This review piece is published by EARPHONE AESTHETICS, a Chinese media platform specializing in headphones, and is written by an author known as DC.
"In recent years, the size of high-end portable players has noticeably increased, a trend that's easily explained. Solutions like Ultraportable DACs, designed to work seamlessly with mobile phones, are not only becoming simpler to develop but also significantly more powerful. This evolution has put pressure on manufacturers of traditional portable players, particularly those in the high-end market. They find it challenging to match the portability and user-friendliness of Ultraportable DACs. To stay competitive and maintain their market share in an industry that values differentiation, these manufacturers are focusing more on enhancing sound quality. As a result, mid to high-end portable players have become bulkier and heavier, a reluctant but necessary adjustment.
However, one should acknowledge that even professionals in the audio industry, like myself, are unwilling to carry an additional "big brick" while on the move. Yet, the majority of Ultraportable DACs available today fall short of meeting our stringent criteria for sound quality, not to mention a charging port. So, what's the ideal solution? Bluetooth DAC earbuds could be the key. Those familiar with my reviews might remember the QULOOS MUB1, an exceptional Bluetooth DAC earbud we highlighted last year, which I regarded as the top portable front-end device of the year. Today, I'm excited to talk about the Kuangshi CMA18 Portable, another premium solution for portable music that is sure to supplant many mid to low-end players and comes highly recommended.
Firstly, let's delve into the positioning of the CMA18P. Before the Beijing exhibition last year, Questyle announced the release of two flagship products, marking a significant moment. Among those products, there was an eagerly awaited new desktop flagship, the CMA18 Master. This is an all-in-one DAC amp. The other item I would like to discuss was the CMA18 Portable. The shared CMA18 model in their names underscores their premier status in their respective categories. With a price tag of RMB 4490, the CMA18P is positioned at the high end, especially for a Bluetooth decoding amplifier, which heightens my anticipation for its performance before even experiencing it firsthand. After all, it's about offering performance that lives up to its value.
Questyle is a brand that pays great attention to design and packaging, which are well known for their simplicity yet elegance. Thus, the CMA18P's packaging features black paper boxes and silver "ID photos", with a drawer-style compartment for cable storage and clear button instructions inside the box. These elements reflect the brand's consistent approach to precision and modesty. However, Questyle sets itself apart from other brands, mainly focusing on industrial design by embracing simplicity without sacrificing aesthetics. On the box, there is a quote of the 18th-century German composer – Christoph Gluck, "I Firmly Believe That Simplicity And Authenticity Are The Principles Of Beauty In All Works Of Art." In doing so, the company accentuates the artistic essence of its design philosophy.
Questyle’s clients have particularly appreciated transparent shells that have also challenged internal design in recent years, e.g. the M15, CMA400, CMA12, CMA18M as well as CMA18P machines introduced in this article. I personally like this kind of design that is full of industrial aesthetics. It also demonstrates the manufacturer's confidence in the internal circuit design.
In terms of dimensions, the size of 7cm * 11cm * 15cm is quite petite. The weight of over 150 grams also meets the criteria. When it is used with a wired connection to hold the phone in hand or with Bluetooth connectivity tucked in a pocket, users will hardly feel any weight. The transparent panel on the front is made of Corning glass, but there is still a risk of scratches with prolonged use. It would be even more perfect if the manufacturer could provide a protective cover.
Despite its compact size, the device features a big array of input and output interfaces. Beyond Bluetooth and USB, the CMA18P also supports optical and line inputs. On the output side, it is equipped with the most common 3.5mm single-ended and 4.4mm balanced analog output jacks. In most cases, we would primarily use Bluetooth and USB connections with this device. The Bluetooth optimization is impressively high, showing almost no significant difference compared to USB mode. Its strongest points are the design, resolution, and both high and low frequency extension. The delicacy of the sound is also at the same level as with USB. Users purchasing it primarily for using it with Bluetooth headphones will definitely appreciate this.
Once you become familiar with the operational logic of the CMA18P, the user experience will become very smooth and enjoyable. Since the device does not feature a small screen, operations are entirely conducted via LED indicators and function switch buttons. After getting used to it, there's absolutely no need to worry. The interaction logic between the function buttons and the signal lights is very clear. Clients only need to press the function button briefly to switch between various input modes such as USB, coaxial, and Bluetooth. Moreover, while adjusting the toggle one can switch the gain. The overall operation experience is very user-friendly.
