Questyle CMA18 Portable / CMA18P

Preamble​

I purchased the Questyle CMA18 Portable (CMA18) at my own cost and Questyle have had no input on the below review. The rating is a mix of both Sound and Quality of Life and Value. For the CMA18, Sound gets 4.5 stars and Quality of Life gets 3.5 stars leading to the resulting overall rating.

I note that the above rating is based on the testing of the CMA18 with the following IEMs:

• BLON BL-03 (Single DD budget);
• Campfire Audio Supermoon (Single planar driver kilobuck);
• Letshuoer S12 Pro (Single planar budget-ish)
• Unique Melody MEST MK2 (Quad-brid kilobuck-ish); and
• Unique Melody Multiverse Mentor (BA and Bone conduction driver hybrid TOTL),

meaning I had no testing with over-ear headphones.

It is rather ironic that in the quest for a better sounding portable setup that many end up with something that is less and less portable. It starts with a small USB dongle that evolves to a DAP which evolves to an even bigger DAP that is strapped to a separate discrete amplifier. Soon you will be carrying a car battery in your backpack to hook up to 4 amps daisy chained together. Whilst many may never end up at this point, it is important to look at what you get along this journey and whether sound quality is every worth the trade-off in convenience. Today’s review concerns a power-bank sized audio device, the CMA18 Portable from Questyle that promises a step-up from your tiny dongles but the question is, at what cost?

The Factual Stuff​

The CMA18 is a portable audio device featuring a DAC, amplifier and ADC in one rather sleek looking package.

Featuring an aluminium frame with two gorilla glass panels, there is a glimpse into the internal workings of the CMA18 much like my Gameboy Colour of yesteryear. Within the CMA18 is a single AK4493 DAC, 4x “PCT-class current-mode SiP” chips and a 4300 mAh battery.

The left side is flanked with a litany of buttons with power, input select, volume up and down, a hold slider and a gain slider.

In terms of input, there is a USB-C combo power and input at the bottom along with you choice of optical/TOSlink and Bluetooth with support for aptX and LDAC. In terms of output, you have a choice of either 3.5mm and 4.4mm. Out of the balanced output, you will be getting 1W through 32 ohms.

Within the rather cool box you get the CMA18, a charging cable, a USB-C to USB-C OTG cable, a USB-C to Lightning OTG cable and some literature.

The Opinion Stuff​

Sound​

Whilst a source doesn't necessarily have a sound signature (or one at all if /r/headphones is to believed) that is universally applicable to all IEMs, there are a number of traits that I can discern that is generally applicable to the IEMs listed above.

Bass​

The CMA18 seems to impart a degree of low-end oomph that is quite satisfying to listen to. The sub-bass frequencies, especially on the single DD BL-03 got a greater injection of physicality with the CMA18 providing something that was very robust in its power. There is a degree of overdoing it with already bassy IEMs but on the whole, this provision of low-end power is something that I feel is wholly enjoyable. This is not the old crank the left-side of your graphic equalizer up in terms of bass boost, it remains tight, controlled and not overly boomy to the ear. Mid-bass frequencies also seem to get a greater level of presence and punch with songs such as “Dreams” by Fleetwood Mac which doesn’t seek to wow you with low-end production (I mean it was released in 1977) seems to get a great sense of rhythm and pace with the added mid-bass presence on the CMA18. Overall, there is a good sense of power and depth here that adds a great sense of fun factor to your IEMs.

Mids​

The midrange on the CMA18 seems quite well balanced with neither male or female vocalists stealing the show from the other. There is a slight forward nature to the mid-range as vocalists seem to sit slightly forward in the stage. The lower-mids sound quite nice to listen to with the aforementioned bass boost injecting a sense of weightiness in this presence that enhances my emotional engagement with music. This is a rather welcome signature as I feel that a lot of audio devices, not just sources, seek to be over clinical at times. Upper-mids sound sweet and natural with songs like “Billie Bossa Nova” by Billie Eilish presenting in a very natural and slightly forward manner, as if Billie was whispering into your ear.

Instrumental-heavy music such as orchestral pieces like “One-Winged Angel” by Nobuo Uematsu sound engaging and quite well timbred. The details of the strings sound coherent and well presented in the stage.

Overall, there is not much to hate here with a well-natured approach to the mids that seeks to enhance musicality and technical performance in a balanced way.

