Questyle M18i

QUESTYLE is one of the well-esteemed audio companies around as they brought forth some of the highly acclaimed audio equipment that are used on both professional and non-specialised side of audio appreciation. Their well-regarded reputation as producers of high quality audio products assures that every product that they release on the market will be solidly built, easy to operate and will have some excellent components sourced from reputable audio solutions.



I previously published a few products from them and all of them are from their M series line-up models which are all portable headphone DAC/Amplifiers also known as USB DAC dongles. And now, what I have here and will be the highlight of this product review is the latest generation of the M Series models, The QUESTYLE M18i.



Unlike the previous models which are more of a standard portable headphone DAC/Amplifiers, this one has some new features that makes it more advanced as QUESTYLE added some of the latest breakthroughs of mobile audio innovation, particularly on wireless technology. And with some added features, this device is relatively a bit larger just to accommodate some functionalities that will deliver a worthwhile audio experience.



The QUESTYLE M18i still shares some similar design language and form factor with the previous M-series albeit it incorporates a screen beneath on its tempered glass panel, an extra USB-C for charging (yeah, this is quite a unique feature) and finally, some physical buttons. The overall frame itself is made of a high quality CNC-milled aluminium alloy that underwent an anodisation and sand-blasting process to achieve its matte-like finish on its surface for better grip, less fingerprint magnet and resistant from light scratches, and like all M-series, it has black colourway with rather minimalist design on its aesthetics.



At the front part where the glass panel was situated, its appears that like M-series, it uses a tempered glass panel provide by Kunlun and beneath of it was a OLED screen panel in which display a simple UI for volume control, gain mode, battery level, sampling rate with its audio signal format and device modes. On the back part, there are no other hardware features aside from the Questyle brand and the brand model print that was etched on it.




On the long side panel, there is a USB-C port (input charging only) that supports USB charging while using the other USB-C port for decoding at the same time which is more convenient in my opinion. And at the opposite length panel, there are some hardware key buttons for volume controls and gain/MFB mode and a power button along with toggle switch for device modes for PC, Mobile and Bluetooth DAC/Amp connectivity as it has an advanced optimisation for power supply for reduced power consumption for each specific mode along with a built-in mic input. The buttons also support some basic media playback controls like play, pause and next via double pressing on playing tracks, and also on calls like answer, reject and disconnect.




The gain mode, we can switch on either low gain more or high gain mode while its volume amplitude rating can deliver up to 60 steps with an incremental adjustment on each level. On the power button, if we press it, it will be on the stand by more which makes the UI print a bit dimmer.



And then, at the side vertical angle part, like most of the previous generation of M-series, it has a dual headphone jack set-up of varying output types, a standard 3.5mm single-ended and a 4.4mm balanced output. And on its opposite side, this is where the USB-C port can be connected to other devices with compatible connectors, like smartphones, tablets, laptops and PCs along with other devices as long as it supports USB audio.



Unlike the top models of the M-Series that uses a flagship USB DAC, The QUESTYLE M18i uses a rather standard ESS Mobile DAC, the ES9219Q which is proven and pretty consistent on its performance particularly on decoding performance and power output. The DAC chip itself is quite efficient as it has a low power that can process up to 32-bit with a two channel stereo output along with its advanced circuitry architecture for improvements of dynamic ranges,frequency filters and sampling modes in tandem with its capable built-in SABRE headphone amplifier.



Like all QUESTYLE products, it still utilises its patented technology which is its vaunted CMA module technology. This one is a type of a SiP module with functional quad audio amplification engines that eliminates negative signal feedback due to better bandwidth, huge improvement of its dynamic signal processing and ultra-low distortion rating will deliver an excellent clarity, detailed and accurate sound reproduction which has a similar peak performance of a Class A amplifier.


