Reviews of Attainable Hi-Fi & Home-Theater Equipment

Reviews of Attainable Hi-Fi & Home-Theater Equipment

Founded in Menlo Park, California, in 2004, Oppo Digital built its early reputation on its high-performance DVD players. It wasn’t until 2014, however, that Oppo began branching out into personal audio, with products like the PM1 headphones and the ultra-portable HA-2 DAC-headphone amplifier. I reviewed the HA-2 (since replaced by the HA-2SE), as well as Oppo’s PM-2 over-ear headphones (discontinued). Each product earned a Reviewers’ Choice award, and I bought the HA-2 review sample, which I’ve since replaced with an HA-2SE.

The new Sonica digital-to-analog converter ($799 USD) is Oppo’s only current DAC model, having replaced the HA-1 ($1199), which was introduced in 2014 and which Uday Reddy raved about on SoundStage! Xperience. Three years is a lifetime in the digital realm, and much has changed. The HA-1 was both a DAC and a high-quality headphone amp. With the Sonica, Oppo has, interestingly, dropped the headphone connection, despite the fact that they still make two headphone models. Instead, they’ve positioned the Sonica to be the ultimate affordable digital front end.

Oppo Digital Sonica

The Sonica measures 10”W x 3”H x 14.2”D, weighs a solid 10.4 pounds, and is available only in black. The case is a thin, sculpted aluminum shell on the top and sides, with a thick faceplate of brushed aluminum. Centered on the front panel is a 2.8” grayscale OLED display; to the screen’s right is a large Volume knob, and to its left a smaller Source knob that doubles as a pushbutton for navigating the Sonica’s menus. The only other things on the front panel are a small power button and a USB Type-A port, for storage devices such as USB thumb drives and DLNA servers.

On the rear panel are the usual suspects: coaxial, optical, and asynchronous USB digital inputs; balanced (XLR) and unbalanced (RCA) analog outputs; an Ethernet port and another USB Type-A port; input and output triggers; and an IEC power inlet and voltage switch. Also present are a ground post and an analog input (RCA), the latter funneling the incoming analog signal through the Sonica’s DAC section for an analog-to-digital-to-analog signal path. Purists will scoff, but I’m confident that plenty of listeners would prefer having the flexibility of an analog input without having to buy a separate preamp.

Oppo Digital Sonica

Inside are several stealth-black, custom circuit boards. The Sonica’s analog circuitry is fully balanced, from the built-in DAC straight through to the XLR outputs. Interestingly, the Sonica’s RCA outputs are converted from the balanced output. Both balanced and unbalanced outputs have identical technical specs: less than -115dB THD+noise at 1kHz, A-weighted; a signal/noise ratio of more than 120dB, A-weighted; and channel separation exceeding 120dB.

On the digital side, the Sonica’s chipset is ESS Technology’s new flagship, the ES9038Pro Sabre DAC, a monster of a chip whose 32-bit, eight-channel design boasts a THD+N of -122dB (0.00008%). The USB input can decode PCM signals of resolutions up through 32-bit/768kHz and DSD through DSD512; the coaxial and optical inputs are limited to 24/192 PCM and DSD64. DSD transmission is accomplished through DSD over PCM (DoP) v1.1. The Sonica supports the wireless formats Bluetooth 4.1, Apple AirPlay, and Wi-Fi up to 802.11ac.

Oppo Digital Sonica

While all of this is impressive for a component costing only $799, what endears me to the Sonica is its flexibility. Not only can it act as a fixed-output DAC, but its volume control operates in the digital domain, for maximum signal integrity. This control can also be activated for individual inputs, allowing for the Sonica to be integrated into a hi-fi system with a traditional analog preamplifier while also permitting variable output when, for instance, the optical input is engaged with a signal from your cable box.

It gets better. Many hi-fi apps I’ve used in the last few years have been functional but clunky, and some have been unresponsive. The Sonica’s dedicated app for Android and iOS devices is the best I’ve encountered. Setup was dead simple, regardless of whether I connected to the Sonica via Ethernet, Wi-Fi, AirPlay, or Bluetooth. Despite repeatedly trying to get the app to stumble, buffer, or just quit, the music kept playing, and the interface remained intact and responsive. While I wasn’t able to try it, the app also promises to seamlessly control one or more of Oppo’s wireless speakers, also named Sonica, giving users the ability to control multiple rooms’ worth of sound with a single reliable app. What seems a simple, fixed-output DAC can quickly become the control center for a whole-house music system.

Integrating the Sonica with Tidal’s streaming service was tight and clean, though I found that when I was 20 clicks deep into various searches, I had to click back 20 times to exit the Tidal interface and return to the Sonica’s main menu. It would have been swell to have a one-click return option, but that’s my only knock against an otherwise flawless software experience. That’s rare.

