Greece Media HXOS: CMA800i DAC with Amplifier Review

Media:Greece HXOS

Reviewer:Mr. Yannis Kamarinos

Questyle CMA800i

True DSD Current Mode Amplification "3 in 1"

Perhaps they do not have a two-digit number of years in the field of High Fidelity, but Questyle is fast, with a strong view and research background.

I expected other things and other things occurred during the test, dear readers. For while the creation of Questyle’s CMA800i, is placed in the category 'Headphone Amplifier with integrated DAC ", it can serve as the" brains "of a whole system, from the inclusion of the preamplifier. A system whose unique sources will be our computer via the USB port, and CD transport or a media player, via the coaxial input, or a desktop system of active speakers or amplifier and speakers…this is purely a matter of choice. What matters is that Questyle, with a few years of presence in the area of High Fidelity, has a way to bring twists on how we strengthen the signal. And their way has a name: Current Mode Amplification.

The designer Mr. Wang Fengshuo, initially started from a young age with booster stage constructions and concerns on the introduction of distortion in the signal negative feedback circuits, when he was in the University laboratories. The fight against this phenomenon, known as the electronic «transient intermodulation distortion» (TIMD - transient intermodulation distortion), was the main axis of the search of an alternative pathway of signal amplification. Thanks to a combination of luck, knowledge and subtlety, a wrong design of student work, eventually led (after years of research) to the patented circuit based on his implementations, under the proprietary umbrella of Questyle.

In summary, the Chinese designer developed a voltage amplifier circuit in the final stages (input-output) with two intermediate power stages. The intermediate stages operating in class A, and the final signal is A / AB class as he support. He adds negative feedback, low resistance, which in combination with the rapidity of the circuit eliminates the possibility of TIMD as he characteristically mentions. Of course, he not only stayed on this undoubtedly remarkable achievement in developing the circuit. He worked four consecutive years up to attain what for him is «High-End sound." Leaving no detail to chance, from the accessories to the wall thickness and to dimensions of the chassis.

Inside we find only quality materials, such as capacitors and WIMA Nichicon, military-grade resistances DALE, Neutrik receptors, toroidal transformer Canadian Plitron ... The motorize potentiometer is ALPS 27. The section of the DAC based on the top chip Wolfson WM8741 while remaining integrated they have printing of Questyle. The digital part "endowed" with two filters), FIR and IIR while USB is an asynchronous three timing clocks. In the analog section, dual output for headphones and PreOut implemented through distinct pathways. The user can choose to support the aluminum, 10mm thick chassis with three or four legs !. And there is a small remote control.

The facade is simple and has the selectors and input filter and the volume potentiometer. In the center position the two outputs 6,5mm headphone. But the back is richer. The signal has outputs via either XLR, or RCA and there coaxial output. Similarly there is a coaxial input and USB input, also offered is a pair of analog inputs.


Having read the basic principles governing the manufacturer's philosophy (and the headphone amplifier tests CMA800), we must mention that the new design meets the expectations that give birth to the technical specifications. Thus, the upper area was what first make a difference: extensive presence of excellent harmonics and total lack of "metal sound", to the extent that it points to very good tube implementation!

The middle area is for the eloquence of tone colors and the plasticity of description. Human voices have the required brightness and precision, assisted by a very dense "information grid" developed by the CMA800i, enhancing the realism of interpretations. Instruments developed in the mid range, will occur with fullness or rougher depending on the recording. The vacuum tube microphones recordings of jazz 60s discs will find a valuable (digital) helper, which also applies to the distorted guitars of modern metal producers. The common element of the two, diametrically opposite sounds, is the creation of a strong frontal scene with extensive dimensions.

Here we should mention that the design rapidly responds to changes in dynamic range, the requirements of rhythmic sections and the behavior of the phases, as reflected in the processing of records. And this elementental catalyst of the entire spectrum, is what helps most in the low range. Combine that with the emergence of individual details, and you get a headset pair with very good low. You hear electric and acoustic bass, as you probably have not heard it before. Raise the volume and your system with three way speakers will be tested on whether it can control an extensive and detailed low frequency information. Be careful, however, because while our device can come down very low, it is not one that will throw a "punch in the stomach", at least not a devastating one. Select a more gentle, more delicate presence, certainly free of distortion, which assists in the purity of the signal and the operation of the dynamics. Something that is very evident in DSD recordings. Especially those carried out as such. For example the «Haydn String Quartets vol. 2 'from the Amsterdam String Quartet and «Mahler Symphonies n6» from Festival Budapest Orchestra (both from Channel Classics).

