General Information

The HA-2 is an elegant yet sophisticated portable headphone amplifier with built-in rechargeable battery. It is engineered to enhance music playback from mobile phones and portable music players. Aesthetically, the HA-2 does not look like a typical or generic electronic device. Its genuine leather casing with contrast stitching and beveled aluminum edges are eye-catching and cannot be confused with any other product. Its fit and finish will instill a sense of pride when using the product.

Featuring hybrid class AB amplification and a USB DAC that supports 384 kHz PCM and DSD256, the HA-2 offers high performance digital-to-analog conversion for Apple’s iPhone/iPod products, a wide range of Android devices, PC and Mac computers. The HA-2 may be conveniently used to charge mobile devices on-the-go and itself can be efficiently charged in 30 minutes. Headphones, from very sensitive In-Ear Monitors to the most power-hungry Over-the-Ears, can all benefit from the HA-2’s excellent performance and powerful amplification.

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Reviewer for The Headphone List
ryanjsoo's Reviews
Pros: Neutral, resolving, detailed sound, Luxurious build, Nice dimensions for stacking, Power bank functionality, VOOC Fast Charging
Cons: No USB charge switch, Batterylife shorter than competitors
Introduction –

Like Xiaomi, Oppo leverage their smartphone mass manufacturing prowess to produce interesting takes on conventional technologies. The AMP/DAC market is an interesting field in that it is simply so diverse. As with many users, my first DAC was the Fiio Q1, a solidly built, well performing device and I was content with it in all aspects. But that was until I heard the Chord Mojo, a completely proprietary device that illuminated acoustic intricacies like no other. But whilst Fiio and Chord provide two very impressive devices at opposing extremities of budget, Oppo bring a new contender with their larger economy of scale and design expertise.


Meet the HA-2, a luxury DAC/AMP that promises seamless smartphone integration with all the convenience of a consumer product but the sonic finesse of an audiophile system. With an RRP of $450 AUD, the HA-2 lies right in the middle between the Fiio E17K and Chord Mojo; but does its performance live up to Oppo’s reputation (earned by their renowned PM headphones) and can the HA-2 compete in a market so honed from years of audio experience, let’s find out.


About Me – Some background, Gear of choice, Preferences and Biases

I generally prefer a slight v-shape to my sound, but still closer to neutral. I like a lot of detail and clarity, but can appreciate a smooth, laid back sound such as that on the X10`s. I prefer a more neutral midrange within a relatively tight tolerance, but I`m probably more forgiving of brightness over darkness. I`m not particularly treble sensitive and can tolerate large amounts without fatigue, though too much ruins the enjoyment. If I use a different eartip/pad/cover during the review I will note that and describe the sound changes.

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Accessories –

Starting with the packaging, Oppo certainly doesn’t disappoint with a very professional design whose darker theme contrasts to the brighter palette assumed by Fiio.

Bold renders adorn the front and right side whilst concise infographics line the left; Oppo also provide a comprehensive list of specifications on the rear.


As one would expect from a manufacturer such as Oppo, it’s similar to unboxing a premium smartphone, which is to say, a very visually impactful experience on a whole.


Like the PM3, the HA-2 lies safely packaged within a hard shell within the display box. Lifting off the top panel users will find the accessories:

  1. Manual
  2. Warranty papers
  3. 5mm Interconnect
  4. OTG cable (Android)
  5. USB A to Lightning cable (IOS)
  6. Two stacking bands
  7. Micro B charging cable
  8. 5A Oppo VOOC AC Fast Charger


It only takes a glance to notice that the HA-2 ships with a very comprehensive list of extras, the most notable perhaps being the charger which is all too often omitted. The quality of these accessories is what you would expect for $450, the cables are well molded and pliable and the stacking bands are even pre-formed to the dimensions of the HA-2 (and thus pretty much any ~5” smartphone). Attention to detail is key here and Oppo certainly delivers.


