Here is our review of the Questyle MEX.
Unlock the true potential of your headphones with the Questyle MEX, a next-generation mobile DAC and headphone amplifier designed for listeners who want genuine driving power without the bulk. Enjoy rich, detailed and natural sound powered by dual ESS ES9219Q DACs and Questyle’s patented SiP Current-Mode amplification, with support for up to PCM 384kHz/32-bit and Native DSD256.
Stay in control with the TTA Three-Tier Architecture and three gain levels that match everything from demanding 300Ω headphones to sensitive earphones. Experience faithful, untouched sound in PURE mode, or slide over to TUNE mode and shape your sound with presets and parametric EQ in the Questyle App.
With 3.5mm single-ended and 4.4mm balanced outputs, Apple MFi certification and support for iOS, Android, Windows and macOS, the MEX goes wherever you do. Enjoy a striking transparent design, a handy OLED display, physical buttons, DRE and DAC filter control, and ongoing app updates that will bring Q-Code tuning sharing in the future.
Features
- Dual ESS ES9219Q DACs in a dual-mono differential design.
- Four patented SiP Current-Mode amplifier groups drive 300Ω headphones.
- Supports PCM up to 384kHz/32-bit and Native DSD256.
- 3.5mm single-ended and 4.4mm balanced outputs, up to 4V @ 300Ω.
- PURE mode for original sound, TUNE mode for EQ and PEQ.
- Three gain levels, 64 volume steps and left/right balance.
- Choose DRE settings and DAC filters in the Questyle App.
- Apple MFi certified, works with iOS, Android, Windows and macOS.
- Built-in microphone and 3.5mm CTIA headset support for calls.
What’s in the box?
The box contains the MEX, a USB-C to USB-C Cable, a USB-A to USB-C Adapter, a Warranty Card and a User Manual.
A Closer Look
Final Thoughts
The MEX is small and lightweight and feels really well made, with a CNC-machined aluminium frame and a transparent window on the back that lets you see all of the circuitry inside – it really does look the part.
There is no battery to worry about, as the MEX is powered by whatever device you plug it into. Just connect it to your phone, tablet or computer using the supplied USB-C cable and you are ready to go. Don’t worry if your computer only has USB-A ports, as there is an adapter in the box too.
Setting the MEX up is really simple and quick and it worked straight away with everything I tried, and it is also Apple MFi certified so iPhone and iPad users are covered.
The OLED display on the front shows you the volume, gain, balance, DAC filter, sample rate and which mode you are in, so you can see everything at a glance. The physical buttons are easy to use and you get 64 volume steps, which makes finding the right listening level easy.
The sound quality is fantastic, with music coming through clearly and with plenty of detail no matter what type of music you are listening to. Thanks to the three gain levels it has more than enough power to drive 300Ω headphones, and it works just as well with sensitive earphones. If you have headphones with a 4.4mm balanced cable you can get even more out of them.
There are two distinct modes you can choose from using the slider on the side – PURE and TUNE – they both work really well and they are easy to switch between. PURE gives you the original sound with no fuss, while TUNE lets you get creative.
You can also use the Questyle App to pick EQ presets, create your own PEQ settings, and change the gain, DRE, DAC filters and balance – definitely take a look at it as it can really personalise the experience for you. Questyle has also promised future updates that will add Q-Code, letting you share and import tuning profiles with other users.
The Questyle MEX is due for release during December 2026 and expected to be priced around £170.
