The 2015 T.H.E. Show in Southern California clashed with my having to be in the office to ship our August issue to the printer, so I wasn't able to attend. But in devouring the online coverage on www.stereophile.com and its sister sites, on InnerFidelity.com I found a report by Tyll Hertsens about two new hi-rez portable players that made their debuts at T.H.E. Show: Questyle Audio Technology's QP1 ($599) and QP1R ($899).

Questyle was a name new to me. The company, based in China, has its products manufactured by Foxconn, of iPhone fame, but its North American operation is headed up by Bruce Ball, a veteran of the high-end audio industry. The two new players are very similar, differing in internal storage capacity—the QP1 has 16GB, the QP1R 32GB—and, according to Questyle, the QP1R uses higher-quality components and different firmware, and offers lower distortion and superior sound quality.

As much as I love the sound of the Pono Music PonoPlayer that I bought to replace the Astell&Kern AK100 on my daily commute, its Toblerone size and shape mean that it won't fit in my shirt pocket—and in New York City's summer swelter, I don't wear a jacket with a pocket into which I can slip it. The slim Questyle players looked tempting. I felt I should review the affordable QP1, but my baser instincts got the better of me—I asked for a sample of . . .

The QP1R
The size of a pack of cigarettes, the QP1R is housed in a CNC-machined aluminum chassis with a gray or a gold anodized finish. The front and rear panels are made from iPhone-esque Gorilla Glass, the front dominated by a square, color LCD screen and metal scroll wheel. This wheel has a central pushbutton and, around its circumference, four touchbuttons; a button on the QP1R's right edge acts as both the On/Off switch (long push) and disables/enables the control wheel, buttons, and the displays (short push).

The wheel's central button acts a Play/Pause control as well as a Select button, while the four other buttons—labeled Home, Return, Right, and Left—allow the settings menus and music library to be navigated in conjunction with the scroll wheel.

On the QP1R's top edge are two 3.5mm jacks. The left-hand jack is for headphones, the right-hand one for both analog (line level) and digital (optical S/PDIF) outputs. The line output can be set for fixed or variable level. To the right of the jacks is a conventional rotary volume control, protected by extensions of the aluminum frame. As supplied, there were two choices for maximum gain, High and Low, but with the latest firmware (HW v.4 and SW v.1.02), released during the review period, there are now three gain settings, to allow the player's output be optimized for specific headphones. The output impedance is specified as 0.15 ohm, which means the QP1R should have no problem driving even low-impedance in-ear monitors. The latest firmware also implements two independent octave-band graphic equalizers. As these offer up to ±6dB of adjustment, activating each drops the overall volume by 6dB, to avoid digital clipping.

The player's base has a micro-USB port flanked by two slots, each of which will accept a microSD card of up to 128GB capacity, for a maximum storage of 288GB. Questyle recommends FAT32-formatted cards, but I had no problems with an exFAT-formatted 64GB card. The micro-USB port allows the QP1R's 3300mAh lithium-polymer battery to be charged by a host computer (no AC adapter is supplied). Charging is said to take eight hours from a USB port.

The QP1R supports the regular PCM file formats—ALAC, APE, FLAC, AIFF, WAV, WMA Lossless—up to 24 bits and 192kHz. It also supports both DSD64 and DSD128 files, in DFF and DSF formats. The DAC chip is a Cirrus Logic CS4398, which features a combined multibit delta-sigma architecture operating up to 192kHz. The CS4398 handles DSD data natively, according to its datasheet, and is the same chip used in Astell&Kern's well-regarded AK240 portable media player.

Questyle says that the QP1R has three voltage-stabilized power stages, and that its headphone amplifier features a patented current-mode topology with discrete devices biased into class-A. (The player did get warm after playing continually for an hour or so.) Operating in current mode is said to offer low noise and very wide closed-loop bandwidth, even after the application of negative feedback. Having learned my electrical engineering in The Age of Tubes, which are voltage-mode devices, I have never been able to get my head around current-mode circuits, so I will have to take Questyle's claims on trust. It's what it sounds like that matters.

Use
Loading both the QP1R's internal memory and the microSD cards is a simple matter of connecting the player to a host computer and drag'n'dropping the audio files onto the respective desktop icons. When the icons are ejected in the usual manner and the USB connection is broken, the player automatically scans its storage and rebuilds its music library. (There is also a manual option for doing this.)