Design –

The HA-2 makes quite the first impression; the impeccably assembled, leather clad aluminum chassis has the nuance and ergonomics of any flagship smartphone. The subtle chamfers that adorn each edge and the slight countersinking of each port convey the level of thought that went into designing the HA-2.


Whilst some question the leather wrapping (glued on, stitches are for aesthetic purposes only), it does prevent scratching both the HA-2 and your smart device. The leather also provides a really nice feel in the hand, the supple feedback and texture contrasting to the cool metal. As I learnt the hard way, the leather provides just a hint of shock absorption should you drop the heavier device.


Moving onto the aluminum body, the HA-2 is roughly similar in size to the Fiio e18 but is a little slimmer. It`s substantially larger than the E17K and Q1 however (comparison photos below). The interfaces follow an intuitive pattern with the inputs and input switch on the bottom and the headphone and line out ports located on top. The HA-2 communicates through a USB-A or micro-b port when using both the inbuilt DAC and AMP, but accepts a line-in signal through the line-out port when functioning purely as an AMP.


The micro-b port also doubles as the charging port and supports Oppo’s proprietary VOOC fast charging technology. Combined with the potent 5A wall adapter, the HA-2 managed to top off in just over an hour. From full, used as both a DAC and AMP, Oppo claims around 7 hours of batterylife. I managed to scrape 7 hours and 20 minutes in my uses which is good but not great; the E17K offered twice the batterylife whilst the more expensive Chord Mojo produced about the same performance. One feature I did appreciate on the Fiio DACs was the option to toggle USB charging. Since the HA-2 has no such option, it simply charges off any source. This is fine when playing off a laptop or PC but when used with my aging HTC M8, the battery drains quite quickly with no option to use the internal cell of the HA-2 (the HA-2 only charges devices through the USB-A port not the micro-b port). Unlike Fiio DACs, when used with a PC, Oppo also requires the user to download a driver prior to use, but once the driver is installed, the HA-2 is plug and play.


The USB-A port is perhaps the most convenient aspect of the device. The HA-2 has a camera connection kit built-in, allowing it to accept a digital input from all apple devices using only a conventional USB cable, omitting the use of an adapter. It also allows the HA-2 to function as an external power bank, charging devices from its in-built 3000mah battery (@500mah). The source switch allows users to toggle between the three inputs, A, B and C corresponding to USB-A, Micro B and Line-in ports respectively.


The HA-2 has a smooth analogue volume pot with a very grippy texture. Despite this, the pot is still relatively difficult to rotate, reducing accidental volume changes during transit. The pot doubles as the power switch, much like the Fiio Q1 with super clicky feedback. Both channels are also well balanced above 1 of 5 volume notches which will be the useable range for the vast majority of users.


The right side of the HA-2 houses the 4 LEDs that denote remaining charge, a button to activate said LEDs in addition to two switches that toggle low/high gain and bass boost. I appreciate how the battery meter functions even when the device is off. Holding the button enables power bank functionality and an additional blue LED illuminates to denote that the HA-2 is charging your device. I do enjoy the congruency between Oppo’s colour choices with matching pastel green denoting power and charge, it contrasts quite nicely to the black and silver.


So that pretty much sums up the HA-2, it’s a very nicely designed product that is perfectly actualized by strong manufacturing processes. Whereas even the nicely built Fiio e17k has a few defects and limitations with its build, such as slight flex to the chassis and the plastic volume wheel, the HA-2 leverages Oppo’s manufacturing power to create a very discrete device.