Seeing the CMA18P priced "as high as" over 4,000 RMB but still equipped with the AK4493 chip, might again unsettle some "chip theory enthusiasts." However, it's worth reiterating a few points. First, the AK4493 is widely recognized for its solid performance and distinctive sound signature; second, for portable devices, the key issue is not which chip is used, but whether the potential of the chip is fully realized. In the early years, when Questyle launched devices like the QP2R and QPM, many competitors had already moved on to flagship chips like the AK4497 and AK4499. However, Questyle continued to use the AK4490 and achieved sound performance that was in no way inferior to those of its competitors, teaching a lesson to those who only focus on technical specs. Similarly, the CMA18P's ability to fully unleash the potential of its DAC chip relies on meticulous attention to the peripheral circuitry.
The CMA18P, despite its compact and portable form, makes no compromises on internal components. Its confidence stems from Questyle's proprietary technology, the four-group current mode PCT patent SiP chip. The fundamental principle of this technology is to use transistors as amplifying devices in a fully discrete architecture for the amplification section. It maintains both input and output in voltage mode, thereby keeping the operational state constantly in pure Class A. This circuit structure fundamentally differs from traditional voltage mode amplification, with transistor inter-stage capacitors operating at very low impedance nodes. As a result, it eliminates transient intermodulation distortion as well as easily achieves higher bandwidth and lower distortion for superior performance. This technological approach diverges significantly from many similar products that use operational amplifier chips for amplification. It bypasses the limitations of op-amp chips, demonstrating stronger power reserves and control.
If I were to describe the sound style of the CMA18P, I would likely use the terms "refined" and "graceful." The former emphasizes beauty on a smaller scale, whereas the latter conveys a sense of grandeur and dignity. They might seem contradictory at first glance. However, Questyle has successfully integrated these seemingly opposing styles into one device, creating an unexpectedly harmonious product. When it comes to the refined vocal performance of the CMA18P, it delicately and gently reproduces the vocals in pop music. This tuning style is highly suitable for music and emphasizes an elegant refinement. In terms of details, the CMA18P employs a relatively warm low frequency to enhance the warmth of the vocals, with both the release and dynamics handled very naturally, contributing to an outstanding sense of atmosphere. The moderate distance of the vocals also makes them sound very comfortable to the listener.
Those familiar with Questyle's previous products might learn more about the QPM by reading this. Indeed, the tuning style of the CMA18P is very similar to that of the QPM, both featuring a soft and elegant style. However, in terms of vocal performance, the CMA18P is more delicate than the QPM. Moreover, Questyle has applied a "feathering" technique similar to that used in PS (Photoshop) technology, softening the edges of the vocals to make the listening experience more pleasant and enduring. Such an aesthetic style is well-suited to showcasing the gentle side of music, conveying a sense of ease and composure without overly emphasizing a sense of quality.
The CMA18P offers high-quality sound while being exceptionally pleasant to listen to for extended periods. It expresses sound quality in a manner that's more easily accepted by listeners, enhancing its musicality. Listening to music with the CMA18P is a thoroughly enjoyable experience, allowing one to let go of the pointless pursuit of details. Even after prolonged listening, it doesn't lead to fatigue. If you pay at least slight attention to the detail, you'll certainly notice that every detail is exactly where it should be, perfectly balancing sound quality and listening comfort.
While the CMA18P processes vocals in a very gentle manner, its sound is far from lacking in strength. When listening to instrumental music, the CMA18P, with its excellent sense of space, superbly showcases instruments like drums and horns that are typically positioned in the back, fully conveying the spirited emotions and expressiveness of these instruments. This broadens our perspective on music appreciation, as if stepping out from a small corner to see the "whole picture" of the music. However, the CMA18P does focus solely on a detailed and majestic reproduction of instruments' grandeur. Instead, it uses a slightly warm timbre to soften that "solemnity," making the listening experience more pleasing to the ear. If I were to use one word to describe the instrumental style of the CMA18P, it would be "graceful," as previously mentioned—gentle, demure, yet with a sense of presence.
Upon refocusing on the details, one discovers that the CMA18P intricately and delicately renders the nuances of each instrument's overtones. This results in a paradoxical yet harmonious experience when listening to large-scale vocal compositions. It's comparable to observing a grand and magnificent palace, where every detail of the carved balustrades and jade constructions is exquisitely crafted. This is precisely why I describe the sound style of the CMA18P as both "refined" and "graceful."