Treble​

Moving to the treble, the CMA18 also does a good job at rendering the upper-regions of the FR curve in a well-meaning manner, remaining quite enjoyable to the ear. There is seemingly, a slight smoothing out going on here with rather sharp IEMs such as the S12 Pro, quite often fatiguing at times managing to be quite listenable over longer-periods of time. I do not feel that this region loses out in terms of quantity but it seems to get relaxed a little and presents in a manner that is more laid-back. Some trebleheads may dislike the spine-tingling rendition of percussion and I found myself wanting a little more from songs like “Reckoner” by Radiohead but overall, I cannot fault the CMA18 here.

Whilst not the forefront of the CMA18, treble doesn’t seem to lose out its detail and its extension, with a greater sense of dynamic range compared to the Shanling M6U but its engagement level with me had dropped significantly.

Overall, the CMA18’s treble region is well-meaning and hard-to-hate for me. I don’t mind it but it’s definitely not the standout here.

Technicalities​

The technical performance of the CMA18 is likely its most impressive element. The music sounds dynamic, wide and just big in nearly every aspect. Detail retrieval and resolution is a definite bonus with the CMA18 when compared to lesser sources. The single AKM chip and the rather impressive amplifier in the CMA are working overtime to produce some very well defined notes that don’t seek to overwhelm you with detail but rather, balances musicality at the same time.

Soundstage on the CMA18 is seemingly expanded from the likes of the M6U and there is a greater sense of stage width, depth and height that comes to life on well-produced tracks in my library.

Imaging on the CMA18 is also excellent. When paired with a technically proficient IEM, there is a clear separation of notes and a great level of identifying certain lines of instrumentalization and vocalisation in busily produced tracks such as “Fine” by Taeyeon.

Where the CMA18 suffers however, is its noise floor. Noiser amplifiers fail to produce a ‘darker’ background which detracts from a sense of dynamism and just overall enjoyment of more sparsely produced tracks. “No Time to Die” by Billie Eilish has some sections with limited instruments and yet you hear a faint hiss throughout. This is something that I have been conditioned to notice after owning an Andromeda for a period of time and for some, this is a non-issue. However, it is something to note with the CMA.

Quality of Life & Value​

The CMA18 is priced at approximately $700 USD and for that you get a very versatile source. It is a DAC, amp, ADC and wireless Bluetooth player in a rather pocketable package. Based on versatility alone and its sound quality, I feel that the CMA18 represents great value. The ADC is a bit of an odd inclusion as I don't really have any use for it but I suppose measureabators and music-makers will enjoy it. I would have preferred the potential to use the CMA18 as a pure amp utilising the line-out of a DAP or external DAC in the same vein as popular solutions such as the iBasso PB5 Osprey, Brise Audio Tsuranagi or the Mass Kobo MK475. This is not to say you can pass through some analogue audio but it will be converted back to digital for processing by the CMA18's DAC.

There is perhaps a consideration for what IEM you seek to pair with the CMA18 as well. In my testing, the planar drivers and the dynamic driver IEMs that I had on hand seemed to work well with the CMA18 with an increased degree of shift in sound compared to my multi-BA sets. This may just be with my lineup of IEMs but is something that I noted with my Mentor seemingly sounding rather pedestrian with the CMA18. Some input from fellow audiophiles have stated that theoretically, a current-focused amplifier stage (such as that in the CMA18) will enliven dynamic drivers more so than balanced armatures. Snake oil? Perhaps. Coinciding with my anecdotes? Yes. Now taken as a truth for me? Sure.

Outside of the spec sheet, there are some quality of life issues that I would be remiss not to note. The CMA18, whilst quite cool looking with its industrial design, is glass and as such, is unlikely to handle the bumps and falls of other devices. It is also quite slippery on services and no one wants their device to be flung across the room when they forget to unplug it. The case that I have received with my CMA18 which is from a brand named Jutem (which I understand to be a China-centric brand) is a very necessary purchase.

The litany of buttons on the side is a rather necessary evil but they are quite rattly and loud to use. Furthermore, the volume steps that you get with the CMA18 is quite limited. It’s not hard to go from “I can’t hear anything” to “I can’t hear anything, anymore, ever”.

Bluetooth works a treat if you’re into that thing and I quite enjoyed having it in the pocket whilst playing around on my phone or just walking around the house whilst whatever device was doing playback remaining stationary. Range is not hugely impressive but it is completely fine for my rather limited adventures. Do not expect to have several double-brick walls between your CMA18 and your PC is what I am getting at.

Battery life was decent in my very unscientific testing. No run-time measurements were taken but through a variety of listening and input sources throughout a single charge, it didn't drop dead in a single day. I found myself reaching for a charger two or so times a week with an averaging listening time of 2-3 hours a day so I don't believe it hits its stated run time of about 10 hours but hey, what does nowadays?