As I mentioned before about some of its newly introduced features, The QUESTYLE M18i also includes some wireless connectivity like bluetooth and microphone. The Bluetooth chip of this device is a 5.4 version provided by Qualcomm which improves its Bluetooth Low Energy technology along with improved reliability and stable connection, more efficient on transmitting high data transfer and better energy management for lower power consumption compared to its previous generation. Since this is a Qualcomm component module, it can support advanced bluetooth codecs like apt-X adaptive, apt-X HD, LE Audio and LDAC aside from standard bluetooth codecs like SBC and AAC. This device also utilises an latest generation of Infineon MEMS microphone that supports HD calls with its AI assisted noise reduction technology and noise filter for better SnR, low distortion and better sensitivity matching for high fidelity voice quality.



Another thing is that this device also has a built-in 500mAh lithium-polymer battery whose performance is very underwhelming that it can only wireless bluetooth playback for over two hours on low gain mode and much lesser on high gain mode.


On its product packaging, it has a simplistic presentation and still shares similar content layout with the previous M-series models. Aside from M18i headphone DAC/Amplifier, it also includes a short fabric-sheathed type-C to type-C cable, USB type-C to type-A adapter and paperwork like user’s manual with different languages and warranty card.



The QUESTYLE M18i is a plug and play peripheral device that can support all known major devices on both hardware and software aspects. On the hardware, it's compatible with all known modern computing devices as long as it has a USB type-C connection that supports USB Audio. Another good thing is that it has an Apple’s MFi certification that it can be used across its well-developed ecosystem with its own software and hardware compatibility.


As for its software side, here is the table of lists on its operating system interoperability.


In this review, I will use my Android phones 9 (Android 9.0 up to the 13) and a laptop with a LINUX MINT OS.



The QUESTYLE M18i can deliver a strong power output that can drive some of power hungry cans and IEMs with special drivers that need better amplification to sound properly. With some of its newer components that if it was paired to some overly sensitive IEMs, there will be no worrying about unwanted noise floor distortions.



List of headphones and IEM earphones that will be used on this test.

• LETSHUOER S12 2024
• LETSHUOER EJ07
• LETSHUOER EJ09
• SIVGA ANSER
• SENDY AIVA 2
• 7TH ACOUSTIC SUPERNOVA

As for its tonal performance, it appears that QUESTYLE M18i delivers a bit of a warmish-neutral sound profile as it has a noticeable more textured compared to the previous M15 models which are known for their balanced-neutral type of sound that makes them more ideal tool on audio reviewing.




LOWS/BASS:

This device conveys a more firmness and tactility on the bass response to sound more punchy, more denser and impactful that pairing it with IEMs with more emphasis on low frequency will add more dynamic character. It can deliver a deep and reverberating quality on its sub bass presence that were generated from low-tuned string instruments like bass, guitars, double-basses and octobasses, and also on percussives drum machines and synthesisers.

And on its mid bass, apparently that if it was paired to more neutrally-tuned IEM earphones, it somehow adds a bit more texture as it give more body on deep male vocals as it add richness, resonance and sombre sound but not to the point that it sounds too boomy and authoritative. And also on instruments, particularly on bass-clef ones, bass guitars will have more dusky sound, double-basses sounds more broader and resonant, bass trumpets sound fuller with a more darker timbre and a bass kick drums’ strikes will have a bit fuller and sonorous sound.


MIDRANGE:

As it maintains a neutral presentation, I can certainly pinpoint that there is a little bit of warmth as it adds more depth and richness on vocals and instruments to sound organic as possible while maintaining a clean and detailed sound quality on them. On the sound quality of male vocals, baritones have smooth and rich sound while the tenors have that brassy and ringing quality on their voices, and then, a tender and clear falsettos of countertenors. For female vocals, a richer plushy sound on contraltos, a velvety and coppery sound on mezzo-sopranos, and then, a more satiny and creamy sound on soprano vocals.

About instruments, on strings, a bit buttery sound on guitars, a sensuous and silky sound on cellos and a sweet and softer sound on violins. On the woodwinds, it somehow maintains the clear and light sound on piccolos, a graceful yet brilliant sound on concert flutes, a mellow and rich sound on clarinets and a sonorous and reedy sound on saxophones. The brass instruments, in corresponding order, are full, rounded and sound on trumpets, trombones and horns. As for the remaining instrument type, the percussion ones, a harder and precise sound on snares, as sonorous and full sound on every stroke on field drums, a rich and resonating sound on tom-toms, and a deep and substantial sound on kettledrums. And lastly, the pianos seem to have a balanced tone as they have rich, sweet and clear sounds on them.