This type of sound style naturally goes well with various equipment, and at least many of the devices I have tested sound quite good with it. Taking the FAudio Spring as an example, this dynamic driver headphone is also an excellent product in the 5000 RMB price range. Although it has a mid-low frequency orientation, it surprisingly offers a transparent performance in string instruments, with a rich timbre, solid and thick midrange, making it versatile across different music genres and styles, from pop to instrumental. If there's room for further optimization, it would be its pairing with equipment that focuses on analytical capabilities, which may make some female vocals and string music slightly too sharp. However, it can enrich the listening experience as a form of "enticement." However, when paired with the CMA18P, this barely perceptible sharpness is smoothed out as much as possible. The gentle luster of the CMA18P further refines the already pleasant listening style of the FAudio Spring, adding additional moisture to pop vocals and instrumental music.
The warm, pleasant, and high-quality sound of Temperament Bell-Black has greatly appealed to me. When paired with the CMA18P, the rich sound quality of both create a synergy that is more than the sum of their parts. This is particularly true for pop vocals, where the midrange is warm, delicate, and slightly pronounced, perfectly conveying emotions. The bass has a moderate sense of power with a rich atmospheric feel, while the treble transitions smoothly, almost without any harshness. The harmonic details are abundant but never intrusive to the listening experience. I really enjoy such a comfortable performance, especially when I want to listen to music before falling asleep.
The CMA18P and Questyle's own NHB15 make for a very impressive "suit pairing." Since both devices lean towards a moist sound, their combination produces a warmth that resonates at the core. However, unlike many warm sounds that can become somewhat "cloying," the NHB15's hint of brightness blends well with the CMA18P's softness and refined style, resulting in a vivid and clear presentation. The sound they produce together is particularly suited for listening to male pop vocals, offering both moisture and depth.
By this point, everyone has likely gained a thorough understanding of the CMA18 Portable. Questyle has conducted in-depth research into its sound quality and elevated it through their proprietary acoustic circuit technology. Coupled with exquisite design and craftsmanship, they have produced the CMA18P, a device of remarkable completion. Featuring dual-mode decoding through both Bluetooth and USB, the CMA18P indeed strikes a near-perfect balance between sound quality and ease of use in a portable format at this stage. With the CMA18P setting such a trend, it's expected that more manufacturers will eagerly follow suit in the future."
"In recent years, the size of high-end portable players has noticeably increased, a trend that's easily explained. Solutions like Ultraportable DACs, designed to work seamlessly with mobile phones, are not only becoming simpler to develop but also significantly more powerful. This evolution has put pressure on manufacturers of traditional portable players, particularly those in the high-end market. They find it challenging to match the portability and user-friendliness of Ultraportable DACs. To stay competitive and maintain their market share in an industry that values differentiation, these manufacturers are focusing more on enhancing sound quality. As a result, mid to high-end portable players have become bulkier and heavier, a reluctant but necessary adjustment.
However, one should acknowledge that even professionals in the audio industry, like myself, are unwilling to carry an additional "big brick" while on the move. Yet, the majority of Ultraportable DACs available today fall short of meeting our stringent criteria for sound quality, not to mention a charging port. So, what's the ideal solution? Bluetooth DAC earbuds could be the key. Those familiar with my reviews might remember the QULOOS MUB1, an exceptional Bluetooth DAC earbud we highlighted last year, which I regarded as the top portable front-end device of the year. Today, I'm excited to talk about the Kuangshi CMA18 Portable, another premium solution for portable music that is sure to supplant many mid to low-end players and comes highly recommended.
Firstly, let's delve into the positioning of the CMA18P. Before the Beijing exhibition last year, Questyle announced the release of two flagship products, marking a significant moment. Among those products, there was an eagerly awaited new desktop flagship, the CMA18 Master. This is an all-in-one DAC amp. The other item I would like to discuss was the CMA18 Portable. The shared CMA18 model in their names underscores their premier status in their respective categories. With a price tag of RMB 4490, the CMA18P is positioned at the high end, especially for a Bluetooth decoding amplifier, which heightens my anticipation for its performance before even experiencing it firsthand. After all, it's about offering performance that lives up to its value.
