As a specialist brand with deep expertise in high-end Hi-Fi audio, Questyle introduces its latest flagship, the M18i Max portable DAC and headphone amplifier. Combining an uncompromising commitment to high-fidelity sound, desktop-class hardware architecture, versatile compatibility, and minimalist industrial design, it brings portable Hi-Fi enthusiasts, music lovers, and professional musicians a benchmark product that pushes the boundaries of sound quality in portable devices.
A comprehensive upgrade to the M18i, the new M18i Max retains its predecessor's distinctive high-end sonic character while advancing several core areas. A major focus is the power supply system, which substantially extends battery life and addresses a longstanding limitation of high-end portable listening. The improvements also raise its drive capability, dynamic detail, and sonic purity, delivering a significant step forward in both flagship sound quality and suitability for mobile use.
Purpose-built for premium portable listening, M18i Max is designed for everyday travel, commuting, mobile desktop setups, and outdoor listening. It is particularly well suited to a wide range of premium in-ear monitors, unlocking the full Hi-Fi potential of portable equipment. Without relying on a fixed desktop system, it delivers authentic flagship high-fidelity sound wherever you listen.
Bauhaus Minimalist Design
Premium materials and a distinctive flagship identity
M18i Max continues the refined, minimalist industrial design of Questyle's flagship family. Its classic Bauhaus aesthetic follows the principles of function first and less is more.
The CNC-machined metal enclosure has an anodized matte-black finish that feels refined and understated. A fully laminated, high-definition OLED display blends into the surface when switched off and shows essential listening information in real time, including sample rate, codec format, gain setting, battery level, and volume.
A transparent PCB window reveals the precise arrangement of the internal hardware, bringing engineering detail into the minimalist design. The result combines a highly portable form with premium craftsmanship and a recognizable flagship identity.
Intelligent Battery Management
Cleaner and more stable power with listening while charging
M18i Max comprehensively optimizes the power supply system, improving power purity, stability under load, and dynamic response. This provides a solid electrical foundation for flagship sound with an exceptionally low noise floor and finely resolved dynamics.
Questyle's intelligent battery energy management and voltage regulation adapt the power supply to different usage scenarios, preventing fluctuations in current from degrading sound quality. Listening while charging is supported in every mode. Improved battery endurance meets all-day portable listening needs, making high-end listening on the move more reliable and worry-free.
Dual ESS ES9219Q DACs and TTA Architecture
Flagship Combo DACs with a dual mono design and desktop class decoding
At the heart of M18i Max are two carefully selected ESS flagship ES9219Q Combo DAC chips in a dual-mono configuration favored by audiophiles. It incorporates Questyle's TTA three-tier decoding architecture, originally used only in high-end desktop equipment. Jointly optimized by Questyle's R&D team and ESS engineers, the hardware performs close to the limits of physical measurement. It supports high-definition decoding up to PCM 384 kHz and DSD256, covering the full range of mainstream lossless music formats.
M18i Max TTA decoding architecture
The TTA three-tier architecture brings warmth to vocals, delicacy to strings, and exceptional retrieval of subtle textures. Dynamics are controlled with finesse, while natural transitions between musical layers capture the smallest emotional shifts. Large-scale classical works, vocals and strings, and pop instrumentation all gain three-dimensional imaging, clarity, and richness, complementing the detail, transparency, and high resolution of premium in-ear monitors.
Proprietary Current Mode Amplifier SiP Modules
Low distortion and ample drive with excellent performance across the frequency range
M18i Max contains two of Questyle's specially selected, proprietary SiP amplifier modules, incorporating four patented Current Mode Amplification circuits. Backed by international PCT patent technology, the design achieves distortion as low as 0.0002% under an actual 300 Ω high-impedance load and delivers a peak output current of 1.5 A. Combined with TOREX's efficient, precision power management system, it offers powerful drive with finely nuanced tonal reproduction.
Core hardware
From low-impedance in-ear monitors and flat-head earbuds to high-impedance over-ear and planar headphones, M18i Max has the drive to realize their full potential. Bass extends deep with tight, powerful control; midrange vocals are warm and full-bodied; and treble is extended, transparent, and clean. Transients are crisp and controlled, while demanding dynamic passages remain composed, meeting the needs of high-end portable listening.
An Exceptionally Low Noise Floor
A clean sonic background that preserves the finest studio details
An upgraded precision circuit layout and enhanced power supply rejection enable M18i Max to achieve an exceptionally low noise floor of -130 dB. Against this dark, clean background, nearly inaudible overtones and delicate textures emerge clearly, preserving original studio details such as a singer's breath and the decay of instruments.
Bluetooth and USB DAC Dual Mode Operation
Bluetooth 5.4 with Snapdragon Sound and Sony LDAC certification
Lossless sound with wireless freedom.
M18i Max integrates lossless Bluetooth and USB DAC operation in one device, with freely switchable modes for listening at home, on the move, and during desktop monitoring. It features the latest Bluetooth 5.4 and holds both Qualcomm Snapdragon Sound and Sony LDAC certification. It supports AAC, SBC, aptX, aptX HD, aptX Adaptive, LE Audio, and high-definition LDAC at 24-bit/96 kHz. Even wirelessly, it delivers sound approaching the lossless quality of a wired connection, overcoming the sound-quality limitations of Bluetooth transmission.
16 Core XMOS Controller
Broad compatibility across platforms
The hardware platform uses a 16-core XMOS XU316 USB controller for extensive device compatibility. It supports iOS, HarmonyOS, and Android 5.1 and later. It also provides driver-free operation with Windows 10 18.3 and later, supports the full macOS computer range, and works with gaming devices such as PSP.
Apple MFi Certification
Stable and safe direct connections across devices
M18i Max is officially licensed under Apple's MFi program and strictly follows Apple's accessory power consumption and compatibility standards. Compatible with the full iPhone and iPad ranges, it avoids problems associated with third-party accessories, including compatibility-related crashes, abnormal power consumption, and damage to connected devices. Apple users can connect directly with confidence.
Dual Headphone Outputs and Two Gain Settings
More flexibility for different listening setups
Designed for the diverse needs of audiophiles, M18i Max comes with both a 3.5 mm single-ended output and a 4.4 mm fully balanced output. It works with conventional and balanced headphones, desktop Hi-Fi systems, and in-car audio systems.
Two manually selectable gain levels allow listeners to switch according to headphone impedance and personal preference. High and low gain accommodate different musical styles and equipment, giving users greater flexibility to tailor the experience.
High Definition Microphone with Noise Reduction
Clear voice calls
A flagship Infineon microphone works with Qualcomm cVc 8.0 high-definition call noise reduction to capture speech clearly from up to two meters away and effectively suppress surrounding noise. Everyday calls and online meetings benefit from transparent, clean vocals, resolving the poor call quality often encountered with portable DAC and headphone amplifiers.
Connections for Professional Equipment
For audiophile listening and professional work
Using 3.5 mm-to-RCA or 4.4 mm-to-XLR cables, M18i Max connects easily to powered speakers and professional studio equipment. It supports professional monitoring, reference listening during arranging, and on-site listening wherever you work, serving both audiophile enjoyment and professional applications.
Questyle M18i Max redefines the quality standard for flagship portable DAC and headphone amplifiers. It is an ideal choice for upgrading premium in-ear monitors, accompanying audiophiles on the move, and providing mobile monitoring for professional musicians.