Sound –

Utilizing the renowned Saber ES 9018-K2M DAC chip along with an AB amplifier, the HA-2 produces a very clean, detailed sound combined with plentiful output current for a portable amp. The HA-2 also supports a huge array of files and sampling frequencies though I won’t detail them all here. You can see the specifications and supported file types below:


One aspect of sound that tends to change significantly as you head into higher end gear is the soundstage. While the Fiio E17K already had a pretty good soundstage, overall, the HA-2 sounds much more spacious, especially when the track calls for it. Plugged up to my Sennheiser ie800`s, the HA-2 feeds them with hyper accurate imaging and a very broad sense of space. The Saber DAC produces superb instrument separation with fantastic timbre and resolution. The large soundstage of the HA-2 is perhaps one of the main reasons it pairs so well to the Oppo PM3, a generally more intimate sounding headphone.

As for the AMP section, the HA-2 produces a very slight background hiss with my UM 50 Pro’s and Shozy Cygnus but not my ie800’s or Oppo PM3`s. There’s a similar amount of noise as the E17K but it’s a lower frequency hiss that`s less distracting. Both aren’t really noticeable when music is playing and I have to concentrate to hear it. With sensitive monitors, there is a noticeable increase in noise when switching to high gain but users shouldn`t find any issues with high gain for more insensitive headphones. For all effective purposes, the HA-2 is essentially silent. The HA-2 has no troubles driving any of my gear, though admittedly I don`t have anything particularly difficult to drive. The HA-2 does offer plenty of current for lower impedance gear and I can`t approach top volume even on low gain, I use about 1 and a half to 2 of the 5 volume steps.


Comparisons – 


At 3x the price, the HA-2 offers large performance gains over the Fiio E17K but the differences are still a lot more nuanced than those you would get by upgrading your earphone/headphone. Starting with the tonality, the HA-2 carries the typical crisp and clear Saber sound whilst the E17K carries Fiio’s warmer house sound. As a result, the E17k produces a slightly fuller low end and a darker midrange. Despite this, sub-bass seems more extended on the HA-2 and bass notes in general are tighter with more resolution. The HA-2 also reveals a more refined mid and high end response. Treble notes in particular sound smoother and less crunchy than the E17K whilst resolving a higher amount of detail. The E17K on behalf of its darker midrange does have a more “isolated” treble response which can appear more defined on first listen, but prolonged comparison reveals that the HA-2 has the superior response in culmination with a more balanced sound on a whole. Overall, the HA-2 just sounds cleaner and more composed than the E17K. It also helps that the HA-2 has a lower output impedance at 0.5ohms vs 1.1ohms on the E17K making the HA-2 better suited for sensitive multi-armature or hybrid earphones.


What the HA-2 lacks is the flexible eQ system of the E17K which allows it to vastly alter its sound signature. The HA-2 does have a bass boost, which I found to be particularly tasteful giving just a slight bump to the very lowest end, mainly the sub-bass. The bass boost functioned almost identically on my Alessandro MS1’s as the tape mod, creating a much more balanced sound from the more anemic Alessandro’s with bowl pads.

But how does the HA-2 stack up against something a little closer in price such as the Chord Mojo? When I first tested the Mojo, what stood out to me most was the sense of effortless detail and black background. The E17K has great detail and dynamics but lacks this element of refinement. So perhaps the biggest advantage of the HA-2 over the e17K is that it reproduces sound almost as effortlessly as the Mojo for just half the price. Whilst the Mojo is the perfect mix between the lush E17K and the clean HA-2, the Oppo is much closer in performance to the Mojo than it is to the E17K despite being between the two in price. The E17K tends to get a bit overwhelmed when the track gets overly complicated, the Oppo retains composure much like the Mojo.


Verdict –


The HA-2 is ultimately a very competitive device. Whilst users perhaps won`t find a particularly substantial upgrade over lower priced DACs from Fiio, the HA-2 nevertheless produces very impressive results, especially at its price. As far as usability goes, the HA-2 excels over almost every competing model with a housing specifically designed for stacking and other more unique features such as the in-built camera connection kit for IOS devices and power bank functionality.

Whilst the HA-2 doesn’t offer groundbreaking proprietary features like the Mojo or a flexible eQ system like the E17K, a thoughtful combination of premium components and meticulous attention to detail create a device with few compromises. The build and functionality are surprisingly well rounded and the HA-2 feels immensely focused. Although the HA-2 is not a cheap device, Oppo make the customer feel as if they`ve gotten their money’s worth.