The CMA18 also has a tendency to get a little toasty over longer listening sessions. Residing in my jacket pocket on a commute, it go noticeably warm over time and whilst it never got to the point of being nipple burning, this is something to note for more sensitive listeners out there.

The biggest L that the CMA18 takes is in its noise-floor. It is simply just not enjoyable to have a lapse in sound in a brief refrain of a song and be greeted with SSSSSSSS. This is not to say that it is deficient to the point of breaking the CMA18 but it is merely a disappointment that I cannot unhear. With some manufacturer-stated measurements (which is always to be taken with a grain of salt) and some bad math, my calculation of the noise floor is in the region of 5.66 microvolts, which is not exactly world-beating for portable gear. For comparisons sake, my calculations for the Chord Mojo 2 yields around 5 microvolts and for the Shanling M6U, 2.7 microvolts.

On the balance of things, the CMA18 presents good quality sound with a neutral + bass-boost sound signature that aligns with its portable use. Fun on the go seems to be the theme here and it sure is fun.

Comparisons​

Shanling M6 Ultra (M6U)​

The M6U is a more expensive all-in-one device that presents with a more v-shaped signature and a significant injection of warmth in the low-end. The M6U seems more musically inclined at the cost of technical performance with a smaller stage, more fuzzy imaging / detail retrieval and just overall lower resolution. The sub-bass physicality on the CMA18 is greater and the mid-bass tightness is better. The M6U has a seemingly more bloaty low-end that bleeds slightly into the lower-mids and whilst this may be enjoyable for its enhanced note-weight, it is also more woolly sounding overall. Mids feel more clear and crisper on the CMA18 with strings and wind instruments seemingly floating out to you in a clarity that the M6U cannot match. The treble is more forward on the M6U that seeks to enhance a sense of detail and it does well to balance out the warmth. The CMA18 is smoother in this region and seems to extend further.

However, the M6U does also have all the features of the CMA18 (outside of being an ADC) with the addition of a screen and a fully fledged Android OS to allow you to stream and otherwise play with apps.

The CMA18 is an upgrade in sound quality outside of tonal considerations over the M6U and for that, I applaud the CMA18 for being better than my daily driver.

Chord Mojo 2 (from memory and notes)​

I let go of my Mojo 2 but the sheer number of hours of listening I conducted on that device leads me to believe that I can make some statements in this comparison section. The Mojo2 and the CMA18 are quite similar in many aspects, as they seek to provide a rather neutral sound signature with a low-end boost that is subtle and enjoyable. Both devices are technically impressive with an etched rendition of notes that seeks to heighten a level of detail retrieval that is not found on many lower-end devices. Where they deviate is that the Mojo2 has the benefit of a litany of rather excellent DSP features including cross-feed. Both trade blows in terms of technical performance and I would state that the CMA18 is a close match with the Mojo2 with the benefit of a much more versatile use-case. Both also share similarly poor noise floors with both producing a water-fall like hiss with more sparsely produced songs and more sensitive IEMs.

Overall, I’d go with the Mojo2 only if you could live with the lack of versatility due to the DSP features but the amplification on the CMA18 seems to add more oomph to music and runs well with more power-hungry sources.

Conclusion​

The CMA18 is the best oversized dongle that I have ever used. It is versatile, cool to look at and sounds excellent. Where it loses with me is that I simply don’t want to use it over an all-in-one solution such as a DAP and the noise floor.

The latter portion is particularly disappointing with more sensitive gear but if you have a lineup of Singaporean IEMs (notorious for being power hungry) and headphones then I do not feel that you would be missing out on much.

I characterise the CMA18 as a modernised Mojo2 without the oddities of Chord. I believe it represents good value and is let down only by its rather noisy amp and its questionable design choices. If those caveats are worth living with for a very useful and nice sounding device, then I can heartily recommend the CMA18 as your next step beyond a dongle.

Questyle Audio is dedicated to the research of high-tech lossless audio systems with perfect sound aesthetics and convenient listening experience, and provide the corresponding products, system solutions or key components according to customer requirements.
They are famous for their Current Mode Amplification topology that uses current, instead of voltage, to amplify audio signals.



Questyle CMA18

Questyle Audio is a high-end brand with many successful products like the desktop DAC/amps CMA15 & CMA18, and the portable USB DAC, the M15i. The newly released CMA18 Portable is designed to bridge that gap by achieving performance comparable to top-tier desktop setups within a portable size.

