Questyle M15i

Preface

I purchased my M15i with my own money from Amazon, all thoughts and opinions are my own.

The M15i was put on my radar because I was in the market for a nice DAC/AMP for my IEMs and headphones and I had been using Questyle’s cheaper M12i for a while. I kept them in mind for a while before eventually pulling the trigger.

Overview

Initial thoughts

I will break everything down later on.

Very easy to use, just plug it in and start playing music right off it. The 2 red LED lights turn right on indicating that it is on and working, along with what gain mode you're in (low-high) and the gain switch causes no pops or breaks in sound when flipped while audio is playing. The audio has a natural, uncompressed quality that sounds great, with no artifacts or noticeable issues. The part I like a lot about its sound is the treble, on a lot of IEMs it seems to add nice detail to the upper treble.

Unboxing

• Questyle M15i

• USB-C - USB-C cable

• USB-C female to USB-A male adaptor

• User manual

• Specs sheet

The no-nonsense package includes everything you need to use it happily and does not need any aftermarket accessories. Everything is well-built, and the packaging has a very good design and typography for those who appreciate marketing design. No complaints whatsoever.

Sound

As I mentioned before, the sound is very clean and just very good. The bass stays tight and clear without bloating, getting too soft, or becoming smoothed over, the mids just sound right, and the treble is affected in a very pleasing way. The upper treble region gets a little extra spice and detail but doesn't become any brighter or harsh, sometimes it even helps smooth peaky treble. 

One downside is sometimes I’ll hear a digital buzzing like once every one or two hours, messing with cable connections fixes it usually, also usually happens a bit after plugging in an IEM.

Headphone and IEM pairings

Nightjar Singularity

This is the IEM that benefits the most from the M15i. The Singularity can sometimes be perceived as slightly dark or veiled in the treble region, which sometimes is an issue when I want more detail out of my music. The M15i kind of opens up the treble and adds the detail I miss, it also seems to add a bit more texture to the treble, plucks on guitars, and breaths in voices become a bit more tactile and alive. 

The Singularity is an IEM that is very well known for its top-tier bass performance which can be very much affected by the source it is being run off of. On my other main source which I use on the go, the FiiO BTR17, while good, it is a bit lacking when compared to the M15i. The bass still slams and rumbles on the BTR17 but when I switch from one to the other after using one for a while, I can really feel the difference in the bass, on the M15i, it just feels more controlled, while on the BTR17, it can sound a little soft and smooth. The same goes for my Schiit Magni Unity. 

7th Acoustics Supernova

The Supernova tends to be quite easy to drive and make sound good, but it becomes a little tricky with sources when it comes to the bass. I generally don’t believe in “BA bass” but the Supernova’s bass is done by dual BA drivers and on a lower-quality source, that fact becomes more apparent. On the M15i, the Supernova’s bass is very tight and punchy, on my BTR17, the bass is also good but it lacks a little bit of impact that the M15i has.

The Supernova is also a brighter IEM with amazingly smooth treble but can get harsh on sources that might affect the treble, the M15i doesn’t give it the upper treble zing that I get on the Singularity and still keeps it very smooth.

Symphonium Crimson

The Crimsons showed me the biggest example of smoothing harsh treble, when I had the Crimsons on hand, I needed EQ to bear the upper treble on them but when I used them on the M15i instead of the BTR17, the treble seemed a bit smoother and more bearable without EQ

Sennheiser X Drop HD6XX

I am generally more used to IEMs and hearing sound differences on them so I don’t hear many major effects the M15i has on the 6XX. The main thing to appreciate about the M15i with the 6XX is that it can easily power them to well above comfortable listening levels. Before getting my M15i, the best source for the 6XX was my Schiit Magni Unity, but when it comes to sound, the M15i edges out the Magni. The 6XX seems to come a bit more alive and sounds a tad less sterile next to the Magni.