Accessories – 10/10, Comes with all the cables you could want apart from a 30-pin connector for older Apple devices. Nice stacking bands. Comes with a 5A fast charger and a very low guage charging cable which is a rarity even among $400 smartphones.

Design – 10/10, A great design actualised through perfect manufacturing. Rock solid chassis accented by green LEDs and subtle chamfers. Analogue pot produces no noise and is well weighted. Buttons are super clicky but bass boost and gain switches can be hard to differentiate in the pocket. Powerbank function works well. No option to turn off USB charging is disappointing but can be remedied with the right cable.

Sound Quality – 9.5/10, Largely improved SQ over Fiio DAC’s with a lower output impedance and a more neutral sound signature. Fantastic resolution and sound staging. Top tier detail retrieval whilst remaining composed with impressive refinement. Slight background hiss, brighter earphones can sound slightly overbearing coming from a darker source.

Value – 7.5/10, Still doesn`t meet the outright value of Fiio DAC’s but improved build and sound do somewhat justify the price increase. At the end of the day, the HA-2 is a luxury item but performs like one too.

Overall – 10/10, The low noise level, low output impedance and smooth, well balanced volume control work wonders for sensitive iems whilst offering enough current and voltage in high gain to satisfy larger headphones. Other notable features include the supple authentic leather wrap, superbly machined aluminium body, ultra clean sound and spacious soundstage. The inclusion of VOOC fast charging makes the HA-2 a multi-purpose device, doubling as a decent powerbank. The HA-2 impresses in all aspects.

Thanks for reading! This review was taken from my blog, please have a look for more reviews like this, guides and more:


Great review. I don't notice any hiss with even my sensitive IEMs. I use this paired with my Fiio X3ii. It can easily drive my AKG 7xx. I went to the Oppo HQ in Menlo Park, CA and tested all their gear and of course got this before leaving
I love the HA-2 pairing with both my JH 13v2's and Roxanne's! I especially like the HA-2/Roxanne pairing as the Roxanne is known as a typically darker (warm, full sound) IEM and the Sabre chip does an especially good job bringing out the brighter side of the spectrum, which results in a really nice, balanced, full sound with a great soundstage.
Fully agree with the review. I own one and I'd describe it very similarly.


