The original Questyle M12 and M15 were two of our favorite dongle DACs of 2023. However, we just learned they’re being replaced by new Apple MFi Certified “i” models. Priced at $199 and $299 respectively, the M12i and M15i ensure support for iPhone/iPad and seamless integration into the Apple ecosystem.

Although the first generation models worked with iPhones, the new models should offer greater performance and potentially last longer since they meet Apple’s stringent requirements for external devices in terms of power consumption and compatibility.

In addition, Android versions 5.1 and above, Windows 10 version 18.3 and above (driver-free), HarmonyOS and Mac OS have all passed rigorous testing.

Ultimately, they’ll improve the sound quality from your phone with wired headphones. Each model does so with varying levels of power and performance depending on the headphone and IEMS on the other end.

Tip: Instead of the term “Dongle DAC”, Questyle calls them “Mobile Headphone Amplifiers with DAC” to more accurately describe their function.

Questyle M12i

Questyle M12i Dongle DAC
Questyle M12i

At $199, the M12i is smaller and simpler to use. It features Questyle’s unique Current Mode Amplification paired with the ESS flagship USB DAC chip. In addition, it features automatic impedance detection which reconfigures itself each time a new headphone is connected.

Upon detecting the insertion of headphones, the M12i instantly activates working mode, recognizing and configuring the corresponding gain for the connected headphones. When the gain light is illuminated, a single indicator represents low gain, suitable for low-impedance headphones, avoiding overdriving. Dual red indicators represent high gain, providing sufficient drive for high-impedance headphones. 

If M12i is connected as a mobile DAC to Hi-Fi systems, active speakers, etc., it will automatically switch to high-level output, providing sufficient support for Hi-Fi audio systems.

Where to buy: $199 $149 at Questyle

Questyle M15i

Questyle M15i Dongle DAC
Questyle M15i

At $299, the Questyle M15i offers an additional fully balanced 4.4mm input and greater power output, but opts for manual gain control instead of automatic. That sounds like a negative, but we believe advanced users will appreciate the M15i’s manual gain option.

More importantly, the M15i should sound the better of the two. It contains two groundbreaking “current mode” patent amplification SiP modules developed by Questyle Technology.

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Overall, it utilizes four current mode amplification engines for generating powerful and clear sound. Given that it operates in the current domain, the low impedance characteristics of the current-mode circuit result in a bandwidth of up to 1MHz and distortion as low as 0.0003%. The company says this development makes it possible to discern even the tiniest details when listening to music.

Where to buy: $299 $249 at Questyle

Questyle M15i Dongle DAC front and back
Questyle M15i

Should You Upgrade?

If you’re already a happy Questyle M12 and M15 owner, there are a few differences to consider. Both M12i and M15i drop support for MQA, but double D/A decoding up to 32-bit/768kHz PCM and DSD512 (from 32-bit/384kHz and DSD256). Of minor note, the status indicator lights are different on the new models.

Interestingly, all four models use the same ESS ES9281AC DAC.

Tip: Prior iPhone/iPad owners may require a Lightning to USB-C adapter (sold separately, e.g. Questyle LTC02 Lightning to Type-C adapter). All models include USB-C cables and USB-C to USB-A cables in the box.

M12i vs. M15i

M12i M15i
MSRP $199 $299
Outputs 3.5mm 3.5mm
4.4mm fully balanced
Gain Control Automatic Manual
CMA SiP Module Single Dual
CMA Engines 2 4
Decoding PCM768 / DSD512 PCM768 / DSD512
THD + N 0.0003% 0.0003%
Dimensions (HxWxD) 56.9 × 20.2 × 9.5 mm 61.91 × 27.9 × 12 mm

Which one should you buy?

Until we get the new models in for review, it’s too soon to say how they compare sonically to the previous generation. If you care about MQA, then get one of the older models, which are on sale at while supplies last.

Related reading: Find out about the latest Dongle DACs.