Ultra High-end, Best Sounding Portable Music Player Available Today
Portable digital music players have much to offer in terms of mobility and convenience. But the sound quality is definitely lacking if you want to experience the full sonic potential of 24-bit music files. Up to now to enjoy the highest resolution lossless music, you would need to use your computer or a desktop component. So HiFiMAN's Fang Bian developed the HM-901, a truly audiophile portable music player that's packed with innovative performance enhancing technology.
In addition to offering unrivaled sound quality, the new HiFiMAN player accepts a wide array of audio formats, is expandable, and is easy to operate, thanks to its advanced used interface. Three years in the making, this remarkable HiFiMAN reference player is destined to set a new standard for true audiophile-quality portable devices. And the HM-901 can function as a network music server.
Dual 32-bit Sabre DAC Chips
The HM-901 uses two Sabre ES9018 32-bit DAC chips, currently the most expensive and top-of-the-line DAC chip available. It will play 24-bit 192 kHz high definition music files and offers upsampling to 24/192. It accepts most lossless audio formats. Supported 16-bit file formats include mp3, flac, ape, aac, alac, aiff, and wav. Supported 24-bit file formats include mp3, wav, flac, and alac.
Sound quality is beyond amazing. According to HiFiMAN Founder and President, Dr. Fang Bian, "The HM-901 has been extensively tested in double-blind listening sessions and compares favorably to the highest quality reference digital playback systems."
High-end Step Attenuator Volume Control
Also contributing to the HM-901's sonic excellence is its very high-end step attenuator volume control, which is a product that you will not find in another manufacturer's portable audio device. It's an expensive item to include in a mobile player. But the benefits are worth it. "The advantage is that the resistors in both channels of the step attenuator can be paired to make sure they are 100 percent identical," says Fang. "So the soundstage will be much more accurate than with regular volume controls."
And speaking of the volume control, here's a nice feature. The patented volume control is recessed in the front of the case so that you are highly unlikely to ever change the amplitude by accident. "Even if the front rubs up against clothes or other surface, the volume will not change," says Fang. "This is necessary to help protect your ears, because the amplifier module for headphones is very powerful."
Powerful Amplifier Module
The HM-901 boasts a uniquely designed headphone amplifier module. It uses four OP627 chips, which is one of the most expensive op-amps available, and OPA634 buffers, which also is a very high-grade chip from Texas Instruments. As a result, the sound quality is very impressive.
The headphone amplifier is located on an easily removed module. This makes the HM-901 great for tweakers who might like to experiment with different amp modules. HiFiMAN is currently developing an extra powerful 6-volt-output amplifier module card which can drive most full-size headphones
In-ear headphones demand very high signal-to-noise ratio, but don't require high output, because the efficiency is high. Full size headphones typically have very low efficiency and the impedance is relatively very high.
To excel with both types of headphones, the MH-901 has a low-gain output and a high-gain output switch. Low gain is for the smaller type headphones, like earphones, earbuds, in-ears. The high gain is more powerful and is designed for use with full-size headphones.
Balanced/Normal Mode Selection
Also unique to this player is a patented system allowing you to select either Balance or Normal mode playback via a convenient switch on side. Balanced is for four-pin headphone plugs (separate 'plus' and 'minus' for each channel). Normal is for the standard three-pin mini-jack output, with both channels using a shared ground.
"The balanced mode has much more powerful output then the normal, because the balanced amplifier is four times more powerful," notes Fang. "The channel separation is much higher, so the soundstage is much larger. The balanced mode is perfect for all of the HiFiMAN high-grade headphones, which all use the four-pin balanced connections."
Another great feature of the HM-901 is the HD and Vintage switch, which alters the DAC frequency response. HD means high definition, and there is less roll-off in the high frequencies. It's a more modern sonic signature. Vintage gives you 3 db roll-off at 20 kHz to mimic the softer sonic signature you get from classic hi-fi gear.
Easily Replaceable Rechargeable Battery
Unlike other portable music players, the HM-901 is not a 'disposable' audio product. It is built to deliver exceptional performance for years and years. Reflecting this philosophy is its replaceable rechargeable battery. It's easy to open the back and swap out the battery when you need to. And it's a very large and robust battery unlike the power source you'll find in other portables. It delivers +/- 7.4 volts, 2,000mA.
Interchangeable SD Card Memory
The HM-901 uses an SD card for maximum convenience. So instead of relying on an internal flash memory which would be difficult or impossible to replace, just pop in your own SD card. "With an SD card, you can buy several and switch them out and easily have several hundred gigabytes worth of digital files."
Even More Features
In addition to all of these great features, the HM-901 also has a custom-designed TAICHI user interface for exceptional ease of use and fast response. It offers digital input/output and USB decoding through an optional docking station. The sleek, robust case is constructed from high-tech composites.
Forthcoming firmware upgrades will allow the HM-901 to function as a Wi-Fi music server and will also allow gapless playback of digital music files.
We asked HiFiMAN founder Dr. Fang Bian to give us some background insights into the HM-901 portable digital player. He was kind enough to answer our questions about this amazing product.