True DSD

The promise of reproduction of DSD files in their original format and not by converting them into PCM or via DoP operation is equally (with the aid methodology) an attractive feature. The Questyle combines TrueDSD operation with the player JRiver, for PC users. For the purposes of the test, the laptop Toshiba Satellite (Win7 Premium) was installed with JRiver 21 and the manufacturer's instructions were followed. Lo and behold, playback DSD files resulted in the shift to the right the indicator led. But it had another consequence, the change of the sound character of the CMA800i! While hearing PCM signals, either from files or through the transport, the created scene had sufficient range all along the spectrum, and prominently 'muscular' description instruments and voices, the "DSD" situation brought to the fore more gentle character, with audible lower noise threshold, and more clearly highlighted the breaths and pauses among the score punctuation. The audio stage has receded substantially behind the plane of the speakers, extending far in depth. The sense of depth was enlarged along with the stage dimensions, and with the use of headphones.

It is intriguing at this point with the fact that when asked to reproduce JRiver list with mixed files (DSD and PCM), the DAC stayed "locked" in place "DSD", even without changing the sonic behavior! That is, the PCM files benefited from a more "refined" way the CMA800i treats DSD. Posing the question in Questyle, the answer concerned sto ASIO. Creates, supports the company, a new ASIO connection, high data throughput between JRiver and CMA800i.

We do not support that CMA800i plays best through the DSD route, it just plays different. And the comparison that immediately followed, with intense lyricism projects like the Anastasis Dead Can Dance (flac file), did not produce a winner. The scene was described finest in «DSD», the impressive voices of the great performers have stronger body in «PCM» ...It was therefore a matter of preference what aesthetic would be adopted.


Undoubtedly, Questyle has expertise that has a direct, audible impact on the reproduction of music. And this is what makes them friends everywhere in High Fidelity circles to talk about their implementations, especially on the other side of the Atlantic, rushing to procure the most distinguished of them, such as portable QP1R, the headphone amplifier CMA800R and the DAC 192. It is most likely that the CMA800i will follow the same successful path since it contains three devices in one, at an attractive price, even for our dismal economic situation. If there are no requirements in number of inputs, this design that fits into the small chassis, produces "big" sound, tailored to the requirements of modern music lovers. While several audio engineers have chosen the reinforcing Questyle for their headphones, though aesthetically different from "war tools" for the studio, such as the embodiments of the Burson etc It reminded me very strongly of the combining precision and lyricism of the Italian Norma Acoustics. Plus DSD Playback.

However one sees it, Mr. Wang Fengshuo believes in what he does and supports it at the academic and research levels. It is worth while to reward him.


01. Installing JRiver and regulation to leave DSD signal, an easy process. Only this platform fully exploits the capabilities of CMA800i.

02. The designer supports the use of IIR filter, in order to eliminate the phenomenon of pre-ringing. The filters are deactivated when introducing the device in position «True DSD».

03. With 7,5Vrms a headphone output, it is hard to find a load that the CMA800i can’t handle.


-Extremely Interesting theoretical and constructive approach.

-"Analog" high, lyricism, extended stage.

-Speed, silence, dynamics, effectiveness.

-Discrete headphone output circuit and preamplifier.


-The PC users are required to install JRiver.

-The Display absence and ergonomic options limit the possibilities as a pure preamplifier.

-Many will judge the bass as 'soft' if they do not give it the required listening time.


The Questyle approach is a classic example of the philosophy of the Far East. Commitment and internal search, until what would appear to be as comprehensive as possible. It is no coincidence that Mr. Wang worked for four years (2008-12) the Current Mode Amplification, before the commercial launch and having already had conceived and researched the original idea for many consecutive years. Perhaps it is not coincidental that began the Year of the Rat and appeared to the fore the Year of the Dragon!


TYPE: DAC, headphone amplifier, preamplifier

INPUTS: USB, coaxial

OUTPUTS: 2x6,5mm (jack), RCA, XLR, coax

GAIN: 11,8dB

POWER OF HEADPHONES: max. 180m/7.5Vrms@300Ω


S / N: 118dB (headphones),> 107dB (pre)

OPERATING: WinXP / 7/8/10 / vista (32 / 64bit), MacOSX 10.5.7


DIMENSIONS: 330x300x55 mm


PRICE: 2.599 EUR

Home  /Evaluation >> Greece Media HXOS: CMA800i DAC with Amplifier Review

Hot news

All right reserved.2015 备案号:粤ICP备15014720号-1  
旷世科技 | Questyle Audio 2016