLAC recorded to the same Kingston 32GB SDHC Card (HM-602) and HM-801 built-in flash memory. Even though both players are capable of 24/96 playback, as it has been previously confirmed by Fang that the HM-602 can only accomplish this via downsampling to 24/48 due to the limitations of its Phillips DAC chip, I decided not to use this material as this process almost always introduces some unwanted artifacts. Regardless, this is still a key advantage for those who already own an HM-801 and decide to purchase an HM-602 as well, since the same SDHC cards will work just fine in both units regardless of the recording bit- and sampling rates.
- The Alan Parsons Project – The Time Machine (Japanese Master Recording CD)
- Bella Sonus – Enamoured (CD)
- Julianna Raye – Dominoes (Bowers & Wilkins Music Club Download)
- Ottmar Liebert – Up Close (Binaural Recording – CD) --- Thanks to Maxvia for the recommendation!
All TWag and TWag X Replacement cables used during the tests are considered fully burned in (300+ hours each, including the balanced to s/e adapter)
All Headphones and IEM used have at least 250 hours of burn-in time logged
HM-801: both GanQi modular amp modules have at least 200 hours or more burn-in
HM-602: assuming the (advertised) mandatory 24-hour minimum Head-Direct factory Q&A burn-in test period, the tests were conducted only at about a 40-hour watermark, which should be noted as a detrimental or at least a random element here. I will post updates to this review should there be significant improvements worth noting, as I’m sure so will other customers as more preorders get fulfilled and additional impressions are posted.
HM-602 vs. HM-801 Comparison Test (JH13 Pro)
This test was primarily conducted by quick A/B switching with both Bella Sonus and Julianna Raye copied to the HM-801s flash memory to avoid having to switch both the card and the headphone. Volume matching was difficult on the HM-602 but I did my best to achieve parity with the GAME equipped HM-801.
Normal listening/testing volume:
Sonic Evaluation Highlights:
Essentially, the differences between the two HiFiMAN products have grown since my brief evaluation of the preproduction unit. In fact, I would venture that using the TWagged JH13 Pros (a key differentiator vs. the JHA stock cabled one), the sound signature delta has grown. These are the biggest differentiators I was able to detect with my ears in a few hours of listening time:
- Imaging and soundstage: The HM-801 is capable of projecting a much wider soundstage and a more laid back presentation than the HM-602. Tracks like Dominoes and White Bicycle on the Julianna Raye album were proof positive of this.
- Detail and instrument separation: Both units aced this one but the HM-801 still had a slight edge primarily in acoustic transients such as the flamenco guitar work of Ottmar Liebert on the binaural tracks.
- Dynamism and Viscerality: Interestingly, I liked the HM-602 better, despite the narrower soundstage. Snare and kick-drums, as well as drum computers on the Bella Sonus album sounded more natural and elemental than on the HM-801. Not sure if this will change or mellow out during more burn-in, but for now it was a pleasant surprise for me
- Frequency response: I have no equipment to produce a graph, but I could detect minimal treble rolloff with the HM-602 and virtually none with the HM-801. Both units are capable of excellent bass representation, but to my ears, the HM-602 has produced a warmer, less analytical, but perhaps more natural sound, which was very pleasing to me. More forward, yes, but with better mids almost an analog-quality sound.
Fang has mentioned during my pre-testing audition during the Can Fest that the differences between these units became more pronounced thru external amplification and high-quality speakers. I have nothing to contradict this statement, but I do not have a speaker system to validate this, nor was that in scope of my original test plan. Regardless, since the design specs—at least as far as the HM-602 opamp/analog board is concerned—have been fine-tuned, this no longer applies as much it once may have, especially when compared against the GAME card equipped HM-801 vs. the Production HM-602.
The HM-602—based on this preliminary evaluation—presents a compelling argument for those HM-801 owners who were contemplating purchasing an additional GAME card for their shiny new IEMs. Aside from a wider soundstage and some superior resolution and transparency advantage, they may as well considering obtaining an HM-602 for that purpose and take their SDHC music in their pocket on the road with better battery life and acceptable tradeoffs in sound quality.
And the HM-602 isn’t even close to being broken in yet, so the soundstage is expected to widen some more, I’d think. From where I sit, all of Fang and his team’s effort to bring yet another quality product to market may have just succeeded, if the quality of my unit will be representative to the shipping version soon to be made available to those eagerly awaiting them.
HM-602 vs. HM-801 Comparison Test (Sennheiser HD600)
Normal listening/testing volume (for both Sennheisers due to identical, 300 Ohm impedance):
HM-801 (STv2): 5
It never ceases to amaze me, how much switching out the two GanQi amp modules change the sound characteristics of the HM-801. Clearly, this is not an option for the HM-601, but it just demonstrates so well the advantages of the modular concept of the Big Brother HiFiMAN player.
I like the recabled HD600s because they are true reference headphones. It won’t compensate for recording or source inadequacies, it simply tells you like it is. Sure, it needed a $400+ cable to enable it to do so but in return it elevated this, relatively inexpensive Sennheiser into a precision aural scanner transmitting very precise, minute details about the performance of these two players.
