StereoNET: Questyle Golden Reference Review

MAY 2017

QUESTYLE AUDIO THE ULTIMATE HEADPHONE LISTENING COMBINATION

REVIEW / QUESTYLE / CMA800P / CAS192D / CMA800R

QUESTYLE

QUESTYLE AUDIO THE ULTIMATE HEADPHONE LISTENING COMBINATION CMA800P Preamplifier, $5,199 CAS192D Digital-to-Analogue Converter, $4,299 CMA800R Headphone Stereo / Mono Amplifier, $4,299 (each)

From a very young age, Wang Fengshuo (Jason Wang) was always passionate about music and electronics. He was seven years old when he had his first HiFi listening experience.

From that moment he was hooked.

He eventually majored in Electronics Engineering, at university. He became fixated with the notion that the current standards and designs in audio amplification systems were not perfect and wondered what more there might be.

Whilst working on current-mode communication circuits, he built a device for an experiment. It wasn’t built correctly, and so wasn’t fit for purpose. But it wasn’t a complete failure however, as Wang realised that the device he had built was capable of high speed audio amplification via currentmode, instead of typical voltage amplification.

He persevered. Most students love their

“its unusual engineering principles and approach to audio have earned the brand a fast climb into the audiophile world”

time off during the summer, but not Wang.

Instead of going home over the 2004 Summer

holidays, he and his team worked tirelessly

Online message boards have long since

After eyeing what’s become known as the

to determine the true potential of current-

debated the positives and negatives of

“Gold Stack” at Melbourne’s Tivoli HiFi, the

mode audio amplification. Whilst a few audio

different implementations of current-mode

staff were generous enough to loan us what is

companies had used current-mode for

amplification. There are a select few that

currently the flagship offering from Questyle: an

audio transmission, it had not yet been used

worship the idea of fast-slew rate. Some even

entire stack of the brand’s top-end goodies.

for amplification.

say that our usual gripes with damping factor

That summer, the first current-mode audio amplifier was born.

Since its inception, current-mode amplification has seen little to no use in the manufacturing world; most brands stick to the traditional means of voltage-amplification that we know and love.

As Wang spent years pursuing his passion, audiophiles sat up and took notice of his achievements with his unusual amplification systems. He began by selling his creations out of his own home. In 2012, such success meant he could no longer handle the demand for the amplifier by himself anymore, and the Questyle Audio brand was born.

and output impedance are no longer an issue.

The stack consists of a DSD DAC, a pre-amp, and two balanced amplifiers. Each of them

While Questyle has only been around for a

is the reference “Golden” edition. The main

few years, its unusual engineering principles

difference (other than the sexy exterior colour),

and approach to audio have earned the

is the PCB inside, which is a custom-built

brand a fast climb into the audiophile world.

ceramic unit from Roberts.

They made quite a splash with the QP1R portable player in the Head-Fi and Portable Audio scene, and have earned the company’s stripes accordingly.

Let’s start from the top.

CAS192D DIGITAL-TOANALOGUE CONVERTER The CAS 192D is the flagship current-mode

Questyle claim that a lot of run-of-the-mill

filters add to the impulse wave, making the

DAC from Questyle and it’s also the first link in

DSD DACs will convert to PCM before piping

music sound incoherent and unnatural. The

this very unique chain.

the audio through the outputs, whereas with

Questyle Audio CAS192D offers the more

this DAC (and use of the proprietary driver,

advanced IIR digital filter, which completely

software package and filtering), DSD files will

eliminates the pre-ring from the impulse wave

never be converted to PCM before they reach

producing a more natural sound,” A Questyle

the headphones.

spokesperson said.

It boasts a solid aluminium chassis, CNC machined by Foxconn. The size, dimensions and materials are the same across the entire range covered in this review. The entire casing is hefty and thick, and Questyle claim this

There are a few other goodies packed into

offers control of sympathetic vibration, and

the unit, such as 3 x asynchronous clocks, 2

excellent shielding of RFI/EMI radiation.

x upsampling clocks, a pretty serious power supply, and the famous Wolfson WM8741

The front of the device offers a single colour

DAC chip for PCM playback (used in products

LCD display and four buttons. At the rear,

such as the Audio-gd NFB-2.1 and the ALO

there is an array of inputs including optical,

Continental dual mono DAC/Amp).

coax, and USB - one of each. Outputs include balanced XLR and unbalanced RCA. Despite the unassuming exterior, there are a few neat tricks that separate this DAC from the pack.

