Questyle’s M18i mobile headphone amp, which just debuted at CES 2025, might look like a typical dongle-style DAC/amp — it actually bears a strong resemblance to the company’s M15 DAC/amp — but it’s far more sophisticated.
The $349 device can connect to your phone’s USB-C port and translate any PCM signal up to 32-bit/384kHz (or native DSD up to 256) into powerful analog audio through two different headphone jacks (3.5mm unbalanced/4.4mm balanced). It’s also a Bluetooth receiver that’s absolutely packed with hi-fi codecs including LDAC, LC3 (via LE Audio), and the full suite of Qualcomm Snapdragon Sound aptX codecs (aptX Adaptive, HD, and Lossless). And it can receive USB Audio while charging thanks to two dedicated USB-C ports.
Better yet, it has its own rechargeable battery, good for a claimed 4 hours of playtime, and a high-quality internal microphone so you can take calls, even when using an audiophile-grade set of wired headphones or in-ear monitors.
But my favorite part is the built-in OLED screen, which lets you see exactly what’s going on, including the current bit depth and sample rates, the codec in use, volume level (there are 60 to choose from), and battery life. It also gives you instant confirmation of what the DAC is receiving from its source.
Speaking of sources, there’s a convenient three-way switch on the side of the M18i that lets you seamlessly swap between mobile, PC, and Bluetooth modes, plus a multifunction button that controls pairing and gain levels.
On the inside, the M18i benefits from a dual ESS ES9219Q DAC — one for each headphone output. The output signals are then processed through both a preamp and an amplification stage (powered by two patented quad-core Current Mode Amplifier SiP modules) before finally reaching the jacks. Questyle says this architecture results in a minuscule 0.0002% distortion when under 300 ohms of impedance, a noise floor lower than -130 decibels, and a 1.5 amp/28 milliwatts output.
Since you’ll probably want to use the M18i in a variety of situations, there’s also an available $30 case that comes with an integrated clip.
Both the M18i and its matching case should be available on Questyle’s site, Amazon, and various other retailers starting today, January 6.