Questyle claims a battery life of up to 10 hours, which seemed about right. The QP1R has a tactile feedback feature that I found invaluable: Whenever one of its buttons is pushed, the player vibrates briefly. However, I had some problems with both the scroll wheel and the touchbuttons. Using the QP1R in the office, with it lying on the desk next to my keyboard, the wheel and buttons would respond only intermittently. I found I had to hold the player to get consistent operation. But I loved the multilevel Return button, which got me quickly back to the Now Playing screen after I'd been adjusting, say, the equalizer settings.

Listening
I found the QP1R's graphic equalizer useful with the AudioQuest NightHawk headphones, which Herb Reichert reviews in this issue's "Gramophone Dreams" column. To sound neutral, these 'phones benefited from a slight, +2dB boost at 8Hz and above, and an equally slight cut at 62Hz and below. My Audeze LCD-X and Ultimate Ears 18 Pro headphones were okay with the Questyle's equalizer disabled, however. The following comments are an amalgam of my experience with all three headphones.

Consistent throughout my auditioning of the QP1R was a sense of ease to the sound, coupled with clarity. I never got the feeling that recorded detail was being unnaturally spotlit, but I could hear deep into recordings. Alto saxophonist Paul Desmond's clam in the second verse of "Blue Rondo à la Turk," from the Dave Brubeck Quartet's Time Out (DSD64 file, CBS Legacy/Acoustic Sounds), was more audible than I'm used to—I have never understood why this take was used for the master (footnote 1), given this problem, nor have I read anyone commenting on it. Similarly, there's a clumsy high-register trill on the concertino trumpet in the first movement of Bach's Brandenburg Concerto 2, performed a whole step lower than concert pitch by the Academy of Ancient Music, directed from the harpsichord by Richard Egarr (24/88.2 ALAC file from Harmonia Mundi HMU 807461.62). This had been one of my 2010 Records to Die For," but I hadn't been aware of the problem with the trill until I listened to it with the Questyle player driving the Ultimate Ears in-ear monitors. Now, of course, I hear it all the time, no matter what gear I'm using.

The QP1R dug deep into recorded acoustics. My favorite set of the complete Beethoven Violin Sonatas is by Augustin Dumay accompanied by Maria João Pires, which we made our "Recording of the Month" for February 2003. In the Sonata 10 in G, Op.96 (ALAC rip from CD, Deutsche Grammophon 471 495-2), Dumay's violin sounds as if recorded in a smaller, drier hall than was Pires's piano. By contrast, playing the performance of this sonata by violinist David Abel and pianist Julie Steinberg (24/192k needle drop from Wilson Audio W-8315), our "Recording of the Month" for February 1984, through the Questyle revealed that while Abel and Steinberg were closer to the mikes, both instruments were clearly being played and recorded in the same space. But with both recordings, the QP1R got the tonalities of the instruments correct.

Catching the PBS broadcast of Simon and Garfunkel's Concert in Central Park, from 1981, during Pledge Week reminded me that it had been a while since I'd played Paul Simon's 2012 album, Live in New York City (16/44.1 ALAC files ripped from CD, Hear Music). This is possibly the best live band Simon ever put together, with guitarist/saxophonist Mark Stewart acting as music director and the extraordinary multi-instrumentalist Jim Oblon on drums. And while the late Phil Ramone couldn't resist the pressure to mix this album loud, listening to bass guitarist Bakithi Kumalo reprising his part in "Diamonds on the Soles of Her Shoes" with the Questyle driving the Audeze headphones was as good as it gets. The bass had the right combination of articulation and weight to its sound.

The song premiered, of course, on Graceland, and in 2012 I'd bought the 25th-anniversary reissue (24/96 ALAC file, Warner Bros./HDtracks). In general, I was disappointed at how this classic album, too, had fallen victim to the Loudness Wars. Given that the people who would buy this edition would be old farts like me, who loved the original's openness of sound and lack of overall compression, why was it felt necessary to reduce its dynamic range for the reissue? But an unexpected bonus on this edition was the demo version of "Diamonds on the Soles of Her Shoes," with Kumalo's virtuosic bass line front and center under the voices in the deconstructed mix. Again, with the Questyle, this was as good as headphone listening can get.

