The Questyle M15i is a portable high-fidelity headphone preamplifier that pushes the boundaries of audio quality on the go. As the successor to the popular M15, this new model brings notable improvements while retaining the features that made its predecessor a success.
At the heart of the M15i lies the ES9281AC digital-to-analog converter (DAC) from ESS Technology. This high-end chip supports impressive sampling rates of up to 32-bit/768 kHz in PCM and native DSD512. This marks a significant improvement over the original M15, which was limited to 32-bit/384 kHz and DSD256.
This extended processing capability allows the M15i to fully exploit the most demanding high-resolution audio files. Whether you’re listening to 24-bit/192 kHz studio masters or DSD recordings, the M15i reproduces every nuance with exceptional fidelity.
The ES9281AC DAC is renowned for its sound clarity, low noise level, and ability to reveal the finest details. Combined with Questyle’s expertise in audio circuit design, it forms the foundation of a truly high-level sound reproduction.
The M15i stands out with its proprietary amplification system called “Current Mode Amplification” (CMA). This patented technology by Questyle uses current-mode amplification instead of voltage-mode, enabling a very wide bandwidth and an extremely low distortion rate.
The M15i incorporates two CMA SiP (System-in-Package) modules, offering a total of four amplification stages. This configuration delivers generous output power while maintaining an incredibly low distortion level of 0.0003%.
In practical terms, this translates to a sound of great purity, free from coloration or harshness, even at high listening levels. Dynamics are preserved, and transients are reproduced with precision, giving the sound a striking liveliness and realism.
The M15i is designed to adapt to a wide range of headphones and earphones. It features two outputs: a classic 3.5 mm unbalanced jack and a 4.4 mm balanced Pentaconn jack. The latter offers increased output power and better channel separation for compatible headphones.
A gain switch allows you to adjust the output power based on the sensitivity of the headphones used. In low-gain mode, the M15i delivers 11.97 mW at 300 Ω on the 3.5 mm output. In high-gain mode, this power increases to 22.60 mW at 300 Ω on the 4.4 mm balanced output.
This flexibility enables the M15i to accommodate both sensitive in-ear monitors and power-hungry planar headphones. Whatever your equipment, you can fully enjoy the M15i’s capabilities.
One of the M15i’s strengths is its broad compatibility with various devices and operating systems. Apple MFi-certified, it works perfectly with iPhones and iPads without requiring an additional adapter.
For Android, the M15i is compatible with version 5.1 and later of the operating system. It also supports HarmonyOS, Huawei’s operating system.
On computers, the M15i works natively with macOS and Windows 10 (from version 18.3) without requiring driver installation. This extensive compatibility makes it an ideal companion for enjoying high-quality sound in any situation.
Despite its high performance, the M15i retains an ultra-compact format that easily fits in a pocket. Its CNC-machined aluminum casing provides robustness and elegance.
The top surface is covered with Kunlun glass, revealing the internal components. This original design is complemented by two LEDs indicating the gain level and the sampling rate of the processed signal.
All connectors and controls are thoughtfully arranged on the device’s edges for intuitive use. The M15i thus combines refined aesthetics with well-thought-out ergonomics.
The M15i features a TOREX power management system that optimizes energy consumption. This technology maintains high performance while minimizing the impact on the source device’s battery life.
Unlike some portable DACs equipped with internal batteries, the M15i draws its power directly from the connected device. This approach reduces the device’s size and weight while avoiding the hassle of recharging an additional battery.
Yes, the M15i is compatible with Android smartphones running version 5.1 or later of the operating system. Simply connect it via your phone’s USB-C port to start using it immediately.
Absolutely. The M15i is Apple MFi-certified, meaning it is natively recognized by iOS devices. You can connect it directly to your iPhone or iPad’s Lightning port without an additional adapter.
Yes, the M15i features a gain switch that allows you to adjust its output power. In low-gain mode, it is perfectly suited for sensitive in-ear monitors without risk of hiss or distortion.
The 3.5 mm output is a standard unbalanced output compatible with most headphones. The 4.4 mm output is a balanced output that offers increased power and better channel separation for compatible headphones.
No, the M15i works natively with Windows 10 (from version 18.3) and macOS without requiring additional driver installation. Simply plug it in to start enjoying it immediately.
No, the M15i does not have an internal battery. It draws power directly from the connected device. This reduces its size and weight while avoiding the hassle of recharging an additional battery.
Ronan
I’m amazed that such a small item can produce such sound, connected with a Mezzanine Audio Pro headset and my iPad, I’m impressed by the result
Comment from May 21, 2026 — Experience from April 30, 2026
Clemens
Ultra easy to use. Small enough to always take with you.
The sound is absolutely impressive. I am very satisfied and can only recommend buying it.
Very well suited for ASMR sounds.
Comment from May 13, 2026 — Experience from May 02, 2026
Jean Claude
DAC that I use both with my smartphone and my computer for headphone listening.
The improvement in musicality is notable, with great consistency across the different timbres.
Comment from March 31, 2026 — Experience from March 19, 2026