Technical stuff

The latest XMOS XU316 USB receiver is combined with the AK4493 DAC chip that supports D/A conversion up to 768kHz/32bit and DSD512. The Questyle CMA18 Portable incorporates four sets of the patented PCT-class current-mode SiP modules, each with a peak power of up to 5W and peak current of 2A. The two gain settings, coupled with high-energy current-mode amplifier technology, ensure powerful and flexible performance.

The CMA18 Portable is MFi certified, joining the mobile true-lossless era with Apple and is compatible with USB-A, USB-C, and Lightning interfaces, available for all smartphones and PCs. It supports Linux, iOS, macOS, HarmonyOS, Android and Windows with input sampling rates up to 768kHz/32bit PCM and native DSD512.



Bluetooth

The Bluetooth mode of the CMA18 Portable supports both aptX HD and LDAC, high resolution codecs, ensuring optimal wireless sound quality with a stable wireless connection. Pairing is done easily and fast after you select the Bluetooth input option by long pressing the source button. The connection is stable without dropouts and the performance is as good as the LDAC codec permits. USB decoding is definitely better but the wireless audio is still very competitive and handy when you can't utilize a cable.

Recording ADC Function

The Questyle CMA18 Portable supports the unique analog input recording function through its two stereo line-in inputs (3.5mm AUX IN and 4.4mm BAL IN). They can be connected to any audio equipment that has line-out analog outputs, including turntable systems, pre-amps, mixing consoles, and more. Once connected, the CMA18 Portable is capable of functioning as an external, lossless, high-performance analog-to-digital (ADC) recording device for either of these inputs. It also allows the user to simultaneously monitor the input during the recording process via the 3.5mm or 4.4mm outputs. Please note that this is a monitoring function and not a true analog amplifier. What you hear through your headphones is the audio signal after the ADC conversion.



How to record

When the CMA18 Portable is set to either AUX IN or BAL IN mode and connected via USB to a host device (any phone, tablet, or computer, etc that supports recording over USB), both the USB connection and REC indicator lights will appear, signaling that the recording function is enabled. The procedure is simple and there are no special requirements for recording software as long as it supports recording via external USB sound card/audio interface.

Non audio stuff

The CMA18 Portable has a rectangularly shaped chassis with beautifully rounded corners and smooth edges. The device measures 10.5 x 6.6 x 1.3cm and weighs 160g so it is slim, compact and pocket friendly while it gets easily operated with one hand. This is not a dongle so you can't have it hanging out from your phone but you can place it under the back of the phone or leave it on a desk.

The chassis is made from sandblasted aviation-grade aluminum with silver high-gloss buttons and side panels. The custom corning glass at the front face allows a view to the internal board and the amber-colored notification LEDs. It also features a gradient dot pattern and an extra RF signal suppressing coating. The back is also reinforced with corning glass that nicely highlights the Questyle logos.

The CMA18 Portable has a stylish and unique design that successfully combines luxury with minimalistic simplicity. However, the glass back can get slippery on certain surfaces and the lack of a protective case requires careful handling in order to avoid possible damage.

User interface

Operating the CMA18 Portable is a simple and straightforward procedure. All control buttons and switches are located in the left side of the chassis and all input/output interfaces at the bottom. After you power on the device, you can use the input selector button to select the desired source. (4.4mm Balanced Analog in, 3.5mm Analog in, optical, USB and Bluetooth). You can listen through balanced or single ended wired headphones and earphones. A gain switch is used to select between high and low according to the load. Volume level is adjusted with the aid of two buttons. You can increase/decrease the volume in single steps or continuously. Using the hold switch you can lock the device to avoid accidental actions.

The CMA18 Portable is not compatible with an application for further customization and doesn't include features like an equalizer or digital filters.



The LEDs

When in use, the amber-colored notification LEDs will display the current working status. At the upper part of the front face there are three parallel rows of LEDs. First row are three status indicator LEDs for displaying REC function (red), Gain high or low (red or amber) and input Data rate (red for high and amber for standard resolution). The second row are the five source indicator LEDs: Balanced, AUX, USB, OPT and Bluetooth. The third row are the Battery/Volume indicator LEDs. Four LEDs in total for %25, %50, %70 and %100. With the device switched off and charging, the LEDs will display the charge level. With the device switched on, the LEDs will display the volume level. Short pressing the power button will instantly display the remaining battery level.

At the bottom of the front face there is an extra row of four LEDs that display how many SiP modules are currently working. There can be either two for the single ended output or four for the balanced. An extra sole LED at the bottom left side is for displaying USB connection status.