The Sonica’s remote-control handset is not included in the price; it’s a $29 option. That’s hardly a deal-breaker, especially in light of how smooth and reliable Oppo’s mobile app is. Still, I was a bit peeved when I needed to quickly adjust the volume or mute the Sonica, but couldn’t because I first had to turn my phone on, navigate to the Oppo app, and then issue my command. Including the remote as a stock accessory would be nice.


Given the Sonica’s reasonably small size, I began my listening by pairing it with the Schiit Audio Jotunheim DAC-headphone amp in my desktop system, connecting the two using Nordost Blue Heaven LS (XLR) cables. I wired the Sonica to my MacBook Pro laptop using a Nordost Blue Heaven LS USB link, but also streamed content via Wi-Fi, Bluetooth, and AirPlay directly from my iPhone 7, all through iTunes and Tidal. I wasn’t fond of the Sonica’s Bluetooth input -- it sounded a bit muddy and confused compared to the other options. I used NAD’s Viso HP50 over-ear headphones and PSB’s M4U 4 earphones during this time, and encountered nary a problem while using this setup.

Oppo Digital Sonica

But I spent most of my time listening to the Sonica with it installed in my main system of Hegel Music Systems H360 integrated amplifier and KEF R700 loudspeakers. Here I wired the Sonica directly to my network via Ethernet, and to the Hegel with Dynamique Audio’s Shadow (RCA) and, again, Nordost’s Blue Heaven LS (XLR) cables. I used the Sonica both as a fixed-output DAC, which allowed me to use the Hegel as an integrated amp, and as a variable-output DAC when connected to the Hegel's home-theater input. The Hegel was plugged into an Emotiva CMX-2 power conditioner, and connected to my KEF speakers with DH Labs Signature Q10 cables.


Soon after I donned my NAD HP50 headphones and began to stream music from Tidal using the Oppo app, I was liking what I heard from my desktop system. The Oppo Sonica is a good little DAC -- a broadly neutral device that produced clean sound unfettered, and was fairly revealing. Moreover, it sounded engaging, with a slightly sparkling treble. Consider Verses, from The Chopin Project, by Icelandic composer Ólafur Arnalds and German pianist Alice Sara Ott (16-bit/44.1kHz FLAC, Mercury Classics). The piece crescendos from a single, solemn cello to include the rest of a string quartet, the sound of each instrument layered atop the next. The sounds of the violins appear, one at a time, to either side of the cello, ebbing and flowing from background to foreground as each part, in turn, leads the work onward. While I could easily track each instrument as all of them “appeared” between my ears, the violins, played with vibrato, stood out from the mix, maintaining their natural rapidity and bite. Any more sibilant emphasis and the small strings would have turned hard and cutting; much less, and their intrinsic vibrancy would have been blunted. While the Sonica’s sound wasn’t perfectly linear through the treble, I was taken by the Oppo’s subtle contouring.

I then moved the Oppo into my main system, fixed its output, and wired it to my Hegel H360 integrated via the amp’s balanced XLR inputs. I cued up “Island in the Sun,” from Weezer’s third album (the green one), Weezer (16/44.1 ALAC, Geffen UICF1002), and was gratified to hear loads of texture and detail in lead singer River Cuomo’s infectious singing. The Sonica’s tonality through the midrange was excellent, re-creating Cuomo’s light, almost meek delivery with ease. His rough falsetto was easily intelligible, despite the busyness of the mix. Imaging was pretty good, with Cuomo planted squarely at the center of the soundstage and the strummed rhythm guitar to left and right of him. The sound in this song’s chorus is rough around the edges, with aggressive guitar chords that can be tough to make out, and the Sonica had some difficulty in trying to tease out finer details. It also fell short of maintaining total separation of instruments, with some slight spatial smearing compared to some of the top-flight digital front ends available. Alas, $799 can’t buy you the moon, but it may get you most of the way there.

Oppo Digital Sonica

When I played some of the trashy modern pop that so often gets my toe tapping -- Kygo’s latest single, “It Ain’t Me” (16/44.1 FLAC, Interscope) -- the Oppo’s presence region was on full display. Selena Gomez waxing poetic about an ex-lover with a fondness for heavy drinking doesn’t exactly strike me at my core, but her hotly mixed voice proved addictive through the Sonica. A strong sense of attack and decay allowed her voice to pop from between my KEF floorstanders with real intensity, highlighting the smoky quality of her voice. Punctuating the wistful lyrics are Kygo’s intoxicatingly atmospheric synthesizers and a punchy, driving bass line, all with an alluring sense of space due to the amount of reverb on display.

