Eighteen months ago we looked at the first portable audio player from Questyle, a prestige Chinese audiophile company. We were very impressed with the sound of the QP1R, although it had a couple of usability issues. Now the QP2R has been released, and not only have all those issues been addressed, its performance has been enhanced by support for even more audio formats.

HB2 Hi-Fi Hub System

HB2 Hi-Fi Hub System
Along with this latest version of its high-res portable player, Questyle has released the HB2 Hi-Fi Hub System, which allows far easier use of the unit’s high-quality replay when you’re back at home. It docks the QP2R and can charge it (though stops charging while playing), and
it comes with a convenient physical remote control allowing playback and menu navigation from a distance.

The Hub does not incorporate a DAC itself, rather extending the outputs of the QP2R into the RCA connections most useful as inputs to hi-fi systems, and in the settings menus you can choose whether the Hub will output as digital or analogue. In design terms it follows the cues of the QP2R, also protecting against vibration by using solid aircraft-grade aluminium together with a special silicone material supporting the player and on the base. As a system the HB2 has just landed itself an iF 2018 Design Award, and the price to add this to your QP2R is $999.

Equipment
To recap the actual player, then, this is an iPod Classic-style music player. Unlike many of the competitors, there’s no Android in there (although the specs say its operating system is based on Linux), no Wi-Fi, no apps. It plays music — that’s its purpose.

Nor is there a touch screen. Its 60mm colour screen is for display of artwork and information, and to show the various menus. You navigate and control play with a number of soft and hard keys. On the front is an iPod Classic-style click-wheel with an enter button at its centre. You put a finger on this and rotate. As with the previous model, there are four touch-sensitive controls arrayed around this: a context menu at top left, return at top right, and track skip left and right at the bottom. Our complaint last time was that you had to wake the player up to use these keys, such as the track skip or play/pause. That usually involved two distinct presses of the key.
But in this model Questyle has added three physical keys to the left edge: play/pause, skip forwards, skip reverse. These operate instantly at all times, except, of course, when the player is switched off entirely. A power key on the right edge wakes it back up again. It takes about 20 seconds to be ready to play.

While we’re on controls, let’s not forget the hefty milled volume knob on top. It adjusts to turn the volume up when rotated clockwise if you’re looking down from the top — and if that seems wrong to you when viewing from the front (because you’re moving the face of the knob to the left), no matter — a setting allows you to reverse its direction. You can also switch off the soft skip keys, which I found useful because I brushed them a little too frequently.

The player plays everything: MP3, WMA, OGG, APE, AAC for lossily compressed stuff; WAV, FLAC, ALAC, AIFF, DFF and DSF for lossless. DSF and DFF are Direct Stream Digital, of course, and regular DSD64, plus DSD128 and DSD256 are handled. Likewise for the PCM-based formats, sample rates up to 384kHz are supported. The player uses an AKM AK4490 DAC, changed from the Cirrus Logic one in the previous model. The headphone amplifier is Questyle’s particular forte, and if I may be permitted to repeat a paragraph from our QP1R review, its DAC “feeds an amplifier designed and built based on the university work of Questyle’s founder and CEO, Wang Fengshuo. This is a pure Class-A current-mode amplifier, offering extremely wide bandwidth and low transient intermodulation distortion. An output impedance of just 0.15 ohms means that even with low impedance headphones (models down to eight ohms are supported), variations in their internal impedance for different frequencies will have no effect on performance.”

There’s a lot more to it than that, mind you. For example, you have access to adjust the bias setting for the Class-A circuit.

All this is built into a chassis machined from aircraft-grade alloy. The review unit was finished in a gentle gold colour, but a silver grey option is also available. The dark front and back panels are made from Corning Gorilla Glass for strength. The click wheel matches the chassis.
Power is provided by a 3100mAh Lithium Polymer battery, rated at ten hours of operation.