Too many LEDs simultaneously working, that can't be dimmed or switched off, make the CMA18 Portable look like a Christmas tree. Furthermore, the lettering around the LEDs is barely visible so the user must memorize what is actually displayed.

Battery

The device runs from its own, 4300mAh battery so it will not drain the battery of the host device and additionally it gets isolated from any electrical noise. The battery doesn't support fast charging and needs about 3.5 hours for a full charge. Questyle promises about 10 hours of running time which is a little optimistic since I never got more than 6-7 hours from the balanced output at low gain with high resolution material and the Bluetooth switched off.

You can charge and use the device at the same time. To manually enable “Charge and Play” mode when connected to a USB playback device, long press the Function Button for approximately 4 seconds. The Battery Indicator lights will illuminate and flash, indicating the CMA18P is charging, and audio playback will continue uninterrupted.

Accessories

The package includes Lighting to USB type-C, type-C to C OTG cables, a longer type-C to C charging cable, a type-A to C adapter and a 3.5mm to optical connector. Documentation includes a quick start guide and the warranty card. A luxurious protective case is available as an optional ($49) purchase.



Power output with comparisons

The CMA18 Portable can do 1Wpc/32Ω with 2A peak current from its balanced output thus making it quite powerful for a portable, battery powered device. For the sake of comparison, the Chord Mojo 2 is rated at 600mWpc/32Ω (single ended) and the FiiO Q7 at 1.5Wpc/32Ω that doubles at 3Wpc/32Ω with the external power supply. Of course, the FiiO Q7 is considerably bigger than the CMA18 Portable and needs an external power adapter to reach its maximum power. So let's compare with the FiiO Q15 which is more compact and it only needs a phone charger to enable the desktop mode. The power rating of the Q15 is 1Wpc/32Ω with the internal battery and 1.6Wpc/32Ω with the desktop mode enabled. As we can see, they share the same power output under battery mode but the Q15 can do better with the power adapter. However, the Questyle CMA18 Portable is a slimmer, less heavy and more pocket friendly device.

Associated gear

The Questyle CMA18 Portable is very skilful driving a diversity of headphones except some really difficult ones. During the review, I used the Meze Liric 2, Focal Clear Mg and HIFIMAN Arya Organic without any issues. The CMA18 Portable drives them with great dynamics and plenty of headroom. The CMA18 Portable is also capable with high Z headphones, like the Sennheiser HD660S2, but the truth is that it really excels with lower Z loads as it can provide considerably more current than similar competitive devices.

Noise floor is very low but the CMA18 Portable is not dead silent. With very sensitive earphones, like the FiiO FX15 and the Soundz Avant, you can hear some background noise but everything else is completely silent. Thus said, the Questyle CMA18 Portable has a blacker background than the Chord Mojo 2 but it is not as dead silent as the FiiO Q7.

As per usual practice the CMA18 Portable was left playing music for about 100 hours before listening evaluation. During the review, I used headphone and earphone cables made by Lavricables to ensure maximum transparency.



Audio stuff

The sonic performance of the CMA18 Portable is nothing short of spectacular. Questyle promises desktop-like performance and the CMA18 Portable really delivers by successfully bridging the gap between the Questyle M15i and their desktop flagships. The CMA18 Portable bears Questyle’s house signature, a blend of neutrality with a nice warmth, and it manages to sound a bit more musical and organic than the other members of the Questyle family. The AKM DAC chip matches exceptionally well with the current amplification modules in a combination that delivers engaging and full bodied sound backed by strong technicalities and transparency.

The bass is visceral and weighty but still fast, tight and controlled with exceptional clarity and definition. The dynamic behavior and the physical impact of the Questyle CMA18 Portable are reminiscent of a desktop amp rather than a battery powered one. Pair it with a transducer that is within its power limits and you will be rewarded with powerful and thundering bass performance, the CMA18 Portable will definitely make your headphones sing like a pair of good speakers.

The mid-range is harmonious and melodic but never lacking in transparency and fidelity. Colorful harmonies and rich overtones are weaved together to offer a melodious sound that never fails to engage the listener while it excels in producing instruments and voices with a natural timbre in a lifelike manner.

The treble is extended, crystal clear and luminous, highly resolving and refined but not bright or fatiguing. Detail retrieval is excellent but the presentation doesn't veer towards analytical or sterile. The timbre is realistic and devoid of any metallic sheen, there are only a few instances where you can spot some traces of digital glare which are mostly dependent on the recording rather than the DAC itself. The CMA18 Portable is far from sounding dry or clinical, the sound is natural and not artificial with textures that are full bodied and not lean.