Pros: Sound quality is near-desktop level when paired with Oppo PM-3
Cons: No phone capabilities. Jury out as to whether it will pair with other 'phones as well.
I set out to do a very unfair comparison:  my new Oppo HA-2 from iPhone vs my Desktop of the Schiit Asgard 2 from Optical Modi from iMac 2011.  Both systems driving my fairly new Oppo PM-3, which I love, but didn’t find well-served by my SoundBlaster e5 unless I tinkered quite a bit with its DSP and equalizer.  I found the claimed Oppo goals, and various Head-Fiers enthusiasm, to be well-justified in the Oppo pairing.  Indeed better sound quality than the PM-3 to e5.  So good, I wondered:  how close is this quality in a portable rig to my desktop configuration?
While trying to find this out, I learned some things about my gear, both desktop and portable, that made the trouble I took worthwhile.  But the short and sweet news is that this portable rig happily comes extremely close to my desktop rig.  I’m not going to think twice about the quality I can get in any chair in the house or any walk-about with the portable Oppo rig.  While occasionally there’s a distinction that justifies the existence of the desktop, there’s plenty of emotional satisfaction from the quality of the portable rig.
But only if I get all the settings right. 
In the first three comparisons below, the Oppo portable rig actually outperformed my Desktop rig.  That didn’t seem right.  Now, when I take the test of 6 tracks in the NPR test of “Can you hear a difference between file formats?” I only score 3 or 4 of 6.  I usually avoid the 128 kbps  file, but have trouble between WAV and 320 kbps.  I don’t consider my hearing “file sensitive” past the current Apple streaming at 256 kbps, and my plan is to shift my budget of music acquisition to streaming Apple Music.
But...it turns out that some of my favorite tracks, being favorites, were ripped early and consequently at 192 kbps mp3.  So the first accidentally happy news is that my gear now allows me to distinguish qualities that I had, to date, overlooked or could not detect at all.  My gear has caught up with my ears!
OK, after some re-encoding (much more to go!) the comparisons are now truly unfair, but “real world.”  Portable rig at 256 kbps AAC streaming (via home network) vs Desktop rig at Apple Lossless quality. One more caveat:  because the Oppo HA-2 “releases” the iPhone after a certain time, volume level-matching by ear has to occur at almost every comparison.  This really dilutes the scientific method, folks.  When I’ve felt I was hearing something different, I often tried again at slightly different volume to see if the distinction persisted.
So, here’s the question of the day:  If, for “serious listening," I take my portable to the living “comfy chair” instead of at the home office Desktop, what kind of quality am I giving up, if any?  Time to compare tracks.
Telarc’s all-digital recording of "In The Mood," Glenn Miller Orchestra
     Desktop: Excellent bite to the brass.  The bass is a bit undefined, as I’ve always heard it on my speakers.  Sax trade-off section is produced to be very L-R, but later the centered trumpet adds a sense of soundstage rather than old-timey “stereo” (a la early Beatles).  The trumpet solo shifts from pealing to growling are well-displayed.
     iPhone:  A bit more spaciousness; the bass definition is more clean but perhaps not as deep;  No difference in L-R placement of saxes.   The cymbals perhaps a bit less crisp.
Pat Metheny & Lyle Mays, “Ozark”.
     - iPhone:  Lyle Mays’ piano urgency in the upper treble is authoritative and compelling, as if your father had just urged you to do a better job, live up to your potential.  The incessant clicking of percussion marks time raggedly, breathlessly.
     - Desktop:  Conveys more of the beauty of Mays’ playing, as though the edge of the treble notes were not quite as harsh.  None of the urgency is lost.  
Manhattan Transfer “To You"
     iPhone:  Wonderful melding of voices who nonetheless maintain individual characters.  Beautiful climb in the piano, etched.  Wonderful lingering to the voices.  Bass swoop not overly defined. Alan’s solo handsomely modulated.
     Desktop: The comparison is so close I had to go back to play one particular passage near the opening.  Perhaps the desktop renders the soprano’s peak of “very” in the line “my very heart and soul,” with a bit more verve, but hearing this is so dependent on a match in overall volume level that I can’t be sure.  
Timothy Nolan, “Sorry-Grateful” on Sondheim 2-disc (out of print0  
     - iPhone:  Captures every modulation of the male voice, presents it all beautifully.
     - Desktop:  Difference too subtle to rule out volume imbalance.
Ahmad Jamal, “Poinciana” on Digital Works. 
     - Desktop:  In the heyday of the CD, I’d bring Digital Works as one of my “test albums” when hunting for an upgrade to my speakers.  Every shop’s manager would ask me to show them the album for their own acquisition.  Surely the playing excellent, the recording superbly intimate in detail yet with enough sonic “room” around each of the trio instruments to make you feel in the room. Tellingly the bass dives deep just as the cymbals ting delicately while Jamal’s piano zooms from subtle to sparkling to thundering.  Few better tests of your system and my desktop system does it justice.
     - iPhone:  Surprisingly and happily close to the desktop:  captures the interplay of cymbal, bass at subterranean levels and crystal-clear close-miked piano.  Exciting on any system, but the Oppo combo stopped me from all else to listen carefully once again. 
The Who, “Slip Kid"
     - iPhone:  After the big bass drum thunders, the count is down, the Townsend guitar must slash, my friends, just slash.  “I’ve got my KIT bag, my HEAVY boots, gonna run ‘till my feet are raw” from Daltrey must have the proper grit and inflection.  This is my anger song and it has to be right.  Hmm, on the portable rig not quite right, on the first try. 
HERE’s the 2nd LESSON:  I changed the setting on the HA-2 to “high” and re-matched the volume levels.  Much better, IMO and to my surprise.  Seems the “low” setting affects more than simply volume.  (The HA-2 volume knob is analog-driven when the phone is set to max volume, as mine was.)  The relationship of treble clarity to midrange changes also, and on High it is closer to my desktop reference - wonderful clarity to the slash without sacrificing the bass drum thump.  Now I truly had difficulty distinguishing the systems. 
So I went back to listen to “Ozark” once again, and can report that Mays’ piano trilled closer to its truth as I know it from desktop and speaker system.
     - As my gear has improved, I’m better able to appreciate the distinctions between higher vs lower kbps files.  Perhaps you’d benefit from re-visting your older file rips, too.
     - The “high” setting on an amp can be a bit more of a pain in that its harder to make fine volume adjustments, but for the HA-2 (at least), the better sound may be at the High setting.
     - With the right settings and file types, the Oppo HA-2 & Oppo PM-3 combo can deliver a sound quality experience so close to Desktop (at my level), that I will find listening anywhere fully satisfying.  If you’re young, you may take that for granted.  I’ve lived through 8-tracks, mid-fi vinyl rigs, and cassette decks that were increasingly better but not near ‘nuff.  I can tell you:  this is a wonderful time to be a walk-about audiophile.  Enjoy!
ADDENDUM - Other HA-2 considerations
Before you rush out to acquire the Oppo HA-2 based on my effusing here, check out other reviews.  The HA-2 isn’t that helpful when you get a phone call on your iPhone.  As far as I can tell, it needs to be unplugged from the lightning jack so you can take the call “normally”.  The Sound Blaster e5 has it beat in that regard.
Also, the HA-2 is a wonderful pairing with the Oppo PM-3 (as we’d hope) but I’m not yet sure it is the go-to amp for other headphones.  My first quick listens on my Grado RS-1 and Momentum On-ear on the HA-2 were not pairings that immediately seemed “right”.  If I learn more about that later I’ll post it on the HA-2 thread.
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Reactions: trellus
THANKS for your research on this pairing of the PM3 and the HA2. informative about the gain setting making a big difference!
Revised my opinion regarding  Senn Momentum On-ear pairing.  HA-2 provides a bit more robustness to the sound.  However, not the "from heaven" pairing that it is with the Oppo PM-3 (on either Hi or Low settings).