Also, Questyle has an upgraded FIR filter claiming: “Currently the majority of DACs use FIR (finite impulse response) digital filters, but research

Primarily is the DAC’s ability to decode

and testing has shown that our ears are

“True DSD”, as opposed to DSD over PCM.

very sensitive to the pre-ring that FIR digital

“There is deep and unique functionality for those who seek it”

In Use After booting this unit up, the user is greeted

The CAS192D was simple enough to use,

with a splash screen. It will take a few seconds

and happily provided both balanced and

to prepare itself, and perform internal testing. It

unbalanced signal at the same time.

will then flash “ready to use” on the display.

The unit will stay active even when in

Setup wasn’t complicated - but required a

“standby” mode, which was a little puzzling,

specific driver to be downloaded from the

as we had to keep telling our PC that the DAC

Questyle Audio website. For PCM and general

had been switched off.

playback, we found that any software was happy to be compatible with the DAC directly.

It’s a neat device that does exactly what it says on the tin. There is deep and unique

For “True DSD” playback, we had to download

functionality for those who seek it, and unique

Jriver Media Center. Installation was a breeze,

internal design philosophy, but fairly useful

and the CAS192D and JRMC talk seamlessly

features as well.

once they are both up and running. We have been told that JRMC is required for DSD playback, but were unable to test if other software packages would work.

Considering its extensive I/O possibilities, the DAC would be just at home in a high-end HiFi systems as it is in a dedicated Head-Fi rig.

CMA800P PREAMPLIFIER Interestingly, the flagship current-mode

At the rear of the unit, inputs include 1 x

preamplifier from Questyle was originally

balanced input (2 x XLR) and 1 x unbalanced

designed and commissioned for STAX,

input (2 x RCA), along with 1 x balanced

specifically for their flagship SR-009

output (2 x XLR) and 1 x unbalanced output

Electrostatic Earspeakers.

(2 x XLR).

Originally unveiled in May of 2014 at the

It’s convenient to be able to quickly switch

Munich High End show, Stax proved its

between a balanced solid state preamp

support of this preamp by providing an entire

and a tube preamp for sound comparisons.

SR-009 system to be displayed with the

The switching is seamless with no delay, so

CMA800P for the launch.

once both sources are volume matched, the

Physically, the CMA800P is cut from the

comparisons were made simple.

same cloth that that the CAS192D DAC

During our listening tests, the CMA800P was

is, with a similar weight, the same physical

a top performer. Even at lower volumes, there

dimensions, and a familiar aesthetic all the

were no channel imbalance issues, and no

way down to the aluminium casing, which

clicks or pops when selecting sources which

was selected by Questyle to maintain proper

you would expect from a high-end product.

temperature control).

To my ears, the CMA800P provided no

But, that’s where the similarities between

colouration to the sound at all. It faithfully

the two products end. The front panel of the

amplified any source input (balanced or

CMA800P is simple: one giant knob for input

unbalanced), and left the sound basically

selection, another for volume, and some LED

untouched. It provided clean, undistorted and

lights to display the current input selections.

raw amplification, a perfect match for the pair

The CMA800P is a highly versatile preamp, and with an array of inputs and outputs.

of CMA800R amplifiers that we had paired with it.

“the CMA800P provided no colouration to the sound at all”

CMA800R HEADPHONE STEREO / MONO AMPLIFIER The final link of the chain in the ‘Gold Stack’,

CMA800Rs into “Mono” mode, putting each

a headphone wired into its very own full-size

the CMA800R is the flagship headphone

one into a “Mono Full Balanced” configuration,

amplifier is really something to savour.

amplifier from Questyle Audio.

effectively bridging them in a “Dual Mono” set

Much like the CAS192D DAC and the

up,” a Questsyle spokesperson said.

There are pitfalls however. Any existing 4-pin balanced headphone cables will not be

CMA800P, it also utilises Questyle’s Current

Effectively, it means that Questyle recommend

compatible. Again, Tivoli HiFi was generous

Mode amplification system.

having two of these amplifiers paired together

enough to loan me a specific cable for my

to create one combined output, which is

Audeze headphones, but unfortunately my

exactly what we did for our listening.