HIGHS/TREBLE:

The treble quality on this one delivers a lustre and sheen presentation with sufficient amount of airy enough to highlight the clarity and definition on vocal articulation and a sharper attack of both rhythmic and percussive instruments. If it is paired on some IEMs with a neutral-ish bright sound signature, it somehow adds a sufficient amount of air without emphasising too much on the brilliance section on the high frequency region.

This device somehow adds a bit more brilliance, silvery and shimmer on respective treble-clef instruments; cymbals, glockenspiels and celestas.


OVERALL TECHNICALITIES:

Like all M-Series that I have tested in which are remarkable in terms of technical performance, QUESTYLE M18i is no exception as it also shares those impressive qualities that defines these portable headphone amplifiers. It is capable of projecting a fairly spacious sound field dimensions with a well-layered black background soundscape.

It has pretty excellent on resolution capabilities on how it contrast between macro-dynamics and micro-dynamics as the former will have a more concrete dynamic range as it how it highlights the gradual volume phase from soft and quite levels up to the loudest level on instrumental passages and chorale lines, while on the latter, it is able to show some micro-details, nuances and subtleties in a sonic gradient with likes of notational attack of instruments, vocal ends and reverb tails.


PEER COMPARISONS:

QUESTYLE M15/M15i

• It shares similar design language with the M18i but it has a compact size on its rectangular form factor.
• They don't have an OLED Panel to display the current status but on its tempered glass, we can clearly see its internal parts like circuit board, transistors and ICs.
• It uses an LED indicator to determine its current sampling rate.
• Unlike the M18i, it doesn't have any physical key buttons for volume control and basic media playback control and its toggle switch has a different function as it is used to adjust gain modes.
• It doesn't have a built-in battery, so it doesn't have any bluetooth connectivity at all nor an integration of a HD microphone to receive calls.
• It uses a flagship grade USB DAC chip from ESS, ES9281AC.
• The M15 can process and decode up to 32-bit/384khz on PCM audio and up to DSD256 on DSD format, The M15i is even more capable as it can process up to 768kHz on PCM and up to DSD512 on DSD format.
• It has a dual headphone jack with different output and uses a USB-C as its connector to a host device.
• The M15 has a balance-neutral sound profile with some slight emphasis on high frequency section while the M15i has a tad warmer sound profile.
• It has an excellent technical capability from soundstage size projection up to the pretty resolution on its resolution capabilities although the M15 has a slight edge on micro-dynamics as it has a bit sharper definition on micro-details, grains and nuances.

HIBY W3II

• It has a smaller and slimmer profile compared to the M18i and its frame is made of a high quality PC shell with a built-in shirt clip that makes it lighter.
• It doesn't have any screen but rather a panel with some graffiti designs on it.
• It has an LED indicator for power and bluetooth connection status.
• This device has three button keys for power and volume control, it also works as basic media playback control.
• It has built-in battery with a power capacity of 320mAH but to my surprise, it has longer playback time on both standard Bluetooth formats and advanced Bluetooth codecs as it can play up to 10 hours of continuous playback and a lesser time duration on advanced Bluetooth codec like apt-X HD and LDAC around 7-8 hours.
• It also has a built-in HD microphone like the M18i which also has clear voice quality.
• Aside from its Qualcomm Bluetooth chip, it also has a NFC feature.
• It has a proven Cirrus Logic DAC chip, CS43131 that can process up to 32-bit/192kHz with an output voltage of 1.75Vrms in 98mW of power output.
• It has only one type of headphone jack which is a standard 3.5mm.
• It has a strong software as you can utilise its more functionality via HiBY Blue App.
• It has a warmish-neutral type of sound that makes it a bit closer to analogue profile from the old generation of high fidelity sound.
• It has a pretty decent technical performance from above-average soundstage size, good layering on its soundscape and acceptable resolution capabilities.
• This one is even way cheaper as it was priced around US$40 at the time of its release.