Questyle is a brand that pays great attention to design and packaging, which are well known for their simplicity yet elegance. Thus, the CMA18P's packaging features black paper boxes and silver "ID photos", with a drawer-style compartment for cable storage and clear button instructions inside the box. These elements reflect the brand's consistent approach to precision and modesty. However, Questyle sets itself apart from other brands, mainly focusing on industrial design by embracing simplicity without sacrificing aesthetics. On the box, there is a quote of the 18th-century German composer – Christoph Gluck, "I Firmly Believe That Simplicity And Authenticity Are The Principles Of Beauty In All Works Of Art." In doing so, the company accentuates the artistic essence of its design philosophy.
Questyle’s clients have particularly appreciated transparent shells that have also challenged internal design in recent years, e.g. the M15, CMA400, CMA12, CMA18M as well as CMA18P machines introduced in this article. I personally like this kind of design that is full of industrial aesthetics. It also demonstrates the manufacturer's confidence in the internal circuit design.
In terms of dimensions, the size of 7cm * 11cm * 15cm is quite petite. The weight of over 150 grams also meets the criteria. When it is used with a wired connection to hold the phone in hand or with Bluetooth connectivity tucked in a pocket, users will hardly feel any weight. The transparent panel on the front is made of Corning glass, but there is still a risk of scratches with prolonged use. It would be even more perfect if the manufacturer could provide a protective cover.
Despite its compact size, the device features a big array of input and output interfaces. Beyond Bluetooth and USB, the CMA18P also supports optical and line inputs. On the output side, it is equipped with the most common 3.5mm single-ended and 4.4mm balanced analog output jacks. In most cases, we would primarily use Bluetooth and USB connections with this device. The Bluetooth optimization is impressively high, showing almost no significant difference compared to USB mode. Its strongest points are the design, resolution, and both high and low frequency extension. The delicacy of the sound is also at the same level as with USB. Users purchasing it primarily for using it with Bluetooth headphones will definitely appreciate this.
Once you become familiar with the operational logic of the CMA18P, the user experience will become very smooth and enjoyable. Since the device does not feature a small screen, operations are entirely conducted via LED indicators and function switch buttons. After getting used to it, there's absolutely no need to worry. The interaction logic between the function buttons and the signal lights is very clear. Clients only need to press the function button briefly to switch between various input modes such as USB, coaxial, and Bluetooth. Moreover, while adjusting the toggle one can switch the gain. The overall operation experience is very user-friendly.
Seeing the CMA18P priced "as high as" over 4,000 RMB but still equipped with the AK4493 chip, might again unsettle some "chip theory enthusiasts." However, it's worth reiterating a few points. First, the AK4493 is widely recognized for its solid performance and distinctive sound signature; second, for portable devices, the key issue is not which chip is used, but whether the potential of the chip is fully realized. In the early years, when Questyle launched devices like the QP2R and QPM, many competitors had already moved on to flagship chips like the AK4497 and AK4499. However, Questyle continued to use the AK4490 and achieved sound performance that was in no way inferior to those of its competitors, teaching a lesson to those who only focus on technical specs. Similarly, the CMA18P's ability to fully unleash the potential of its DAC chip relies on meticulous attention to the peripheral circuitry.
The CMA18P, despite its compact and portable form, makes no compromises on internal components. Its confidence stems from Questyle's proprietary technology, the four-group current mode PCT patent SiP chip. The fundamental principle of this technology is to use transistors as amplifying devices in a fully discrete architecture for the amplification section. It maintains both input and output in voltage mode, thereby keeping the operational state constantly in pure Class A. This circuit structure fundamentally differs from traditional voltage mode amplification, with transistor inter-stage capacitors operating at very low impedance nodes. As a result, it eliminates transient intermodulation distortion as well as easily achieves higher bandwidth and lower distortion for superior performance. This technological approach diverges significantly from many similar products that use operational amplifier chips for amplification. It bypasses the limitations of op-amp chips, demonstrating stronger power reserves and control.
If I were to describe the sound style of the CMA18P, I would likely use the terms "refined" and "graceful." The former emphasizes beauty on a smaller scale, whereas the latter conveys a sense of grandeur and dignity. They might seem contradictory at first glance. However, Questyle has successfully integrated these seemingly opposing styles into one device, creating an unexpectedly harmonious product. When it comes to the refined vocal performance of the CMA18P, it delicately and gently reproduces the vocals in pop music. This tuning style is highly suitable for music and emphasizes an elegant refinement. In terms of details, the CMA18P employs a relatively warm low frequency to enhance the warmth of the vocals, with both the release and dynamics handled very naturally, contributing to an outstanding sense of atmosphere. The moderate distance of the vocals also makes them sound very comfortable to the listener.
