Audio Streams

Playback options include a draggable track-progress bar, the standard play/pause, forward, and back buttons, and repeat and shuffle modes. If you swipe the current song's album-cover art, you're presented with its metadata, including its bit depth and sample rate. Overall, I found the Sony app relatively intuitive and easy to use.

Sound
"Autumn Leaves," from Duke Ellington's Indigos and featuring singer Ozzie Bailey (5.6MHz DSD, Columbia/High Definition Tape Transfers), is some seriously silky-smooth goodness. This 1957 stereo recording is like honey for the ears, and the Sony delivered just about every last ounce. If the NW-ZX2 had one overriding quality, it was clarity. It dug very deep into this recording's depths, readily communicating every bit of microdetail, nuance, and fine-grained resolution while retaining a very convincing grasp on the overall sound picture.

Through my NAD Viso HP50 and trusty old Audio-Technica ATH-W1000 headphones, the NW-ZX2 dispensed gobs of well-controlled bass, enough that something like Caribou's Our Love (24/96, Merge) sounded appropriately big and badass. There was also plenty of drive and dynamic slam—the music not only moved, it was moving, making it difficult for me to sit or stand still. During Our Love, I clicked through all of Sony's Surround Sound profiles; while they certainly shifted the EQ to offer different views on the recording, I found that I preferred my music straight, no chaser.

But while the NW-ZX2 had a nice amount of tone color, I've heard music delivered with more body and color. The PonoPlayer ($399), with digital and analog circuits designed by Ayre Acoustics, has such a meaty and more colorful sound; especially in balanced mode, it can make a recording like The Freewheelin' Bob Dylan (2.8MHz DSD, Columbia/Acoustic Sounds) sound less thin. That meatier midrange does come at the expense of some of the perceived detail that the Sony dug out, so personal preference and the headphones used will make one player "better" than the other. In terms of pairings, I found the NAD HP50s better partners for the NW-ZX2—the Audio-Technicas themselves tend toward the bright and the lean.

Assuming that some readers use their portable players as part of their hi-fis, I lashed the Sony to my Pass Labs INT-30A integrated amplifier with a length of AudioQuest Victoria interconnect. Frank Sinatra's In the Wee Small Hours (2.8MHz DSD, Capitol/Acoustic Sounds) sounded just lovely through my DeVore Fidelity The Nines: smooth, silky, refined—and sad. The relative thinness I'd heard through headphones was audible here as well; I've heard more robust, more meaty sound from other players, such as the Pono. Of course, you can adjust the Sony's EQ settings, boosting or reducing to your heart's content, but tone color is not something I've found you can EQ in or out of a component's basic sound.

Back to my NAD HP50s. I played all manner of music through the NW-ZX2, including CD-quality sources, which could sound just lovely. Most of my digital files are of CD-quality, and I have no problems enjoying it daily. An old favorite, Don Cherry's Art Deco (CD rip, A&M), a superb-sounding recording engineered by Rudy Van Gelder, was all blurt and sizzle, as it should be. Cherry's pocket trumpet has a very distinct sound, and Billy Higgins rides his cymbals all over the place—the Sony did an excellent job of delivering the minute details of both. I've heard James Clay's tenor sax reproduced with more weight and a heavier helping of body, but overall, the Sony's sound was crisp, clean, and dynamically lively.

I know there are those whose attention is not held by CD-quality sound, but I'm not one of them. On the other hand, I don't often listen to lossily compressed music, which I find irritating over time. My library contains only a handful of MP3s, and they're there only because there's no other way to hear those recordings. One such track is the scrumptious and sexy live version of PJ Harvey and Björk singing the Rolling Stones' "Satisfaction" (look it up on YouTube, it's more than worth it). While this track can sound muddy and dull—it's a 128kbps MP3—the Sony NW-ZX2, with ClearAudio+ engaged, cleaned it up enough to provide a much more enjoyable listen. I can see how people with large libraries of less-than-ideal–sounding, lossily compressed music would appreciate the Sony's ability to deliver a more musical sound.

All of the recent wrestling in the "popular press" over lossy compression vs CD-quality vs hi-rez strikes me as nothing more than a bunch of intellectual (at best) puffery. In reality, you'd be hard-pressed to buy an audio device with a DAC that does not support hi-rez audio. The only real holdouts are some smartphones and Apple. But if you're happy with your iPhone and lossy compression, more power to you. Those of us interested in bettering our musical experiences, even when using our portable devices, are blessed with an abundance of choices in all price ranges. And for Sony's new Walkman, there's the rub.

How does one differentiate oneself in a field already crowded with the likes of FiiO, Pono, LH Labs, Astell&Kern, HiFiMAN, and more? Of course, there's sound quality, and the Sony NW-ZX2 delivered a healthy helping of it. Then there are features. I have little interest in an audio device that replicates some of the functions provided by my smartphone. I don't go anywhere without my phone, so there's no need to duplicate such services as e-mail, calendars, etc.—but that's just me. Nor am I a big fan of EQing or adding DSP special sauce to my music—again, more a matter of personal taste than of absolute judgment. I imagine that those who have lots of recordings of less-than-ideal quality (eg, MP3s) will see the NW-ZX2's various sound-enhancement options, including DSEE HX and ClearAudio+, as pluses.

And there's price. At $1199.99, the NW-ZX2 is not inexpensive. Nor is it the most expensive portable player. The Astell&Kern AK240, which I reviewed in the November 2014 issue, holds that distinction at $2500, and while it's been a while since the AK240 left my premises, I'd say that it offers a bit more finesse, a bit more body, a bit more sweetness in the upper frequencies than the Sony. The AK240's build quality and industrial design are a notch higher, and it can function as a DAC and USB-to-TosLink converter—features that may influence a purchase decision one way or another.

In the NW-ZX2's favor are its DLNA and WiFi capabilities, which add to its appeal when used at home. Its ability to play music from my NAS-based library is a huge plus that I took great advantage of during the Sony's stay. Another appealing in-home feature is the Sony's Bluetooth circuit. I have Audioengine's B1 Bluetooth receiver here for review—I paired it with the NW-ZX2 to stream music to my main hi-fi, something that took all of two seconds. While Bluetooth is lossy, I find that its convenience factor outweighs any sonic penalties, especially as any friend with a smartphone can hook up to my hi-fi and be wirelessly playing their music through it in seconds.

Does the Sony Walk the Walk?
Sony's NW-ZX2 High-Resolution Walkman has a lot going for it, including very clean, incisive, lively sound with a good helping of well-controlled, well-rounded bass. I enjoyed using it to listen through a goodly amount of my music library, both stored on the Sony itself as well as streamed via WiFi from my NAS, and from hi-rez to CD-quality to even a few MP3 files. There are other options out there, but take a close look at the features and functions the Sony offers; if they match your needs, put the NW-ZX2 on your "listen to" list.