As I conclude this product assessment, The QUESTYLE M18i is definitely a big upgrade from its predecessors as it has some added operationalities that makes it more convenient to use either on a typical plug and play use or in wireless bluetooth transmission mode. For sure that there are some noticeable issues like its playback duration as I’m quite dissatisfied with its performance as it has a rather short uptime of just over 2 hours along with its longer charging time. Aside from its meagre battery performance, I wish that it has some built-in basic EQ just like devices of similar profile. Nevertheless, I will still recommend this device who is looking for excellent and refined tonality with exceptional technical performance, along with support of more advanced bluetooth codecs and a solid build quality that makes it more premium.

The QUESTYLE M18i is now available on QUESTYLE’s official store and you can see the link that I have provided below.

LINK: https://questyleshop.com/products/questyle-m18i


For more QUESTYLE product reviews:

◼ QUESTYLE M15

◼ QUESTYLE M15i


SPECIFICATIONS:

MODEL: QUESTYLE M18i
MATERIAL: CNC-milled anodised Aluminium Alloy
DAC CHIP: x2 ESS ES9219Q
DECODING CAPABILITY: (PCM) 32-bit 44.1 -384kHz/ (DSD) DSD64-256
BLUETOOTH VERSION: 5.4
BLUETOOTH CHIP: QUALCOMM
BLUETOOTH SUPPORTED CODECS: SBC, AAC, aptX,aptX HD, aptX Adaptive, LE Audio, LDAC
CALL FUNCTIONALITY: Supported via Infineon microphone module
BATTERY CAPACITY: 500mAh
HEADPHONE OUTPUT PORT(S): 3.5mm single-ended, 4.4mm balanced
POWER OUTPUT: 28mW at 300 Ohms (4.4mm balanced output)
FREQUENCY RESPONSE: 0.1dB (20hz-20kHz), 2dB (20kHz-80kHz)
THD: 0.0002%
OVERALL DIMENSIONS: 75mm x 35mm x 14.5mm




TESTING TRACKS: ( * = 16-bit FLAC, ** = 24-bit FLAC, *'* = MQA, '*' = DSD, *'= .WAV)

Alison Krauss -When You Say Nothing At All *
Jade Wiedlin - Blue Kiss**
Led Zeppelin - When The Levee Breaks **
Mountain - Mississippi Queen *
Queen - Killer Queen **
Guns N' Roses - Patience *'*
Eric Clapton - Tears in Heaven '*'
Sergio Mendes- Never Gonna Let You Go '*'
Pearl Jam - Daughter **
Roselia - Hidamari Rhodonite *
Assassin - Fight (To Stop The Tyranny)*
Celtic Frost- Visual Aggression *
New Order - Blue Monday *
The Corrs- What Can I do (unplugged version) *
Jimi Hendrix Experience - Voodoo Child *
The Madness- Buggy Trousers *
Metallica - Motorbreath **
Mariah Carey- Always Be My Baby *
Destiny's Child - Say My Name *
Malice Mizer- Au Revoir *
Mozart - Lacrimosa *
New York Philharmonic Orchestra - Dvorak- Symphony 9 " From the New World." *
Eva Cassidy - Fields of Gold (Sting cover)*
Michael Jackson - Give In To Me *
Exciter - Violence and Force *
Diana Krall - Stop This World **
Debbie Gibson - Foolish Beat *'*
The Sisters of Mercy – Lucretia My Reflection**
Suzanne Vega – Luka **
Lauren Christy – Steep *
Ottoman Mehter - Hucum Marsi *
Diana Damrau - Mozart: Die Zauberflöte*


P.S.

I am not affiliated to @Questyle nor receive monetary incentives and financial gains as they provide me a review unit for an exchange of factual and sincere feedback from yours truly.

Once again, I would like to send my gratitude to the Questyle Audio Rep for providing this review unit. I truly appreciate her generosity and trust towards me and other reviewers.

