Questyle​

Based in China, Questyle Audio Engineering is celebrated for its skill in producing DACs and headphone amplifiers. They are especially recognized for their Current Mode Amplification (CMA) technology, which is acclaimed for removing metallic tones and considered superior to other competing technologies.

Highlighting their dedication to innovation, Questyle has garnered more than 20 global awards since 2015, such as the CES Innovation Award, iF Industrial Design Award, and VGP Lifestyle Award, to name a few.

With the launch of their newest product, the CMA 15, there is significant anticipation for a device that promises sophisticated design and quality. It remains to be seen whether it will uphold the lofty expectations established by its forerunners.

Introduction​

How did I stumble upon the CMA15? The onset of the global pandemic had me seeking a replacement for my trusted Bose QC35 headphones, which I previously considered to be among the best available. Unaware of the extensive head-fi universe until then, I began a journey of successive upgrades, immersing myself in the audio realm. After evaluating various models, I eventually settled on the Abyss 1266 PHI TC, Hifiman Susvara, and Focal Utopia. For listening to music on the move, I opted for the Empire Ears Odin and Oriolus Traillii JP.

Now, in order to build a solid foundation for my headphone setup, I have shifted my quest towards finding the perfect DAC/AMP combination. I believe that headphones account for approximately 95% of the listening experience, thus minimizing the impact of other equipment, cables, or accessories. Although these elements are important, my initial step was to identify the ideal headphones before seeking out the other components needed to complete the setup. Accommodating a wide range from the sensitive Odins to the power-hungry Susvaras is no easy task. I've tried out various devices, such as the JDS Labs Element II, RME ADI-2 DAC, Topping D90SE/A90 stack, Niimbus US4+, and Chord Hugo 2. Presently, my lineup includes the Shanling EM5, Felix Euforia MKII, and WA7 3rd generation. The CMA15 is also on my radar as I continue to refine my DAC/AMP system.

I had previously been intrigued by the CMA15, but it was not available in my area. I considered buying it online, yet the scarcity of reviews and information deterred me. Then, as if by destiny, Questyle announced a head-fi review tour. I quickly signed up and, fortunately, was chosen, leading to a fortuitous series of events.

And so, the stage is set. I aim to provide meaningful insights into the CMA15 and share my personal experiences with the device.

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Build Quality​

Let's explore the basics.

The CMA15 serves a dual function, combining a DAC and an amplifier in one unit. It's larger than setups like the Topping A90/D90 stack but smaller compared to the Niimbus US4+. It fits well on a desktop, though it takes up a significant amount of space.

The build quality is solid; the switches feel smooth and convey a sense of luxury. The entire unit is robust and meticulously crafted, with no weak or unstable parts. However, while the finish is impressive, it doesn't reach the highest industry standard. Questyle could improve this feature to match the quality of their rivals. The design is pragmatic, reflecting its engineering-driven creation where functionality takes precedence over appearance. Were aesthetics my only criterion, I might prefer the Shanling EM5 for my desktop setup rather than the CMA15.

ES9038PRO​

It's a common belief that devices with multiple functions might lack in specific areas. Yet, the DAC portion of the CMA15 defies this expectation. It utilizes the ES9038PRO chip, the latest premium chip from ESS intended for both audiophile use and professional studio settings. This places it among the elite chips on the market today, particularly for those interested in the delta-sigma approach.

Current Mode Amplification​

Talking about this subject feels a bit beyond my expertise since I lack the technical background of an engineer and don't fully grasp the complex workings involved. However, I'll rely on Questyle's explanation for better clarity:

"Central to Current Mode Amplification is the principle of using current, as opposed to voltage, for the amplification of audio signals. This contemporary method of audio amplification is distinctively superior to traditional audio amplifiers in performance. Considered the 'engine' of the audio system, Current Mode Amplification boasts an entirely discrete and sophisticated structure. This allows for an impeccable sound performance so authentic that it feels as if one is present in the original recording environment. With the utilization of Current Mode Amplification technology, even everyday headphones and speaker systems can deliver an elevated auditory experience."