Those familiar with Questyle's previous products might learn more about the QPM by reading this. Indeed, the tuning style of the CMA18P is very similar to that of the QPM, both featuring a soft and elegant style. However, in terms of vocal performance, the CMA18P is more delicate than the QPM. Moreover, Questyle has applied a "feathering" technique similar to that used in PS (Photoshop) technology, softening the edges of the vocals to make the listening experience more pleasant and enduring. Such an aesthetic style is well-suited to showcasing the gentle side of music, conveying a sense of ease and composure without overly emphasizing a sense of quality.
The CMA18P offers high-quality sound while being exceptionally pleasant to listen to for extended periods. It expresses sound quality in a manner that's more easily accepted by listeners, enhancing its musicality. Listening to music with the CMA18P is a thoroughly enjoyable experience, allowing one to let go of the pointless pursuit of details. Even after prolonged listening, it doesn't lead to fatigue. If you pay at least slight attention to the detail, you'll certainly notice that every detail is exactly where it should be, perfectly balancing sound quality and listening comfort.
While the CMA18P processes vocals in a very gentle manner, its sound is far from lacking in strength. When listening to instrumental music, the CMA18P, with its excellent sense of space, superbly showcases instruments like drums and horns that are typically positioned in the back, fully conveying the spirited emotions and expressiveness of these instruments. This broadens our perspective on music appreciation, as if stepping out from a small corner to see the "whole picture" of the music. However, the CMA18P does focus solely on a detailed and majestic reproduction of instruments' grandeur. Instead, it uses a slightly warm timbre to soften that "solemnity," making the listening experience more pleasing to the ear. If I were to use one word to describe the instrumental style of the CMA18P, it would be "graceful," as previously mentioned—gentle, demure, yet with a sense of presence.
Upon refocusing on the details, one discovers that the CMA18P intricately and delicately renders the nuances of each instrument's overtones. This results in a paradoxical yet harmonious experience when listening to large-scale vocal compositions. It's comparable to observing a grand and magnificent palace, where every detail of the carved balustrades and jade constructions is exquisitely crafted. This is precisely why I describe the sound style of the CMA18P as both "refined" and "graceful."
This type of sound style naturally goes well with various equipment, and at least many of the devices I have tested sound quite good with it. Taking the FAudio Spring as an example, this dynamic driver headphone is also an excellent product in the 5000 RMB price range. Although it has a mid-low frequency orientation, it surprisingly offers a transparent performance in string instruments, with a rich timbre, solid and thick midrange, making it versatile across different music genres and styles, from pop to instrumental. If there's room for further optimization, it would be its pairing with equipment that focuses on analytical capabilities, which may make some female vocals and string music slightly too sharp. However, it can enrich the listening experience as a form of "enticement." However, when paired with the CMA18P, this barely perceptible sharpness is smoothed out as much as possible. The gentle luster of the CMA18P further refines the already pleasant listening style of the FAudio Spring, adding additional moisture to pop vocals and instrumental music.
The warm, pleasant, and high-quality sound of Temperament Bell-Black has greatly appealed to me. When paired with the CMA18P, the rich sound quality of both create a synergy that is more than the sum of their parts. This is particularly true for pop vocals, where the midrange is warm, delicate, and slightly pronounced, perfectly conveying emotions. The bass has a moderate sense of power with a rich atmospheric feel, while the treble transitions smoothly, almost without any harshness. The harmonic details are abundant but never intrusive to the listening experience. I really enjoy such a comfortable performance, especially when I want to listen to music before falling asleep.
The CMA18P and Questyle's own NHB15 make for a very impressive "suit pairing." Since both devices lean towards a moist sound, their combination produces a warmth that resonates at the core. However, unlike many warm sounds that can become somewhat "cloying," the NHB15's hint of brightness blends well with the CMA18P's softness and refined style, resulting in a vivid and clear presentation. The sound they produce together is particularly suited for listening to male pop vocals, offering both moisture and depth.
By this point, everyone has likely gained a thorough understanding of the CMA18 Portable. Questyle has conducted in-depth research into its sound quality and elevated it through their proprietary acoustic circuit technology. Coupled with exquisite design and craftsmanship, they have produced the CMA18P, a device of remarkable completion. Featuring dual-mode decoding through both Bluetooth and USB, the CMA18P indeed strikes a near-perfect balance between sound quality and ease of use in a portable format at this stage. With the CMA18P setting such a trend, it's expected that more manufacturers will eagerly follow suit in the future."
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