There’s 64GB of storage built in, with a single microSD card slots to add more. This is rated at cards of up to 200GB in size, which are now more readily available (albeit at prices around $150 for reputable brands from reputable retailers); I used a fast 128GB microSD card. Loading nearly 4000 tracks, all FLAC or DSD, many of them high resolution, used up about 85% of the space available across internal memory and the card I used. If you’re prepare to make do with one of the lesser formats, you’d be looking at a capacity of tens of thousands of tracks. Or you can take a bundle of cards and swap them in and out for an effectively unlimited library, but do note that they’ll have to be indexed on insertion (see below).

The previous model had two outputs: a 3.5mm headphone socket and a 3.5mm line output, which also featured optical digital audio. The latter has been dropped and replaced with a 2.5mm socket for balanced headphones. The optical output is now in the headphone socket. An optical 3.5mm-to-Toslink adaptor is included with the player. As with the last model, both sockets are indented into the chassis. We complained that one of the cutouts was too small to accommodate our cables. That’s changed, with both cutouts now 12.9mm in diameter, which ought to be big enough for all but the strangest cables.

Charging and communications are via a USB Type-C socket, another welcome improvement over the Micro-B USB of the previous model (the reversible cable is far easier to insert). You get a cable with the player (one was not included with the review unit, but I have my own), along with a cloth pouch, a quick start guide (the manual can be downloaded from Questyle’s web site), the aforementioned optical cable adaptor, plus silicon discs to place on the click wheel (Questyle calls it a ‘steering wheel’) and the OK button for easier operation. Those last two weren’t included with the review unit so I haven’t assessed them.

Finally, as mentioned above, there’s a HB2 Hub available as an extra, which is like a power stand for the Questyle QP2R with outputs suitable for connection to a hi-fi system, and with a physical remote control as well. 

Performance
When I received the review unit, the firmware was at 1.0.2. The Questyle website had an update to 1.0.3. As usual, I want to have the most up to date version installed for the purposes of review. I’d just note that the update file was compressed in .rar format rather than the much more common .zip format. Zip has been natively supported by Windows for 20 years, and by MacOS for 15 yewars, whereas for .rar many will need to find and install some unpacking software. I already had some on my computer, because that’s the kind of person I am, but many won’t.

I note that on Questyle’s website the previous QP1R’s most recent firmware update is 1.0.9 (I reviewed it at 1.0.4). So it seems that Questyle keeps issuing regular improvements, for which it is to be applauded.

Copying across music to the internal memory proceeded, according to the Windows 10 copy dialogue, at about 8MB/s, or USB 2.0 speeds. To copy around 734 tracks amounting to 41GB to the player’s internal memory took an hour and 25 minutes. There’s nothing you can do about that speed (the USB 3.0 port I use on my computer will copy data at well over ten times that speed to memory cards that are fast enough), though if you use a fast microSD card and reader, you could load up your card externally to get through it much more quickly.

Once loaded, the library will need to be updated through the settings menu. There is an automatic setting, but it reindexes everything after any time the unit has been plugged into a computer — it doesn’t just search for new tracks. It’s fairly fast but I preferred to leave it on manual so I could control when it happened. Speed: for the 3859 tracks of mixed FLAC standard and high resolution and DSD (note I use a fast microSD card, too) it took two minutes and ten seconds.

I spent many, many hours listening. Or, rather, enjoying music, using the Questyle QP2R as the source device. The sound was glorious through the several different sets of headphones I used (all unbalanced, and with impedances from 16 to 150 ohms). Even my old Sennheiser HD 535 headphones, were easily driven to unlistenably high levels by the QP2R. There was never once the slightest hint of clipping, or even of a forced sound.

Maximum output level is one thing, gain is another. One recording I use for this is an early Telarc release, the Ozawa/Silverstein/Boston Symphony rendition of Vivaldi’s ‘The Four Seasons’, recorded digitally in 1981 on a 50kHz, 16-bit Soundstream tape recorder. For whatever reason, this was captured at a very low level. The Allegro of Spring — one of the louder sections — peaks at -9.77dBFS, and averages at less than -32dB. It’s quiet. I guess they wanted to make sure there was plenty of headroom.