Replaying "It Ain't Me" with the Sonica run through my Hegel's home-theater input in variable-output mode removed a thin haze from the track. The sound was more immediate, with a considerable increase in jump factor. Gomez’s voice sounded sharper and more defined, dynamic contrasts increased overall, and the bass line felt more assertive and impactful. The overall effect was profound -- the affordable Sonica sounded far more incisive and revealing than it had minutes earlier with the same track.

The good times continued to roll with the Cars’ “Good Times Roll,” from The Cars (16/44.1 FLAC, Elektra). This 1978 recording has plenty of character -- the closely miked signature guitar riff in the right channel, the very audible noise floor, and lead singer Ric Ocasek’s opening lines sound as if they were recorded in a 20’-long metal garbage can. I was shocked at how well the Sonica re-created that space in my listening room. Closing my eyes, I “saw” Ocasek singing with a complete sense of ease, while the soft, lazy drum thwacks lent the track a warm, nostalgic ambiance. Admittedly, the Sonica didn’t exhibit the organic effortlessness of far more expensive DACs. If you want the nth degree of inner detail and analog-like effortlessness from your DAC, you’ll have to pay quite a bit more.


I reviewed Benchmark Media Systems’ DAC2 HGC ($1995) over four years ago, and my brother, fellow reviewer Erich Wetzel, wound up buying my review sample. The DAC-preamp-headphone-amp was brilliant back then, and despite the march of time, continues to be so. Like the Oppo Sonica, the DAC2 HGC uses a Sabre Reference chipset, albeit the previous-generation 9018. Also like the Sonica, the DAC2 has USB, optical, and coaxial inputs; RCA analog inputs; and XLR and RCA analog outputs. A key difference, however, is the Benchmark’s inclusion of a traditional analog preamplifier anchored by a custom-made Alps volume potentiometer. In practice, this meant that while the Benchmark could directly drive my Hegel H360’s amp section, it did so with its own preamp, as opposed to the Oppo’s effectively lossless digital volume control.

These differences in hardware made little difference in the sound: the Benchmark and Oppo DACs sounded remarkably similar. As I replayed the tracks mentioned above through the DAC2, the word that sprang to mind was vibrant -- each track rang through my KEFs with more finesse than when the Sonica was at work. Selena Gomez’s voice in “It Ain’t Me” had more texture, and while just as well hewn as before, it felt less hard at the fringes, more delicate. Track after track, the Benchmark reinforced this impression -- I found the sound through the DAC2 more compelling, evoking in me more of an emotional response, than it did through the Oppo.

Oppo Digital Sonica

But these shortcomings were only small blemishes on the Oppo’s sonic résumé, which otherwise stacked up well against the Benchmark’s. Each had a crystalline quality through the treble, and an unassailable tonality through the midrange. The Sonica doesn’t include the DAC2’s excellent headphone amp, but makes up for it with multiple wireless inputs, streaming capability, and greater flexibility. It’s remarkable how far digital processing has come in the last few years.


Oppo Digital’s Sonica DAC can serve as a lovely digital centerpiece for the systems of progressive audiophiles. It offered terrific sound quality when partnered with a high-quality power amp, and still quite good sound when used as a traditional, fixed-level DAC. In short, it always provided exciting, engaging sound. What makes the Sonica exceptional is its pliability. This little guy can slot with ease into almost any setup: wired or wireless, streaming or local, lossy or hi-rez. That ease can’t be overemphasized: A fussy mobile app can make an otherwise exemplary product a burden to live with, but the Sonica delivers ease of use. Oppo’s done it again.

. . . Hans Wetzel

Associated Equipment

  • Speakers -- KEF R700
  • Earphones and headphones -- NAD Viso HP50, PSB M4U 4
  • Integrated amplifier -- Hegel Music Systems H360
  • DAC-headphone amplifier -- Oppo Digital HA-2SE, Schiit Audio Jotunheim
  • Digital-to-analog converter -- Benchmark Media Systems DAC2 HGC
  • Source -- Apple MacBook Pro laptop computer running Tidal and Roon 
  • Speaker cables -- DH Labs Q-10 Signature, Dynamique Audio Caparo
  • Analog interconnects -- Dynamique Audio Shadow (RCA), Nordost Blue Heaven LS (XLR)
  • Digital interconnect -- DH Labs Silversonic
  • Power conditioner -- Emotiva CMX-2

Oppo Digital Sonica Digital-to-Analog Converter
Price: $799 USD.
Warranty: Two years parts and labor.

Oppo Digital, Inc.
2629B Terminal Blvd.
Mountain View, CA 94043
Phone: (650) 961-1118