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OPPO HA-2 review: a must-have headphone AMP/DAC for the mobile audiophile

By Anton D. Nagy December 19, 2015, 10:14 am

If you’re a casual music consumer you’re probably fine with the headphones that came with your smartphone (if any), or you have a pair of earbuds/phones/cans that you prefer to use while on the go, regardless of the smartphone of your choice. If you’re a music enthusiast (or audiophile), however, and you are a perfectionist when it comes to your favorite tunes, you’re either enjoying your content from a computer, HiFi system, or dedicated headphone amp/DAC.

What you do know, by now, is that your smartphone isn’t good enough to drive your (high-end) cans. But, if you still want to enjoy high-quality/high-fidelity music while on the go, with your high-end headphones, this portable headphone amplifier is a must-have, and it’s definitely worthy of an entry on your holiday shopping list.


We’ve tested the OPPO HA-2 over the course of several weeks. We’ve mixed things up a little bit so we can draw the most adequate (see below).


1. smartphones: iPhone 6s, Sony Xperia Z5 Premium, Samsung Galaxy Note 5, HTC One M9
2. computers: Apple iMac, Apple MacBook Air, Microsoft Surface Pro 3, Microsoft Surface Pro 4
3. files: local (256-320kbps MP3 /AAC, lossless FLAC (including HR)), stream (Spotify Extreme quality)
4. headphones: OPPO PM-1, Sony MDR-1ADAC, Sennheiser HD595, Sennheiser HD800
5. inputs: digital
6. genres: rock, pop, dance, hip-hop, R&B, country



In addition to being a portable headphone amplifier and DAC, the OPPO HA-2 is also a power bank, with a 3,000mAh rating, that can charge any smartphone via USB. It supports OPPO’s own VOOC fast charging for topping itself up, and can go from zero to a full charge in less than 90 minutes. The battery, in addition to charging devices via USB, is good for up to 13 hours for analog source listening and around seven hours for digital sources via USB.


At the heart of the OPPO HA-2 is the ESS Sabre32 Reference ES9018-K2 DAC. Measuring only 68 x 137 x 12 mm and 175 grams, it has a small footprint that makes it both portable and pocketable. Frequency response is rated 20 Hz – 200 kHz and is able to power headphones with impedances between 16 Ohm and 300 Ohm. For even more details, make sure to check out the manufacturer’s product page.

There’s no shortage of ports on the OPPO HA-2, offering flexibility to accommodate most, if not all of your needs. In addition to digital input sources (USB for iPod/iPhone/iPad; microUSB for smartphones, tablets, and computers with USB OTG capabilities), it also features an analogue input 3.5 mm stereo audio-in option (that doubles as line-out when digital sources are selected). Switching between inputs is easy with the help of the three-way switch located on the bottom. The USB port is capable of charging devices while the microUSB port is where you charge the HA-2.


There’s a gain switch toggle on the side which allows you to set low or high values, next to a “Bass+” toggle that does what the label implies: boosts the lows a little bit to accommodate those who prefer a bass-ier listening experience.

In addition to the Audio-In port at the top, next to the Headphone-Out port, there’s a volume knob that also acts as a power on/off switch, with a nice click at its lowest setting.

Build Quality


We’ve learned to expect exceptional build quality and presentation from OPPO, and the HA-2 makes no exception. It’s aluminum chassis with chamfered edges is wrapped in genuine leather with nice stitching on the side. Everything speaks premium, from the rewarding click of buttons, switches and knobs to the light emitted by the LEDs (one for power on, next to the knob on the top; four on the side, showing current charge or charging indicator; one on top of the aforementioned, indicating whether the HA-2 is charging a device via USB).


About the only thing we can complain about, if we want to complain about something, is the lack of a carrying pouch or case inside the box. But you do have a set of cables to quickly get you started: a microUSB to microUSB OTG cable, an Apple Lighting to USB cable, and a 3.5mm to 3.5mm analogue audio cable. A VOOC rapid charger, with its respective USB cable is also supplied (you can spot them by the green accents) that does a great job at quickly topping up the battery inside the OPPO HA-2.



As we mentioned with the occasion of our OPPO PM-1 headphone review, we have to say it again, just to get it out of the way: we have to confess that we’re not geared up to review audio hardware in a professional manner, so don’t expect to see in-depth frequency analysis, oscilloscope snaps, or other deeply technical aspects that would otherwise be part of an in-depth audio review on a dedicated website. We do love our music though, and we’ve got a few audiophiles on the team. Couple that with our admiration for the geeky stuff, as well as our living and breathing technology on a daily basis, and we’re confident you’ll can trust us.

We truly believe that your audio system, as a whole, portable or not, is as good as its weakest component/link. From proper sources to cables, from the AMP/DAC to your headphones, everything plays an important role, and you can only truly enjoy high-quality music, as an audiophile of aficionado, if you’re taking care of all the above.


As we mentioned in the sources section above, we shuffled quite a few things around, but mostly settled for what we thought offered the best experience: lossless FLAC files, played back alternatively from the Sony XPERIA Z5 Premium and iPhone 6s (when not playing from the iMac), digitally through OTG/USB, through the HA-2, to the OPPO PM-1 and Sennheiser HD800 (which sounded better to us that the other headphones we used during the test period).

Extreme detail is the word we’ll use for describing the performance of the OPPO HA-2. With the proper sources, even with songs you know by heart, you’ll definitely hear something you never thought was there before. From lows to highs, through mids and voice, it all sounds natural. In fact, it is so natural that at first it sounds a bit odd compared to the same song you used to listen to with a different setup, that most probably had exaggerations along its output or general performance.


Playing the exact same song with the same headphone connected directly to your smartphone pales in comparison, with no oomph whatsoever, lack of dynamics, details, and volume (mostly because of the smartphone’s own DAC and limited capability of driving demanding cans).

If you’re playing close attention, you can hear much more than the lows, mids, and highs. There’s a lot of sound and detail in-between, as present, as punchy, as dynamic as the artist intended it when recording. We had to flip the gain switch to high in order to accommodate our listening style; with smartphone source volume at around 75 percent and the OPPO HA-2 volume set to 3 or 4, we found it loud enough to scratch the limits of listening comfort. We couldn’t detect any distortions, aberrations, or exaggerations throughout the entire volume range.


Our listening style also required us to flip the Bass+ toggle to high. Not because having it on normal sounded dull, but because we the difference between the two settings is small, while definitely perceivable, and we liked the results better.



If you’re the average music consumer, you’ll likely want to skip this product. As an average music consumer, chances are that either your music library is in a lossy format (256kbps and below), or the headphones you’re using aren’t high-end enough; and, as we mentioned above, the entire system will be as good as its worst/weakest link.

However, if you’ve already invested in a high-end setup at your home or office, and you want to continue enjoying high-quality tunes while on the go, for $299, the OPPO HA-2 should definitely be on your shortlist of gadgets to check out this Holiday season. It is a product that we think is spot on from all perspectives that matter, with versatility, portability, and quality being the keywords.



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