The soundstage of the CMA18 Portable is one of its best strengths as it can make your headphones sound big and expanded. Wide and spacious but not artificially stretched, it offers a holographic and immersive soundscape with great depth layering, laser sharp imaging and plenty of ambient information. The Questyle CMA18 Portable is one of the most accomplished portable DAC/amps for listening to large scale classical music, especially when paired with an equally capable headphone.

Comparison with the Chord Mojo 2

The Chord Mojo 2 (about 600-650$) is one of the most popular battery powered, portable USB DAC/amps. A well made device with a rather unique appearance and a somewhat awkward user interface. In terms of connectivity it supports USB, coaxial and optical digital inputs with two, single ended, headphone outputs that can be used simultaneously. It doesn't support Bluetooth connectivity (but you can buy the Chord Poly to add not only Bluetooth but also WiFi server reception) and it does have a transparent (lossless) digital signal processing EQ and crossfeed functions while you can also charge and play at the same time. On the other hand, the CMA18 Portable has a more friendly interface, it offers higher power output with a blacker background, it supports ADC recording function and is more compact.



In terms of sound signature, they are not that different, the Mojo 2 is a neutral and very transparent audio source with a touch of extra musicality and a bit of warmth. In a side by side comparison though, the Questyle CMA18 Portable produces a more effortless and naturally flowing sound with a bit more realistic and organic timbre. The Mojo 2 is the most transparent of the two, with deeper detail retrieval and an enhanced sense of clarity. It also images a little better but it doesn't sound as holographic and immersive as the CMA18 Portable.

Conclusion

The truth is that the Questyle CMA18 Portable is rather expensive than some of the competition but it justifies the premium price tag thanks to the impressive sonic performance, many features, excellent craftsmanship and the slim design. If you need a battery powered USB DAC/amp that is compact but still powerful enough and offers the best possible sound quality then look no further than the Questyle CMA18 Portable.

The review sample was kindly provided free of charge in exchange for an honest review.

The price of the Questyle CMA18 Portable is $799 and can be ordered from Questyle online shop.

Review Of The Questyle CMA18P​

Introduction​

Questlye is a Chinese company focused on researching and creating high-tech lossless audio systems with exquisite sound aesthetics and a comfortable listening experience. The company began creating headphone amplifiers in 2012, when it released the CMA800, and more recently, the CMA18P, M15i, and M12i. The company also released a lossless audio IEM. Personally, I bought their M15, which I loved for its design, form factor, and, most importantly, sound. At the time, there was no other dongle dac that sounded as clear and transparent. I was lucky enough to get my hands on CMA18P, their battery-powered portable DAC/AMP, but before going with the review, I'd want to clarify a few issues.

Disclaimer​

*Since this unit tour was organised by the kind people at Questyle, I am grateful to them. And as I've said in all of my evaluations, the same is true for this one: all of the concepts I've expressed below are entirely my own, original ideas that haven't been influenced by anyone else. If interested, go to this link.
*I am not associated with the connection, and I receive no financial assistance from anyone.
*For the remainder of the review, I will refer to this device as “CMA18”
*Finally, I will only evaluate the CMA18 based on its performance, even though I will explain how it feels and seems physically and aesthetically.

Specification​

The CMA18 includes four sets of patented PCT-class current-mode SiP chips capable of producing up to 5W of peak power, along with the XMOS XU316 platform and AK4493 DAC chip for HD D/A conversion up to PCM768/DSD512. It has two stereo line-in inputs (3.5mm AUX IN and 4.4mm BAL IN) for analog-to-digital recording, with monitoring via 3.5mm or 4.4mm outputs and seamless USB connection. It features a 4300mAh lithium battery for over 10 hours of battery life, MFi certification, and compatibility with multiple interfaces. Questyle's 3.5mm-RCA and 4.4mm-XLR cables allow connections to 2-channel Hi-Fi devices for home audio or monitoring purposes in recording and musical production. More technical specifications are mentioned below.