The Questyle brand requires no lengthy introduction. The brand is renowned not only for producing award-winning audio devices like the CMA18 Master and the CMA18 portable, but also for pioneering the patented Current Mode Amplification (CMA) technology.



Current mode amplification (CMA)

It is widely recognized that processing high-resolution lossless audio and driving amplifiers typically requires significant energy. While this poses no issue for AC-powered Hi-Fi systems, it becomes a challenge when designing mobile devices. Questyle’s patented Current Mode Amplification (CMA) technology was specifically developed to address this problem.

As the name suggests, CMA technology processes the audio signal as a current rather than a voltage, using discrete transistors in the circuitry. A Current Mode Amplifier consumes just one-tenth of the power of conventional systems while offering 10 times the bandwidth and dynamic signal processing capabilities, all with ultra-low distortion.

Questyle has also created a range of audio SiP modules, such as the MA2430 chip, which integrates Current Mode Amplification with full-link lossless audio signal processing. It operates with a minimum voltage of 2V and a current draw of only 3mA—less than half the power consumption of a pair of TWS earbuds.

Questyle M18i

Questyle's lineup features three portable USB DAC dongles: the entry-level M12i, and the M15C/M15i, which are enhanced versions of the highly praised M15. Their latest addition is the M18i, a portable USB DAC dongle that stands out from the rest by incorporating its own internal battery and supporting wireless Bluetooth connectivity. The "i" in these models signifies that the device holds an official Apple MFi certification.



Technical stuff

The Questyle M18i is equipped with two ES9219Q DAC chips from ESS for audio decoding. In collaboration with ESS, Questyle has developed the TTA (Triple Decoding Architecture) DAC framework to push the M18i's performance to its peak.

The headphone amplifier is divided into distinct preamp and power amp stages, featuring two CMA SiP modules, which house four Current Mode Amplification (CMA) engines.

The M18i includes a dedicated 16-Core XMOS XU316 USB receiver, offering full compatibility with iOS, HarmonyOS, Android, Windows 10/11, macOS, and PSP gaming consoles. It supports high-resolution audio decoding up to 384kHz/32bit PCM and DSD256 via the USB Type-C input.

Additionally, the device is equipped with a Qualcomm Bluetooth 5.4 receiver, supporting AAC, SBC, aptX, aptX HD, aptX Adaptive, LDAC, and LE Audio decoding. In Bluetooth mode, the M18i draws power from its own battery.

For high-definition calls, the M18i features Qualcomm's cVc Generation 8.0 ClearVoice Capture technology, providing Advanced Noise Reduction to eliminate background noise and ensure clear sound delivery to the user.

Extra USB power input

The Questyle M18i features a dedicated USB Type-C port for power input, allowing you to charge the battery while using the device simultaneously. Once the battery is fully charged, the device switches to drawing power directly from the external adapter. Keep in mind that this function is solely for charging purposes and, unlike FiiO's desktop mode, does not enhance the M18i’s power output.



Non Audio stuff

The Questyle M18i features a rectangular chassis with a minimalist, industrial design reminiscent of the CMA18 portable and M15i. Crafted from CNC anodized aluminum, it boasts a smooth black matte finish, while the front panel is reinforced with tempered glass. Its rounded corners and edges ensure a comfortable grip.

Built with exceptional precision, the M18i exhibits no visible flaws, and its well-integrated buttons remain firm without any wobbling. Measuring 75x35x14.5 mm and weighing just 50g, it is both compact and lightweight, comparable in size and weight to other USB DAC dongles.

Unlike some other Questyle portable DAC/amps that showcase internal components through a transparent glass panel, the M18i features an OLED screen. This display provides essential information at a glance, including volume level, gain setting, battery status, working mode, and input sampling rate.



In use

The M18i offers three operational modes and features four push buttons along with a switch. The switch allows you to toggle between PC, Phone, and Bluetooth modes. The first button powers the device on and off and wakes the screen, while the second and third buttons adjust the volume. The fourth button, a multifunction button (MFB), serves as a gain switch and performs various functions in Bluetooth mode.

