From The Absolute Sound by Steven Stone
Although Questyle may be a new name to some audiophiles, the company has been in existence for several years. It combines two complementary operations: Questyle Audio Technology Co. Ltd, China, and Questyle North America Inc., USA. All Questyle products are manufactured by its “strategy partner manufacturing center,” Foxconn, which also makes many Apple products.
The component under review, the Questyle QP1R portable music player, was in development for over three years. Questyle’s goal was “to make it possible for true music lovers and professional audiophiles to enjoy the same hi-fi listening experience achieved in state-of-the-art home-based systems in a portable body.”
Questyle has two versions of its portable player. The standard QP1 lists for $599, while the QP1R lists for $899. According to Questyle, the QP1R uses higher-quality components as well as a more critical approach to the audio circuit. The QP1R also produces lower distortion; the QP1R’s THD+N is 0.0006%, while the QP1 THD+N is 0.0015%. The QP1R also employs a different PCBA, a larger internal storage chip (32GB), and a different version of its operating software.
The unique technological feature of Questyle digital products is their patented “current mode amplification” Class A output circuitry. This circuit originally appeared in Questyle’s flagship headphone amplifier, the CMA800. Jason Wang, the CEO and chief designer for Questyle, developed the first current-mode circuit in 2004, while he was working on a communications circuit project in school. The first prototype had a bandwidth of 1MHz!
After graduation Wang went to work for an IC design firm where he continued to refine his current-mode amplification design with the help of several mentors, including Dr. Charles from the University of California, Los Angeles. The CMA800, the world’s first current-mode headphone amplifier, was introduced in 2007. With the CMA800, Wang solved the technology issue of how to mass-produce the current-mode circuit using discrete components, and the Questyle brand was born.
In the current-mode amplifier, transistors amplify the signal’s current via a circuit operating in a pure Class A. The output stage can be either a Class A or AB voltage amplifier. The CMA design reduces capacitance between the transistors so the circuit operates at a very low impedance, which improves the speed and full-power capabilities of the entire amplifier. The current-mode amp also employs a negative feedback loop that is hundreds of times faster than that of conventional voltage amplifiers. This CMA circuitry not only vastly reduces transient intermodulation distortion; it also contributes to wider overall bandwidth.
On the digital side, the QP1R uses a three-clock integrated circuit with FIFO asynchronous structure and three voltage-stabilized power stages. The QP1R employs Cirrus Logic’s flagship DAC chips (CS4398), along with a customized clock from NDK with phase noise lower than -150dB. Other premium parts in the QP1R include power inductors from Wurth, an ALPS encoder, and Nichicon F95 tantalum capacitors.
The QP1R chassis is milled out of a solid piece of aluminum and merged with a Gorilla Glass front and back, which not only reduces the QP1R’s overall weight but also provides a better environment for EMI sensitive circuits.
Some portable players, such as the Sony NW-ZX2, are basically smartphones without the phone part, and with the capability to support other functions, such as streaming from the Internet or serving as a USB DAC. But the QP1R is not a multi-function device. Its primary and principal function is to play back digital music files located in its internal memory or on removable microSD cards. Its feature set is very much like the Astell&Kern AK Jr ($499), except that the QP1R plays all formats natively without converting the DSD to PCM or PCM to DSD. The QP1R can also drive a wider range of headphones optimally due to its three gain-level options.
The Questyle QP1R has two slots for microSD cards, located on either side of the micro-USB connection on its base. Currently the QP1R supports high-speed cards up to 200GB, giving it a total capacity of 432GB. If you need more storage to carry your entire music library, all you need to do is purchase and populate additional microSD cards. When you connect the QP1R to a Mac, its microSD cards are recognized as individual drives, as is its internal memory of 32GB. Populating cards with music was easy—I merely dragged and dropped the files onto the microSD cards. Transfer time was the same as for other USB 2.0 storage devices.
I used the QP1R with a wide variety of headphones and in-ear monitors. Depending on the headphone’s impedance and sensitivity I employed all three of the different gain settings—low, medium, and high. The least efficient and power–hungry headphones on my shelf, the Beyerdynamic DT-990 600-ohm version, needed the high-gain setting and got to 40 on the 0-to-60 volume scale. At the opposite extreme, the very efficient and sensitive Westone ES-5 only needed a volume level of 23 in low-gain mode to play loudly. There was the faintest amount of hiss from the Westone ES-5s when the QP1R was in pause. The vast majority of my reference headphones were best served by the middle or medium-gain setting.