USB Playback:
Maximum support PCM768kHz/32bit
DSD Native: DSD64, DSD128, DSD256, DSD512
DSD Dop: DSD64, DSD128, DSD256
Supports:
Win XP / Vista / Win7 / Win8 / Win10 / Win11
/ Linux / Android / HarmonyOS / macOS and iOS
USB Recording:
Fixed 48kHz/32bit stereo recording
OPTICAL:
Supports 44.1kHz, 48kHz, 88.2kHz, 96kHz, 192kHz/24bi
BLUETOOTH:
Supports SBC/AAC/aptX/aptX-HD/LDAC D/A Convert
Maximum headphone output power:
BAL:1000mW@32Ω
THD+N:
<0.0003%@20mW，300Ω
SNR:
>120dB

Design And Aesthetics​

The CMA18's body resembles a flat block or numerous M15s stacked together. The frame is sandblasted aluminium, the front panels are glass with a gradient dot pattern, and the back has glass slapped on it. On the left side, there are four buttons and two toggle switches, and four output jacks with a USB-C OTG connector are located below the device. The buttons are used to move between functions while also acting as a volume rocker, hold and power button, while the toggle switch is used to change gain levels. When the device is turned on, the LED lights illuminate according to the function being used. Overall, the object has a computerized vibe, reminiscent of 1990s electrical equipment.

Usage ​

During my use, I discovered that these were not easily pocketable, but I was able to fit them comfortably in my pockets. The nicest aspect is that the form and design are not larger than my smartphone, and it provides a stronger grip when attached to the back of my smartphone. When it came to exploring all of its functions, I was only able to fully utilize the USB and Bluetooth modes, where the Bluetooth connection was quite dependable. Also, I usually used IEMs, but I never needed to use high gain, thus I never had any difficulties with power or SQ. Like I was with my M15, I am a bit concerned about the glass over it, but I have never heard of any quality concerns with M15, so I have great expectations with CMA18 as well. With my usage at regular gain and simply utilizing IEMs, I was able to achieve approximately 10 hours of use, which is what one should expect from a premium product. Finally, these are quite portable to utilize.

Sound Impressions ​

IEMs​

Thieaudio Prestige LTD

Prestige LTD is the very reason I am now able to find the truth in my musical dreams; I have never heard another IEM that ploughs your ears with faith in each note, no matter how those notes should sound and nurtures your senses with dynamics and presentation as if I were hearing reality. Previously, I owned the Monarch MKII, which established what one would expect, but once the prestige's magic began to flourish, I knew I could explore so much more with it, especially when it came to the air and presence of each nuance the notes were able to grasp over and tingled my senses. To summarise the prestige's response sounds as if the Monarch MKII were given steroids and enhanced the upper frequencies in all directions with better authoritative flow in the lower response. The response is neutral with sub-bass boost, similar to the Monarch MKII, with the exception that the notes are airier and more revealing than any other IEM before this era. However, the thinner notes and excessive clarity provide obnoxious features that expose bad mixing and recordings, which were highly obvious when heard on my V6 but smoothed out on my WM1A, indicating source dependence.



When I listened to this pair, it seemed really clear and fluid. The notes hit close together, capturing the listener's attention and keeping them interested. The soundstage sounded near, yet full of details that were easily pushed. The stereo image was improved by arranging the notes precisely and ensuring that the notes were distinguishable. The vocals in the higher section shine brighter, and the instruments have an added zing. Female voices and percussion, in particular, have an alluring quality that makes the music seem engaging.

Thor Mjolnir MKII

Mjolnir is a very bassy set that has a lot of sub-bass emphasis. The treble and upper mid-range are also very forward in the mix. The upper treble has great extension as well. The bass is very punchy and boomy while acting fast. Mjolnir is a great V-shape-sounding IEM with a different approach to explosive bass that has better technicalities, especially in this price range. The stage is great with a nice surrounding stage and depth where the separation of each element sounds distant enough to procure space to breathe and distinguish themselves. The attack and decay of the driver capability are really quick and perform great. The vocals may feel lean and sparkly, but the warmth or the fuller experience is something that these lack. The bass response does vary from source to source whether I listen to a warm source or a neutral one, the bass becomes either overwhelming authoritative or both.



While listening to this pairing, The smooth response sounds clearer since the vocals seemed more engaged in the mix and the instruments sounded less emphasized but more detailed. The overall approach of the response has improved. The bass sounded controlled, with a more textured bottom that helped to distinguish each note in the low end. Normally, the response does not sound as cohesive, but this pairing did make it seem nicely balanced. However, I did notice some white noise in the background on both analog outputs.