In Phone mode, the M18i runs on its internal battery, with the USB port used solely for data transfer, ensuring it does not drain the phone's battery. Similarly, in Bluetooth mode, the device functions as a wireless receiver and relies on its own battery for power.

In PC mode, the USB port handles both data transfer and power supply, utilizing an intelligent power management system that efficiently balances power distribution between charging the battery and supporting system operation based on the host device's current limitations.

Regardless of the mode, you can connect an external power adapter via the second USB Type-C port.

The M18i does not support a companion app and lacks an internal menu for adjusting audio settings or other parameters.

Bluetooth connectivity and performance

When Bluetooth mode is selected, the M18i automatically enters pairing mode and locks onto the highest-quality codec supported by the transmitting device. The active codec is displayed on the OLED screen.

In Bluetooth playback mode, the gain button does not function for adjusting gain dynamically; you must set the desired gain beforehand. Instead, a single press of the button toggles play/pause, while a double press skips to the next track. Rewinding to the previous track is not supported. Additionally, during an incoming call in Bluetooth mode, pressing the button answers the call, double-pressing rejects it, and pressing it again ends the call.

The Bluetooth connection remains highly stable within the same room, and the audio performance is exceptional, particularly with the LDAC codec. The sound quality is so impressive that only careful listening reveals the slight advantage of a wired connection.



Accessories

The included accessories are quite limited and do not justify the M18i’s price point. The package contains only a high-quality USB OTG cable and a USB adapter. Apple users will need to purchase a separate USB-C to Lightning cable, and the premium Questyle protective case is sold separately for $29.99. To enhance the overall value, Questyle should have included both a USB-C to Lightning cable and a protective case at no additional cost.



Power output and noise

Questyle lists the balanced output power as 28mW at 300Ω but does not provide specifications for 32Ω or 16Ω loads. In real-world use, the M18i proves to be quite powerful, easily driving full-sized headphones like the Sennheiser HD660S2, Hifiman HE1000 Stealth, and Meze Audio 105 AER. It is also well-suited for sensitive in-ear monitors, thanks to its virtually silent background and resistance to electromagnetic interference (EMI).

Battery Life

The M18i features a modest 500mAh battery, which provides a maximum of just 2 hours of operation, regardless of whether it is used in Phone or Bluetooth mode. At high gain, the battery level drops from 100% to 80% in under 30 minutes—an underwhelming performance that makes it impractical as a standalone battery-powered USB DAC dongle or Bluetooth receiver unless frequent recharging is an option. Additionally, the battery does not support fast charging and requires two hours for a full recharge.

Out of curiosity, I measured the device’s power consumption in PC mode and found it to be 0.26A with a fully charged battery. Given this relatively high consumption, it’s no surprise that the battery drains quickly.



Audio stuff

The M18i delivers outstanding audio performance, making it one of the best USB DAC dongles for those who prioritize neutrality and transparency. Its frequency response is perfectly flat, ensuring class-leading fidelity and precision without imparting any coloration to the sound.

Questyle has also expertly refined the typically aggressive treble of the ES9219Q DAC chip, resulting in a presentation that is crystal clear and energetic without becoming harsh or overly bright. The M18i excels in resolution and detail retrieval while avoiding a sterile or overly analytical sound.

While it may not offer the rich, organic, and analog-like warmth of some competitors like the Cayin RU-7 or iBasso Nunchaku, the M18i maintains a lifelike and natural sound with minimal digital glare. It won’t add extra warmth or tube-like richness to the music, but it adeptly reveals and enhances the harmonic complexity within a high-quality recording.

The CMA modules deliver an impressive bass performance, characterized by wide dynamic contrast, strong impact, and excellent technical precision. The bass is fast, tight, and well-controlled, with outstanding layering and separation. While the textures aren't overly visceral or weighty, they remain rich and engaging, avoiding dryness while maintaining elasticity and a lush presentation. The M18i offers a well-balanced performance—technical enough to satisfy discerning audiophiles while also delivering an exciting and engaging sound for modern music.