Sennheiser HD800S balanced cable was not

The CMA800R features a razor- flat frequency response from 5hz to a number far greater than multiple times the limit of human hearing.

It also claims to be the first headphone amplifier in the world to offer “Mono Full Balanced” output.

Interestingly, instead of using a standard 4-pin balanced headphone socket to plug into, we instead found a generic 3-pin XLR instead. The reason behind this, according to Questyle is: “To create a proper balanced output, a stereo amp is required for each channel. Rather than compromise by using a transformer or resistors, Questyle takes advantage of this by allowing you to switch two Questyle Audio

There are both positives and negatives to

compatible with this amplifier at all.

this. The immediately obvious positive is that

It also has to be mentioned that the idea of

the full mono balanced configuration delivers

having to own two CMA800Rs to achieve

four times the power that a single CMA800R

balanced amplification may be a slightly

would deliver in unbalanced mode. There

difficult pill to swallow for some, especially

is also individual channel control of left and

when compared to the many alternative

right channels, while having two completely

balanced amplifier options on the market.

separate mono amplifiers guarantees complete channel separation.

The compatible headphone cables for this configuration are fascinating. Rather than a single cable, there’s actually two XLR cables combined together; one for each driver of the headphones. Having each individual driver of

Ultimately though, all this comes down to just one question. How does it all sound?

Whilst I quickly discovered it’s best not suited for sensitive IEM use, it does scale well over a range of different headphones and driver types.

Impressions with Audeze LCD 2

Impressions with Sennheiser HD800S

With the use of a mini-XLR to full-size XLR

Noteworthy is that the “800” in the amplifier’s

headphone cable which was compatible with

model number is because it was designed

the balanced output of the CMA800R, we

with driving Sennheiser HD800 headphones

were able to make the planar connection.

in mind. Luckily, we had a pair of HD800S

I found it best to keep the amplifiers at full

headphones from Sennheiser on-hand to test.

volume, and to adjust the preamp output as a

Whilst not as notoriously fussy as its younger

volume adjustment.

sibling (HD800), the Sennheiser HD800S

The power-thirsty planars were easily satisfied, and there was more than enough headroom to spare.

The accuracy that I found during testing with the HD800S was present here again and the true nature of the LCD 2 was brought into the light once more. Bass was full, flowing, and deep-reaching. Vocals were smooth, and

is still quite demanding when it comes to amplification. Thankfully, the CMA800R is more than happy to come to the party.

The characteristics of the headphone could be heard with absolute clarity. There were no audible issues with damping, no detectable colouration of the sound, and no bloating in the bass.

without piercing treble; the headphones were

Tonal accuracy was spot on. The voicing

being heard exactly as they were supposed to.

ability of the headphones was brought to full

The LCD 2 were powered faithfully, and with

light.

plenty of headroom. There were no hints of

The matching with the HD800S was

distortion, no wonky frequency dips, and no

phenomenal. A pairing that I believe may even

signs of the headphone being underpowered.

rival Sennheiser’s own HDVD800.

Another great matching.

Details and stereo separation were some of the best I’ve have ever heard this headphone produce. The imaging and soundstage were simply immaculate.

If you’ve been searching for the perfect matching amplifier for your HD800 or HD800S, then look no further. The Sennheiser flagship is certainly being pushed to its full potential here.

But of course, for the balanced output you will need two CMA800Rs.

THE WHOLE STACK Once it all comes together, there are a few things that are worth noting.

Firstly, the visual statement and aesthetic of the stack is one that means business. From the first glance, it becomes immediately obvious that this is pitched squarely at the serious enthusiast or discerning buyer.

The sheer versatility of the stack is incredible. Not only is it completely self-sufficient, but each device has such an epic array of inputs and outputs. The stack integrates into the rest of my gear.

Tube preamp? No problem. Digital EQ? Sure thing. I was even able to A/B test some other preamps I had, and with perfect volume matching. The stack does a lot more than just what it says on the tin.

If you’re willing to shell out for the entire stack, which is certainly no cheap task at just north of $18,000 by my calculations, then what you will receive is an incredibly high quality, versatile setup that can faithfully power a wide range of headphones.

Make no mistake, this is high-end product. If you ever find yourself searching for an all-in-one setup with full mono balanced outputs, switchable FIR digital filters, True DSD compatibility, and a stunning finish, you’ve just found it with the Questyle Audio ‘Gold Stack’.