In addition to a single-ended mini-stereo-plug headphone output, the QP1R also has a second line-level analog output connector that doubles as a TosLink digital output. Although I doubt that many QP1R users will feel the desperate need to use the TosLink connection to feed an alternative DAC, it could come in handy to feed a second system or to transfer data without resorting to the analog output.
Ergonomics and Everyday Use
Customer units are supplied with a cable for charging and data transfer, a soft carrying bag, TosLink adapter, and an analog line-level cable. Since soft-cloth bags don’t do much to protect stuff, I found that the iDream365 hard protective case ($9.68 on Amazon) was the perfect size to serve as a zippered travel case for the QP1R—there’s even room for some spare microSD cards.
The QP1R weighs 6.5 ounces, making it heavier than a smartphone, but not by much. Unlike some of the bulkier portable players, such as the Colorfly C-4, no amount of bicep crunches using the QP1R will pump you up. Despite its light weight, the aluminum chassis feels rock-solid. The attention to finish on the QP1R rivals any portable player I’ve seen regardless of price—every edge is precisely beveled, including the edges of the small wake/sleep button on the side of the chassis.
On the subject of buttons, the QP1R’s control layout is unique among portable players, except perhaps for the iPod Classic. Like the iPod, the QP1R uses a wheel with a central “enter” button. This wheel lets you scroll through menus and once you’ve gotten to the right selection, pushing the button activates your choice. In addition the QP1R has four touch-sensitive activation points that surround the wheel. They will take you to either the home page, last selection, or the next or previous song.
The QP1R does not have a touch-sensitive screen. I know that some people love touchscreens, but on portable devices they can be more trouble than they are worth—it gets tiresome to have to constantly lock and unlock your screen, and an unlocked touchscreen in your pocket is not a great idea unless you are a devotee of John Cage randomness.
The volume knob on the QP1R is located at the top of the chassis, protected Panerai-style by guards on either side. It turns smoothly through its scale of 0 to 60. And while there were times when I wished it would respond faster, when I wanted to turn the volume down quickly, it was glitch-free. Turning the knob clockwise (looking down at the top of the player) brings the volume up and counter-clockwise brings the volume down.
Another unique feature in the QP1R player is its “vibrate mode.” When this setting is activated (it’s also the default), if the QP1R wakes up from sleep, turns on, or acknowledges a command (such as “pause”), the entire chassis vibrates briefly. The first time this happens will surprise you, but after the novelty wears off it may seem somewhat silly. I suppose if you need to be able to operate the QP1R’s controls while the unit is still in your pocket, out of sight, the vibration will serve as a confirmation that something will happen, soon. Fortunately you can turn off the feature, which will also increase your battery life.
Speaking of power, the 3300 mAh li-polymer battery has a published playing time of between eight and ten hours. If you play primarily high-resolution files, the duration will be on the shorter end of the spectrum. Even with eight to ten hours of projected runtime, I would advise carrying an extra USB battery along for international trips.
For users who prefer to tailor their sound, the QP1R offers two user-configurable-and-saveable eq settings, EQ1 and EQ2. Users have up to 6dB + or – adjustments at 31Hz, 62Hz, 125Hz, 250Hz, 1k, 2k, 4k, 8k, and 16kHz. The eq controls are located in the system settings, which require several button-pushes to locate. If you are a compulsive eq-alterer this could get tiresome, but for those who set and then forget about eq this arrangement works fine.
Gorilla Glass has a neat name, and is known for its hardness, which is a fine attribute for a portable device. But Gorilla Glass is also extremely slick, so slick that if you hold the QP1R in your palm and slant your hand even slightly downwards, the QP1R will inevitably begin to slide out. While the QP1R’s chassis and glass look as if they could survive a drop or two without any ill effects, I’d prefer not to find out.
When it comes to portable players, describing their intrinsic sonic character is difficult. That’s because their sonic personality is a result of the combination of the player and the earphones connected to it. Yes, I know that’s obvious, but what is less obvious and far more empirical, is how a particular player’s own impedance and power-handling characteristics will interact with a headphone’s impedance and sonic personality.
Perhaps it’s a function of Questyle’s current-mode amplification circuit, but I found the QP1R to be among the least fussy portable players when it came to headphone pairing. Even the more idiosyncratic headphones in my collection, such as the Sennheiser HD 700, which can sound “peaky” with some portable headphone amps and players, sounded smooth and controlled. While I was still aware of the HD700’s sonic personality, its positive sonic characteristics were moved to the forefront by the QP1R, while its amusical faults were minimized. The QP1R can handle a wide variety of headphones successfully while letting the basic personality of the cans show through.