7Hz Aurora

Trust me when I say that Aurora is a literal detail monster, as every aspect of the presentation oozes out details and clarity with a versatile tuning that allows the intricacies and nuances to shower over the mix, bringing excellent clarity and transparency to the presentation. Though I notice that the existence of such notes results in sharp characteristics, I have never experienced a metallic nature. The crispness and air in the treble area, as well as the lively tone of the midrange, combined with a large stage that allows notes to breathe and sound full, result in remarkable detail retrieval. The nicest thing of the entire response is that the definition and tonal balance are nicely established, resulting in a lean yet coherent sounding presentation. If I look at the graph, it appears frightening with peaks and dips over the treble area, however such a presentation produces a vibrant and enticing response that isn't overly bright while also including crsip and the sparkling aspect of the notes. On the other side, the midrange sounds broader and clearer without adding hotness or peakiness to the mix, while the bass may become a touch too controlled but still present enough to make the response feel full-bodied.



Aurora's response was able to have the appropriate breadth and depth when listening to this pairing since the response was presented more frontally and backward. The vocals and instruments sounded more expressive than previously; with CMA18, the refinement in the notes increased in terms of details and contrast, providing more transparency and linearity throughout the response. The notes were clearer and revealed certain elements.

Rose Technics QT-X

QT-X offers a mid-centric and neutral tone, with a focus on the sub-bass and an overall clean sound. When I first started listening to them, I noticed that whichever source I used changed the quality of the sound without affecting the tuning, which made me understand how versatile they are in terms of technical aspects. The sound is characterized by its cleanliness and transparency, with a particular emphasis in the midrange that gives the vocals and instruments a spacious and well-defined presence. While the graph may indicate that the treble lacks energy and the bass is lean, the tuning of this IEM actually allows the treble to sound expansive and smooth without being dark, and the bass to provide good depth and presence. However, there is a slight lack of warmth and note weight in the mid-bass region that is noticeable throughout the sound signature. Finally, I feel the response has been properly calibrated to sound neutral and accurate, particularly in the midrange, rather than offensive or bright.



While listening to this pairing, the response sounded revealing, but not in an energetic way, but rather in a more soothing manner, with better contrast in overall reaction. The treble sounded more comfortable, with better extension. The voice and instrumentation both sounded more direct and appealing. The whole response sounded clearer and airier than previously.

Tracks​

Millet - Anytime Anywhere
Anri - I can’t stop the loneliness
Kohana Lam - A Few Sentimental
Kohana Lam - Loving Me, Loving You
Uru - Kimino Shiawasewo
Uru - Kamihitoe
Kujira Yumemi - Kenka
Majiko - Kokoronashi
Anly - Sukinishinayo
Kohama Lam - A Few Sentimental
Kohana Lam - Loving Me, Loving You
Miliyah - Kono Yumega Samerumade
Rokudenashi - The Flame Of Love
Yu-Peng Chen - A New Day with Hope
Yu-Peng Chen - Another Hopeful Tomorrow
Yu-Peng Chen - For Riddles, for Wonders
Valentino Khan - Satellite
Kai Wachi - Happier By Now
Jawns - Erotica
ISOxo - how2fly
Kai Wachi - Happier By Now
Weeknd - Popular
YUNGBLUD - When We Die(Can We Still Get High)
Bring to Horizon - Kool-Aid
Middle Kids - Bend
FLETCHER - Leads Me On
Loathe - Aggressive Evolution
The Weeknd - Save Your Tears
Sigrid - Burning Bridges
AURORA - Black Water Lilies
AURORA - Runaway
X Ambassadors - Renegades
Lupe Fiasco - Words I Never Said
Macklemore & Ryan Lewis - Can’t Hold Us
Gotye - Somebody That I Used To Know
Jay-Z - Run This Town
Lady Gaga - Poker Face
Lady Gaga - Just Dance
Ladytron - Ghost
Travis - Love Will Come Through
LINKIN PARK - Somewhere I Belong
DJ Shadow - Six Days (Remix)
Hoobastank - The Reason
Ricky Martin - I Don’t Care
Tool - 7empest
Tool - Vicarious
A Flock Of Seagulls - Space Age Love Song
Zack Hemsey - Vengeance
Elton John - I’m Still Standing
The Moody Blues - Nights In White Satin
Micheal Sembello - Maniac
Guns N’ Roses - Sweet Child O’ Mine
A.R. Rahman - Kun Faya Kun

Conclusion​

To summarize this evaluation, CMA18 is quite competent and filled with features that will completely gratify its user. I believe the power and sound quality it provides make it a highly practical device as a portable product, and in terms of sound performance, I have never heard anything that sounds this cohesive and smooth while improving on details and clarity. The whole presentation is synergistic and linear, making it versatile and mature-sounding portable DAC/AMP. As a result, I believe Questyle done an excellent job with CMA18, and I recommend them.