Questyle owns the patent for this technology, and many of their products include the initials (CMA), marking this as a signature feature that differentiates them from competitors. I am truly excited to experience how this translates into actual sound quality.

Connectivity​

I'll keep this section brief; for an in-depth look at the connection options, please consult the product's datasheet or its official website. The device offers an extensive array of connectivity features: XLR and RCA outputs, RCA analog inputs, USB Type-B and Type-C ports, as well as optical and S/PDIF inputs. Additionally, it features Bluetooth input with LDAC codec support, a notable addition, especially since it's compatible with Apple Music.

A particular aspect I value highly is the USB Type-C input. It's surprising that many companies still haven't embraced USB Type-C, opting instead to release new products with the outdated micro-USB in 2022.

For headphones and IEMs, the device provides all the standard connections: XLR, 6.35mm, and 4.4mm jacks, reducing the necessity for various adapters, which is definitely a plus! .

Sound​

Okay, let's delve into the sound quality and performance .

First off, I want to share my approach to evaluating sound quality for clarity. As I've previously stated, I believe the choice of headphones plays a crucial role in shaping the audio experience, making up about 95% of it, more than any other equipment, cables, or accessories you might use. Of course, your viewpoint may differ, which is completely fine. Audio enjoyment is a personal journey, and we all have our individual tastes and priorities. That’s my perspective.

For my testing to be consistent, I use a sound meter to ensure the volume levels are equal across all devices, utilizing a 1KHZ sine wave and adjusting it to hit 80DB. While I usually opt for a lower volume during leisure listening, I turn it up a bit for test conditions. This approach is not as effective with IEMs, hence my evaluations in those instances lean more towards the subjective side.

I've also compiled a collection of short audio loops that include sounds from instruments like cymbals, beats, and hi-hats, which helps me compare how they are rendered on different equipment. These brief loops are beneficial for maintaining a clear memory of the sounds as I switch between devices.

In general, the CMA15 provides an exceptionally clear, detailed, and transparent sound across the frequency range. There’s no dominant or overshadowing element, which I find perfect. The device effectively fades into the background, allowing my headphones to shine.

With the Susvara, the natural resonance and accurate instrument reproduction are remarkably evident. On the other hand, the 1266 TC reveals an abundance of detail, highlighting its unique industrial sound and strong bass. The CMA15 has sufficient power to drive these headphones without any shortcomings. Using my headphones with the CMA15 was thoroughly enjoyable.





For me, the ability of a device to handle IEMs without producing any hiss is a critical criterion before considering it for purchase. I've tried various devices at different price ranges, and many have disappointed me with the hiss they produce when used with my IEMs. A device that can operate without this hiss demonstrates superior performance and engineering quality in my eyes.

The CMA15 stands out in this respect, as it operates without any hiss with my IEMs, which is something I highly appreciate. Using the CMA15 with the Traillii and Odin was an absolute delight. The Odin revealed intricate details, especially in its superb bass texture, while the Traillii offered speed that could match a Formula 1 car, with electrostatic treble that sparkled exactly to my liking.

Conclusion​

Overall, I was very impressed with the CMA15. It comes fully equipped with essential inputs, including a contemporary USB type-C port and Bluetooth compatibility with LDAC codec. For enthusiasts, it provides all the necessary headphone outputs: XLR, 6.35mm, and 4.4mm. The superior audio quality is unmistakably due to its incorporation of the latest ESS flagship chips, resulting in a sound that is richly detailed, clear against a quiet backdrop, and authentically reproduced, just as one would expect. Importantly, the device maintains a neutral sound profile, allowing the inherent characteristics of your headphones to come through while also delivering sufficient power.

My only criticism is related to its design, which feels somewhat outdated compared to my other more modern-looking devices. However, this point is highly subjective since aesthetic tastes differ greatly, and this comment could be applicable to other devices as well, such as the Niimbus US4+. Aside from this minor aspect, in terms of sound quality and connectivity, it meets all my expectations for such a product, and I wholeheartedly recommend it.