Audiophiles who don’t care for headphones often cite the lack of a conventional three-dimensional stereo image as a barrier to their enjoyment. Headphone devotees, on the other hand, can go to great lengths expounding upon the imaging differences between various headphones. When I first began to listen to headphones I was in the former camp, but as time passed I’ve learned how to listen through headphones and decode the imaging information. For me the “imaging breakthrough” came one evening while I was monitoring a live recording using Ultimate Ears In-Ear Reference Monitors. I was using a single stereo pair of microphones and during the show it was easy to imagine that instead of listening through earphones my head was where the microphones were. Listening to that recording today through the QP1R via in-ear monitors puts me right back in that moment again.
Comparing the QP1R to every other player within a couple of hundred dollars of its $899 price would fill up at least several pages, so I will focus on the players with which I have had long-term personal experience. First up, the Astell&Kern AK Jr that I mentioned earlier in the review. The QP1R is more flexible in terms of headphones it can drive optimally and music it can play without conversion. And while the two players are similar in function (they are both music file players, not USB DACs), the QP1R has wider applicability for everyday use.
Moving up the price ladder, the $999 Calyx M has more versatility since it can also function as a USB DAC. The Calyx has shorter battery life—five to six hours versus the QP1R’s eight or nine hours. The Calyx is slightly quieter with sensitive in-ear monitors—even the Westone ES-5 was silent and hiss-free. At the other end of the headphone spectrum the Calyx didn’t have quite as much drive power as the QP1R with Beyerdynamic DT 990 600-ohms. Sonically I felt the midbass on the Calyx was a bit warmer and more prominent. Both players generated equally sized soundstages.
Comparing the $1199 Sony NW-ZX2 with the QP1R was a bit like apples and oranges feature-wise. The Sony’s open-architecture Android operating system lets you add apps just like you would with a smartphone as well as stream from Internet sources, including Tidal. As a stand-alone player the Sony doesn’t have the ability to drive as many demanding headphones as the QP1R, but on sensitive in-ears the Sony and Questyle generated equal amounts of low-level hiss when connected to the Westone ES-5s. With easy-to-drive headphones such as the Oppo PM-3 or Audeze EL-8 the two players sounded identical, but with harder to drive headphones such as the Audeze LCD-2 and Beyerdynamic DT990 600-ohm version I’ve mentioned, the QP1R proved to be a better option due its higher output and superior drive capabilities.
Currently a seventh-generation iPod Classic 160 will set you back slightly less than $400. And while on paper the iPod has the same functionality as the Questyle QP1R, it lacks the expandable storage, the ability to play higher-resolution PCM and DSD files, and the capacity to drive a wide variety of headphones. So, when your iPod Classic finally dies and ascends to the big Apple in the sky, I would enthusiastically recommend moving up to the Questyle QP1R instead of purchasing another iPod.
With its impeccable sound quality, flexible storage, and ability to drive a wide variety of headphones the Questyle QP1R ranks among the best portable players I’ve heard. The Questyle QP1R’s shortcomings are that it is only a portable player. It is not a portable USB DAC or USB-to-SPDIF converter. If you require more functionality, there are many other options, but if your primary requirement is for excellent sound in a robust and well-designed portable player, the Questyle QP1R should be at the top of your audition list.
SPECS & PRICING
Frequency response: 20Hz–20 kHz, +/-0.1dB
High-gain settings: Max output, 1.9V RMS
Middle-gain settings: Max output, 1V
Low-gain settings: Max output, 0.53V RMS
DAC: Cirrus Logic CS4398
Output: 3.5 mm headphone output, 3.5 mm line out & optical output
Sample rate: PCM: 44.1kHz-–192kHz (16-bit/24-bit), DSD64, and DSD128
Support: AAC, ALAC, APE, AIFF, ADPCM, DFF, DSF, FLAC, LPCM, MP3, OGG, WAV, WMA, WMA Lossless
Storage: Up to 288GB (32GB internal and two 200GB microSDXC card slots)
Battery: 3300mAh li-polymer, 8–10 hours
Operating system: Linux
Body: CNC aluminum case.
Display screen: 2.35″ IPS (400×360) LCD screen Gorilla Glass front and back
Dimensions: 5″ x 2 5/8″ x 9/16″
Weight: Approximately 6.5 ounces