Five Portable Hi-Res DACs Compared Oppo HA-2 Amp/DAC

Oppo HA-2 Amp/DAC


PRICE $299

Slim shirt-pocket form factor
Resolution up to 394/32 plus DSD
Not an ideal match for Oppo’s own headphones

The Oppo HA-2 sounds fabulous, supports digital connections for a wide range of smartphones, and can even charge a phone.

Oppo’s Blu-ray players are reference-quality, and the company’s planar headphones are winning positive reviews. The HA-2 is the more portable of their two amp/DACs.

To handle this slim leather-sheathed beauty is to love it. About the size of a smartphone, it’s just a half-inch thick, not terribly heavy, and shirt-pocket-friendly. A cylindrical knob for power and volume is at top left. Headphone and combination line in/out jacks are on top. On the right side are pinpoint power indicators and switches for bass boost and headphone gain. The bottom includes USB A and Micro-B ports plus a three-way input switch that selects either of the two USB digital inputs or the analog input.


The HA-2 handles file resolutions up to 384-kHz/32-bit plus DSD. While there are few if any 384/32 commercial downloads, internal processing with 32-bit depth prevents software volume controls from reducing dynamic range or truncating bits. As always, Windows driver installation is required for files over 96/24. Volume control of USB sources is mapped onto the DAC chip, which can then adjust volume without use of a bit-truncating DSP. Twiddling the grippy, knurled volume knob for further adjustments is a pleasure.



The Class AB amp runs on battery power for non-computer sources. It is specified to play for 13 hours with analog input or 7 hours with digital input, and it charges in 90 minutes with the supplied power adapter (or longer via computer USB jack). The battery can charge connected smartphones. Supplied cables include analog, USB Micro-B, and Apple Lightning/USB A.

Sennheiser’s cans consistently flattered the Oppo. The two aced the lossy tracks, making the best of low-bit-rate Ramones and Jorma and beating every other roundup combo in their control of Sandy’s steely wail and Dvořák’s orchestral swells. Among the CD-quality tracks, Marianne’s voice was well integrated with the church ambience, Teddy’s edgily recorded vocals made “perfect sense now!,” and Yes was lavished with “beautiful, irresistible flow, listenable but not too laid-back or dumbed-down.” Oppo/Senn didn’t lose steam in the hi-res tracks: Nataly’s challenging peak was “fatigue-free,” and the Saint-Saëns—whose organ/orchestral weaponry demands to be played loud—had that elusive “hi-res ease.”


Ironically, the Oppo amp/DAC was less consistent with the Oppo headphone, at least on my test tracks; maybe the thick, darkish voicing of both was too much of a good thing. True, they were “best case for lossy” on the Ramones and downplayed the lossy artifacts on Jorma’s acoustic guitar. They also minimized the hardness of Dvořák’s peaks and Teddy’s vocals. But they “rolled off” Sandy’s guitarists, “took the sparkle and chime” out of Yes guitarist Steve Howe’s 12-string acoustic, and “downplayed” textures in the Saint-Saëns—though the Ali Akbar Khan raga was “fully realized,” with the sitar rising out of the haze like a metallic dragon.

The Oppo did OK with the often tetchy Sony headphone on the low-bit-rate lossy tracks, and considering how forthrightly the Sony reveals lossy artifacts, that’s actually high praise. As resolution climbed to CD-quality, Yes’ 12-string guitar harmonics were “a delight,” even if the mellotron was “a little hot,” and other tracks were good if not exceptional. If Marianne had “less depth” and Bach was “dry,” that was mostly the headphone. But peak moments in Nataly and Saint-Saëns induced discomfort.

The Oppo HA-2 is beautifully designed and thrives with neutrally voiced headphones. It tells the truth, with a subtle spin, often superbly.

Dimensions (WxHxD, Inches): 2.7 x 6.2 x 0.5
Weight (Ounces): 6.2
Inputs: USB A (1), USB Micro-B (1), 1/8-inch analog
Outputs: 1/8-inch analog headphone (1), 1/8-inch stereo line (1)
Output Power: 300 mW, 16 ohms; 220 mW, 32 ohms; 30 mW, 300 ohms
Output Voltage: Up to 3 V RMS
Output Impedance: 0.5 ohms
Compatible Headphone Impedances: 16 to 300 ohms
Sampling Rates and Bit Depths: 44.1-384 kHz, 16/24/32-bit, DSD 64-128-256
Upsampling: Limited (chip operates at 100 MHz)
DAC: Sabre ES9018-K2M
Windows Drivers Installed: ASIO

Oppo Digital
(650) 961-1118

buckchester's picture

I’d like to share my experience.

I bought a Schiit Asgard 2 headphone amp and Schiit Modi DAC last year, based largely on Steve’s reviews.Pairing them with headphones that are adequately powered through a normal laptop or MP3 player, I’m very hard pressed to notice a difference (Grado SR225i and Audio Technica M50x).To know for sure, I would have to be able to instantaneously switch back and forth between my laptop’s headphone jack and the Schiit rig.By quickly plugging my headphone jack out of my laptop and into the Schiit rig I’m unable to say (with certainty) if there is any difference in the sound quality.Yes people, it’s that close.

I also have a pair of Hifiman HE-400i headphones.I definitely notice an improvement with these when they are plugged into the Schiit rig, but that’s because theses headphones benefit from the extra power.

So, unless you have headphones that require extra power to achieve your desired volume, I wouldn’t bother with a headphone amp.I wouldn’t bother with a stand-alone DAC at all.

I’d like to see Steve do some reviews of equipment like this doing blind ABX testing.It would be interesting to see if he could pass the tests.,3733-19.html

Mark Fleischmann's picture
I can't speak for Steve Guttenberg but I was the author of this DAC-amp roundup. I see that your experience of DAC-amps is limited to one manufacturer. You might want to try a few different ones before deciding that it doesn't make a difference. The five products in this roundup had points of similarity, but depending on content, there were also some significant differences. Thanks for your comment -- and please continue evaluating things independently based on your own experience. All readers should do the same!