The result is sonic excellence with minor differences along the lines of the JH13 results, which is why I’m not going to repeat those findings here. In short, slightly narrower soundstage, warmer, to my ears more appealing sound signature and more visceral presentation of the HM-602, however, the synergy of the HD600 must have been better with the HM-801 because it performed considerably better in this area than the GAME amp/JH13 Pro combo did in the previous test. I did listen to these headphones with both players for hours and never once felt fatigued or lacking in anything in terms of overall sonic presentation.
HM-602 vs. HM-801 Comparison Test (Sennheiser HD800)
I have started this test by playing Julianna Raye’s Drewberry Wine starting with the HM-602 after volume matching had been completed. Despite my earlier sessions with both the JH13s and the HD600s, these TWagged HD800s made me believe that I had been, in fact, listening to my Cary CD303T Pro SACD/Apache combo in balanced mode. This little player can do amazing things, but at the same time, let’s remember these were Sennheiser’s top-of-the-line dynamic headphones sporting similarly excellent cables. Regardless, the HM-602 was effortlessly able to drive these cans. The famous HD800 imaging was all there, perhaps a bit more pronounced with the HM-801 as before, but the difference had narrowed some. But the warmth remained, at the expense of the HM-801. At the same time, I detected more sibilance in the HM-602s presentation, not too pronounced but definitely there, where as the HM-801 remained buttery smooth in its delivery. Perhaps, this is another artifact that will diminish later as part of the burn-in process, but even if that doesn’t happen, considering the overall price/performance factor—barring any quality-control issues associated with supply-chain or manufacturing process in mass production—Head-Direct will have a winner on their hands.
In case you left wondering, I have been duly impressed by this new addition to the HiFiMAN franchise as I suspect most customers will be. Readers should be aware, however, that some of the best available interconnects and headphones were used in this evaluation. This is as it should be, because you need very resolving equipment to detect any source limitations and the HM-602 is certainly good enough of a source to warrant a serious investment in a top-of-the-line universal or preferably custom IEM to shine.
Possible Areas Of Improvements
In terms of a wishlist or suggestions for improvements I can offer precious little, except that I hope Head-Direct will find a way to offer an optional case for this product, preferably with a belt clip or loop that enables it to be carried that way. Unlike its big brother, it is more easily pocketable and offers a much better battery life.
What didn’t—and couldn’t have—improved is the much-requested and missed capability of gapless playback. The firmware has been tweaked to the extent possible within the limitation of the main controller chip present in both HiFiMAN units. Unfortunately, unlike those of many competing products, this hardware does not offer a fully gapless playback support capability. Instead, customers will have to settle what Fang refers to as “near-gapless” playback capability. This is essentially a sub-second audible gap between songs. Not a deal breaker for most but will be for some, no doubt.
HiFiMAN UI: has been stabilized, based on my limited exposure to this version, however, this review was written from an HM-801 user’s perspective. If you are accustomed to the slick iPod UI or that of another, more mature player, you may very well find the HM-xxx UI to be somewhat less fluid and counter-intuitive in some aspects. No album art support and the overall control scheme will involve some getting used to, to say the least. But it is functional and works.
Playlist support: I did have issues trying to use CUE lists, so if someone figures out exactly how to create proper CUEs using software such as XLD on the Mac, be sure to let me know so I can update this review. Until then I’ll consider this issue unresolved.
Regarding the firmware, during 3 full days of regression, comparison and burn-in testing, I had no issues whatsoever. Not one freeze so far and I sure hope my luck will hold, but this definitely reinforces my feeling that the spirit of incremental improvement is much more than just a lip service at Head-Direct. No single product is perfect and there are plenty of alternatives to choose from in this crowded MP3-player market.
But those who wanting something different than an iPod or iMod/WhipMOD because you hate iTunes—remember that Steve Jobs just doubled the bounty for each and ever one of you and knows where you sleep—and considered the HM-801 either too expensive, unwieldy or your Diesel-powered generator couldn’t handle the additional load in exchange for that aural bliss it provided…you may consider those objections OBE courtesy of the HM-602.
Finally, I will post updates in the next few weeks as new information becomes available and what improvements (if any) further burn-in has yielded.
Update 1: Observed battery life under real-life usage patterns using SDHC media described above with JH13 Pro: approximately 8 hrs from fully charged to automatic shutoff.
File formats supported (same as HM-801):
FLAC -- lossless VBR-44.1kHz and 24bit-96KHz (downsampled to 24/48)
APE -- Fast, Normal, and High Mode
AAC -- 16K-320Kbps
WMA -- 8-355kbps
OGG -- Quality 0-Quality 10
WAV -- PCM,MS-ADPCM,IMA-ADPCM
MP3(VBR) -- 8-320Kbps
Update 3: Proper USB Data Exchange connection procedure for the HM-602s internal flash drive:
Turn off HM-602
Connect supplied USB data exchange cable
HM-602 turns on automatically into USB data exchange mode
When I tried to connect the HM-602 while it's on I have observed the drive mapping disappear several times after a about 10 seconds for reasons unknown. Following this procedure allows it to stay active indefinitely. Also, the formatted size of the flash partition is actually 16.5 GB (FAT32).
Edited by warp08 - 9/29/10 at 4:58am