Q) What was your main motivation in designing the HM-901 music player?
A) Early on, I was a well-known expert in Asia for Walkman/Discman players and earphones. So it was only natural for my dream to create the ultimate portable player. There was no such thing as a high quality player in the market before 2008 when we introduced HM-801. In 2008, we made HM-801, which become a world famous product, It helped launch HiFiMAN and also started the true portable hi-fi player market. However, the HM-801 was only the beginning and there was so much more potential in the concept. And that led us to the HM0901.
Q) Can you talk about the comparison between the evolution of camera gear and hi-fi equipment over the years?
A) If you examine the camera market, you will see an interesting parallel to audio players. First both involve digital imaging. At the entry level, you have cell phone cameras that take photos and play mp3 files. Both are adequate but not all that good. Move up in digital cameras and you can get better images and resolution, and the same would be true in iPods and portable music players. If someone desires the highest quality digital images in photos, you have to get a digital SLR. The same is true for the serious music lover who wants the highest resolution and best-sounding music. Think of the HM-901 as equivalent to a professional grade digital SLR.
Q) What is unique about the user interface of the MH-901?
A) The user interface was called Taichi UI because of the circle design concept on both the physical wheel and the virtual circle in the screen. Physical wheel vs virtual wheel is the design idea. The physical wheel concept, which is easier to use, even compared to the iPod wheel, is widely used in professional cameras. The feedback we have had in our user tests has been very positive.
Q) Who do you see as the customer for the HM-901?
A) Traditional hi-fi customers. High level headfiers/musicians who desire the best sound on-the-go.
Q) What are your plans for accessories to go with the HM-901?
A) Different amplifier modules: Standard card for portable headphones and IEM, balanced card for most full-size headphones and high-end portable headphones with balanced connectors, mini-box card for most portable headphones, some full-size headphones with regular mini connectors.
Also, dock cables: Dock to 3.5mm line out, dock to coax in/out, dock to coax in and RCA line out.
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|HM-901 Simply Amazing in every way!|
Two weeks ago I received my HM 901 from Audioadvisor. It came with the standard Opamp. I ordered the balanced amp from Headirect about a week ago. Since then I have been doing a comparison between the standard stock amp and the balanced amp. I have also been switching back and forth between the hi Ėres and the classic switch. The headphones I have used are the Shure 1840, Grado 500, Sennheiser HD600 and my Sennheiser HD650. I owned and sold my HM801 so I no the difference in performance between both of them. I also owned the HM601 but will not use this to compare either since it is not in the same league. Simply put the HM901 is better then the HM801. I thought the HM801 would be hard to beat. I also thought the HM901 with the saber dacs would sound drier and not as analog as the HM801. It doesnít. My 4pin balanced 3.5 mini cable is from Charleston Cable company. Manufactured here in the good old USA. I purchased two of these. They are beautifully made, and the sound quality is exceptional. I can honestly say this having used various major brand cables on my HD600 and HD650. That said I highly recommend the Charleston/Audience cable. He is a great guy to deal with and very customer service oriented. Not to mention the quality of this cable. The cable he uses is designed and manufactured by Audience. This is simply my opinion. I have nothing to do with this company. Do a search for additional information. My experience in music professionally has been a long one. I have been fortunate enough to have owned and tried many hi-end stereo products. I wonít go in to a long detailed description in terms of the sound quality the HM901 produces. There will be plenty of professional reviews coming out soon. Having said that I will say Fang did one hell of a job designing this. Is the body brushed aluminum. No it isnít. Itís plastic. Does it feel like a $1000.00 portable player. In a way yes it does. Does it look good to the eye. Well beauty is in the eye of the beholder. To me it looks fine. The plastic is a high grade plastic. The seams are perfect. Everything looks like they took their time to assemble it. Pride maybe. Whatever it is it just works. It feels right in the hand. It is easy and friendly to use. To me I really like the way it looks. How does music sound on this amazing digital player. To my trained ears it sounds perfect. My stereo home system is top of the line. I now spend 90% of my music listening with the HM901 and my Sennheiser HD650. I do prefer the 24 bit music though. Just a bit more quality, detail, etc then 16 bit. Not a lot but enough. To me itís definitely noticeable. I am a person who is very very picky about the sound quality of the music I listen to. Sometimes maybe to picky. Especially how itís produced through the equipment playing it. I do highly recommend the balanced amp over the mini amp and definitely over the standard amp. There is a quite a noticable difference between the standard and the balanced amp. I havnít had any trouble with any particular manufacturesmemory cards although I prefer sandisk. The latest firmware works fine. Didnít change the sound signature or cause any problems. Easy to install. Twice it skipped ahead on one of the songs I was listening to. That was before the firmware. Never did it again afterwards. Iíll see what happens down the road. I Love everything about the HM901. To me it was worth every penny. To here music produced with this high quality coming from such a small device is amazing. I am listening to sound quality that I enjoy as much if not more then my home system. And all this coming from a portable player. I couldnít ask for more. Fang did a super job in the design, build and quality of the HM901.
|- DAVID MICHAEL, MD|