The midrange and treble are presented with remarkable clarity, strong presence, and excellent articulation, without compromising harmonic richness. The textures are sufficiently weighty, aligning well with the low-end, ensuring that higher-pitched instruments don’t sound thin or artificial. The timbre remains natural, free from metallic artifacts or clinical harshness.

The M18i delivers an impressively spacious soundstage that maintains a natural presentation, complemented by top-tier imaging and separation. While it may not be the most holographic DAC dongle available—the iBasso Nunchaku slightly surpasses it in this regard—it still provides an immersive and expansive experience with excellent depth layering.

In conclusion, the Questyle M18i pairs well with all types of earphones, including brighter ones, and complements all music genres. You can confidently use your most high-end earphones without the M18i being a limiting factor. However, keep in mind that its highly revealing nature makes it rather unforgiving of poor recordings.



Comparison with the FiiO BTR17

The FiiO BTR17 ($199) is the brand’s flagship USB DAC dongle, featuring an internal battery and Bluetooth connectivity, much like the M18i. While these two devices share several similarities, they also have distinct differences. The BTR17 is priced $149 lower and comes with a leatherette protective case as part of the standard package.

Slightly larger and heavier than the M18i, the BTR17 justifies its size with a 1.3” IPS color display, a multifunctional volume control wheel, and a higher-capacity battery that provides 7-8 hours of playback.

Although their core functions are similar, the BTR17 offers a true desktop mode that bypasses the battery entirely and boosts power output to 650mW*2/32Ω. Additionally, it is compatible with the FiiO control app, allowing users to fine-tune audio settings such as digital filters and utilize a 10-band lossless PEQ.

In terms of sound, the BTR17 maintains a neutral tuning but leans towards a brighter presentation, emphasizing treble more than the M18i. While it may have a slight advantage in technical performance and detail retrieval, it also sounds more clinical and sterile in comparison. Both devices excel in bass impact and dynamics, but the M18i delivers a fuller, more fluid, and slightly more organic presentation. The BTR17, on the other hand, has a more digital and artificial timbre but is also more transparent and clean.

Conclusion

The Questyle M18i is a fantastic USB DAC dongle, delivering outstanding wired and wireless performance. Its unique CMA modules expertly manage dynamic range, providing desktop-level driver control and impressive bass response.

Built with quality, the M18i is compact and lightweight, featuring a separate USB power input for added flexibility. However, its limited battery life and lack of customization options prevent it from being truly perfect.

That said, its exceptional sound quality more than makes up for these shortcomings. Instead of focusing on battery limitations, it’s best to see it as a high-performing USB DAC dongle with the added perk of running for a few hours without external power.

------------------------------------------------------------------------------

The review sample was kindly provided free of charge in exchange for an honest review. I don't use affiliate links. The price of the M18i is $349 and you can buy it from Questyle online shop.

Disclaimer: For various Google indexing reasons, most parts of this review have been processed with an automatic paragraph rewriting tool. However it reads exactly the same as the original content that is available in my website.

This is super short and to the point…

Sound: Really Great — Somewhere between the DC Elite and Kensei (in tonality and soundstage…more immersive than both).

Battery: Horrid — 1-2 hrs tops.

Power Management: Pitiful. I’ve owned two units and they both would not let me power the device off 90% of the time. The other 10% I could only do so by “interrupting” the circuitry by unplugging something, or toggling source switch.

Performance Otherwise: Terrible. There’s a half-second delay INTO the music every single track, regardless of device. Maybe a firmware update will help, but, again, I’ve owned two of these brand new and they both did the same thing on iPhone, iPad, or MBP (iTunes or Tidal).

I feel like most reviews were excited about the sound initially, as I was, and I could ignore battery life as I use it plugged in the vast majority of the time. But being a listener of a lot of prog rock/metal/alternative, to miss the first jarring notes of every single tune kinda made me wanna throw it across the room. I want to like Questyle, I really do. But their “18” portable series of products have seriously missed the mark in execution. The fact it’s already being discounted by $50 on Amazon, and few other retailers, is not a great sign this early into the release.