But as impressed as I was with the QP1R, it was time to hear how it stacked up against the other portable hi-rez products I've reviewed.

Against the Aurender Flow
Last June, when I reviewed the Flow D/A headphone amplifier ($1295), I liked its sound a lot, but felt that its light tonal balance would be a better match with relatively dark-sounding headphones like the Audeze LCD-Xes than with headphones, such as Sennheiser's HD-800, that have a similar character in the treble. As the Flow has a TosLink input, it would be easy to compare it with the QP1R, using an optical cable to drive the Flow from the latter's optical S/PDIF output and switching the LCD-X headphones from the player to the DAC.

Or so I thought. It turned out that the Questyle's Line and Headphone outputs can't be operated in parallel—inserting the TosLink cable in the Line Output mutes the QP1R's Headphone output. The first ¼"-to-3.5mm adapter cable I tried to use with the Audezes was fouled by the flange around the Questyle's output jack, meaning it played in mono unless I held it in place—and every time I unplugged the headphones from the Flow, the latter's volume was reset to "0."

But once I'd worked out how to overcome those operational difficulties, I could compare the two, matching the levels by ear. Using the 24/176.4k AIFF file of David Abel and Julie Steinberg's recording of Brahms's Violin Sonata 1 (Wilson Audiophile)—I was pleased to find that the QP1R's TosLink output did operate at this sample rate—the Questyle's and Aurender's treble balances sounded very similar. The piano's low frequencies had slightly less weight through the QP1R, a touch more authority through the Flow. This was with the LCD-X headphones.

Through the AudioQuest NightHawk headphones, the Aurender's low-frequency weight with "Heart Is a Drum," from Beck's Morning Phase (24/96 ALAC file, Capitol/HDtracks), became too much of a good thing. Even with the EQ bypassed, the Questyle's lighter lows allowed me to hear a bit deeper into the mix with this bass-heavy track, although, paradoxically, I ended up preferring "Lose Yourself to Dance," from Daft Punk's Random Access Memories (24/88.2 ALAC file, Columbia/HDtracks), through the Flow, which had a tad more midrange presence.

Against the Astell&Kern AK100
The first high-end portable player I reviewed was the Astell&Kern AK100 ($699), which I wrote about in August 2013 and subsequently purchased. Through the Audeze LCD-X headphones, Beck's "Heart Is a Drum" sounded lighter in weight with the A&K than with the Questyle. This may well be due to the first-generation AK100 having a higher source impedance, though this character added to the player's sense of low-frequency articulation. More important, the midrange was more fleshed out with the Questyle QP1R, Beck's voice sounding better separated from the other instruments in the mix. The Questyle's top octave also seemed slightly more extended when I switched to the NightHawks.

Against the PonoPlayer
I reviewed the PonoPlayer ($399) in April 2015. Sticking with the NightHawks in conventional single-ended mode, the double bass in Dave Brubeck's "Three to Get Ready," from Time Out (DSD64 file, Columbia/Acoustic Sounds), had a touch more low-frequency weight through the Questyle than through the Pono, though the Pono reproduced the piano with more midrange body. The instrument sounded slightly more ethereal with the QP1R, though the hint of room acoustic around the stabbed piano chords just before the final statement of the theme was more developed with the Questyle. In "All or Nothing At All," from Diana Krall's Love Scenes (DSD64 file, Verve/Acoustic Sounds), Krall's voice sounded a little more three-dimensional through the Pono, though again, the double bass with which she duets at the start of the track had a bit more low-frequency weight through the Questyle.

With Beck's "Heart Is a Drum," the Pono sounded too thick in the upper bass, the Questyle doing a slightly better job of delineating the individual elements in this complex mix. This was with the AudioQuest NightHawk headphones; the more open-sounding Audeze LCD-Xes worked better with the PonoPlayer, though the Questyle still had greater low-frequency weight with these headphones.

Conclusion
I enjoyed my time with the Questyle QP1R, though I never got entirely comfortable controlling the player with its scroll wheel. And with the slightly-less-than-optimal performance at the top and bottom of its dynamic-range envelope (see "Measurements"), users should make sure they use the gain setting most appropriate for their specific headphones. But the QP1R is beautiful in appearance, and equally beautiful in sound quality with both hi-rez PCM and DSD files—I can confidently recommend it. And unlike the PonoPlayer, it does fit in my shirt pocket. Just.