New Head-Fier
Pros: Long battery life! Always cleans up the sound! Nothing is over powered! Just awesome!
Cons: N/A
One of the best amps i have owned! It is great and must have for portable audiophiles~! I love it. It has 2 gain levels high and low. Very nice natural sound! If you feel your headphones do not supply enough bass, the Oppo ha-2 can fix that with its bass boost! The bass boost is nice when listening to some really heavy music. The Oppo Ha-2 has to be the best bass boost i have heard. It maintains the natural sound with no variation of distoretion. Really blew me off my feet when i tried it. This is a steal. The big brother desk amp uses the same chip as the oppo ha-2. So to get it for 900$ off is just amazing! I love it and i can not recommend this enough. I looked for portable amps for months and this stole my heart! I use this with my HD 650's. It has a volume nob on it which will not turn in your pocket i have tried everything and it just does not turn unless you do it yourself. It charges fast and lasts for hours like 8 to 10 hours of constant music! It supports apple, andriod, and of course the jack option. Everything was just very well done! I love the way it looks and feels and this is a steal for $300!
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Reactions: RockStar2005
Great review!!
Unfortunately the battery wears over time and especially on cold days it works much shorter time than 8-10 hours, but indeed, its quality is really, really good (except maybe the L/H gain switch which is loose).


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