It was touch and go, but even with this recording and the old Sennheiser* headphones, satisfying levels were delivered. With modern headphones — such as the Oppo PM3 headphones with which I did most of my listening — thunderous levels are available even from this track.

Bass control was first class. Detail and resolution? First class. Noise? None at all, other that what might be on the recording. Dynamics were delivered with a lifelike feel. There was no category of music that was short-changed by the player.

There’s a gapless play setting, and this kind of worked with my test FLAC tracks, albeit still with a slight audible catch right at the boundary between tracks, rather than the smoother melding the best implementations can manage.

LEFT: QP2R output frequency response for CD quality and high-res signals (see main text for details). RIGHT: Signs of clipping at high levels into a low impedance (15.9 ohms).

My measurements revealed that the device produced ample power for all reasonable, and some quite unreasonable, headphones and earphones. At the highest gain setting the output delivered 1.8 volts RMS into a line-level load (47,000 ohms) using a sine wave test signal that peaks at 0dB FS. Into a high impedance headphone load (a fake one, a purely resistive 295 ohms) it still delivered 1.8 volts RMS, for an output of 11 milliwatts. That’s a couple more than the 9mW Questyle claims, and is sufficient to deliver 10.4dB more output than the sensitivity rating of the high impedance headphones in use (assuming they use the dB for 1mW measure). In practice, it was ample.

Into a low impedance — 15.9 ohms — the output is limited by clipping, rather than gain. On the volume scale from 0 to 60, it went into clipping at 53. The graphic (above right) shows 1002Hz at volume setting 52 (unclipped), 53 and 54. It’s an inelegant look, but I can’t see anyone ever experiencing it. That’s because with the volume setting of 62, the output into 15.9 ohms was a bit over 31mW, which means that 16 ohm headphones will deliver some 15dB more output than their rated sensitivity.

With 24-bit, 96kHz test signals the player delivered a gentle roll-off starting just above 10kHz to be down by 0.5dB at 20kHz, 1.25dB at 30kHz and 2.75dB at 40kHz. A-weighted noise was an impressive -107.1dB. THD was 0.0010% and IMD 0.0021%. Cross-talk was at -105dB. All those figures push deviations from perfection far below the level of human perception. With 192kHz sampling, the performance was essentially identical in every way, including the roll-off at the high end, except that the output continued beyond the Fs/2 for 96kHz. It was at -5dB at 50kHz, at -8.5dB at 60kHz and nearly -13dB at 70kHz. It’s all very gentle (left graphs above).

Into a high impedance load, with 16 bit 44.1kHz test signals the unit managed -97.4dB A-weighted noise, and 0.0011% THD and 0.0041% IM distortion. The response was down by 0.3dB at 20,000 hertz and took a sharp downturn almost immediately above that. Into 15.9 ohms, the noise level was still better than -95dB and the frequency response unaltered. Combined with a calculated output impedance of around 0.3 ohms, this unit’s performance should not be affected by the headphones in use.

Conclusion
The Questyle QP2R isn’t cheap, and some Android-based players we’re reviewed offer more flexibility of use. But if it’s superb musical performance in a stylish package you’re after, the QP2R is most certainly worth checking out, especially with the additional utility conferred by that optional Hub for the home. 

Questyle QP2R
Price: $1999

+ Super performance
+ Stylish looks
+ Supports just about every audio type, even 11.2MHz DSD

- Gapless performance could be improved

Tested with firmware: 1.0.3
Display: 60mm colour screen
Storage: 64GB internal, 1 x microSD slot (up to 200GB)
Outputs: 1 x 3.5mm headphone/optical digital audio, 1 x 2.5mm balanced headphone
HB2 Hub outputs: SPDIF out (RCA), analogue RCA
Other: 1 x USB Type-C
Dimensions (whd): 66 x 134 x 15mm
Weight: 206 grams
Optional HB2 Hub price: $999
Contact: Audio Dynamics Pty Ltd
Telephone: 03 9882 0372
Web: audiodynamics.com.au