The Classy Questyle CMA 400i Headphone Amp – Review

Headphone Amp Review

A high-quality headphone amp with multiple different functions for under $1000 might be hard to come by. You might already own an amp, but are ready to upgrade to a more versatile model. The Questyle CMA400i is the latest amplifier from Questyle Audio Engineering, and it aims to create a gold standard in reference audio headphone systems. Does Questyle succeed in creating a superb reference system? The CMA400i goes for $799, which could set you back as a first purchase, but if you’re looking to settle down for something special, then the CMA400i might be what you’re looking for.

Headphone Amp box contents

What You Get 

The CMA400i comes in a large box that includes several key items. My unit only came with the bare necessities, the amplifier itself, and a 17W power cable. I would have liked to see the CMA400i include a USB-C cable for PC use, and it’s quite confusing why it doesn’t. The CMA400i has a ton of output options that it doesn’t supply the proper cables for, mostly the ones facing the rear of the device, as the ones facing the front are all headphone connectors. 

Headphone Amp Chassis

Build Quality

The CMA400i looks like a beast of an audio system. It screams high-quality with its classy presentation and design. The CMA400i looks like it could easily be a thousand dollar amp with just how sleek it looks. The cassis has an all-black design with a matte finish. It’s kept together by visible bolts that hold down the CNC aluminum shell, creating a hefty but durable composition, like you could run your car over it and the amp would still work fine ( warning: do not actually run the CMA400i over with your car). The device weighs about 2.4kg which is a considerable amount of density, but I found the device to be a lot lighter than it looks. Overall this is a professional, quality build that should sustain a large lifecycle. 

Headphone Amp volume dial


The front plate of the device houses several key inputs and interfaces. The on/off switch lies on the very right of the plate, sitting next to the CMA400i light indicators, and function switches. Switching between AMP and DAC was seamless and immediately responsive, with no delay whatsoever. There also lays an input button to jump between USB, OPT, and COX 1 or 2. Also included on the faceplate is your 2.5 balanced, and quarter-inch unbalanced headphone jacks, as well as a 4 pin balanced XLR input. Lastly, there’s the volume dial, which super smooth and responsive. The dial has specific areas of loudness, marked by white dots. I never had to crank them past the middle, as the CMA400i does the job right. 

The rear plate houses some more complex outputs as well. I mainly used the CMAs’ USB type B connector for listening straight into my PC. There’s also an opt, and 2 cox inputs for digital connection as well. For outboard use, the CMA400i also gives you an S/PDIF out, RCA, and male stereo outs for line-level connection to a possible pair of speakers or monitors. The CMA400i offers a ton of options for digital outboard gear connection, however, if you’re more of an analog listener, you might be disappointed. 

Headphone amp outputs


Getting the right listening experience is important to Questyle, and they’ve made the CMA 400i with balance and power in mind. Using different outputs and connections will differ in total voltage and impedance. The CMA 400i shares an impedance of 32 Ohms in both its balanced and unbalanced outputs, and can collectively reach a max power of 300 Ohms, but limited-use is recommended for safer listening. It will also give you the most reliable signal, so if you’re using the CMA400i for reference use, this seems to be the intended power setting. 

Headphone amp functions


There isn’t much to be said about the soundstage of the CMA 400i. Depending on what you’re listening to, it could feel spectacular, or flat. Accuracy is mainly what this amp is going for, but I felt wafts of extra space, and subtle layers to tracks that’s hard to experience otherwise. I tried out the AEON Ether Flow with the Questyle and put on the album “Anyo” by Tim Hecker and the amount of focused separation and air between instruments was almost maddening. Timpani sections were given room to pan through your headspace, as strings were plucked from a distance while still being incredibly present. There’s just this wonderful amount of headroom, that makes listening to all types of tracks dynamic and versatile.

Low End

The lows sat mostly at the bottom of the mixes I tested. Low mids had a larger presence, but the CMA 400i likes to keep things relatively smooth and balanced. So the bass doesn’t extend in any way, but the CMA 400i still presents a clean and eloquent timbre that should satisfy the more subtle low-end genres. Punchy bass smooths out and have more buttery textures while keeping low mids separate in the stage. This is not an amp for bass heads, but if you want to be analytical about your lows, you’ll enjoy the timbre of these bands.


Balanced, crisp, and dynamically consistent, these mids come in with clarity and accuracy. Instrumentations have great detail, especially in acoustical performances. String plucks and fret slides become more present with the CMA 400i making for an intimate folk track or a breathy orchestral performance that could add an extra amount of depth to a film score, like all the leitmotifs, other nuances could be pointed out easier. Vocals also sound immaculate, like they came straight from the studio, to my eardrums. Male and female vocals alike are so crisp and given ample room to share the stage with other mid-range elements. 


No sibilance or harshness could be heard whatsoever on the CMA 400i. Like the mids, the highs present a crisp and accurate frequency response. The most perceivable dip is in the highs, but it’s only a small amount, as presences like floor noise are still audible, which can add a sense of greater space to tracks. Some cymbal crashes also come out super crisp and articulate. It was perfect for listening to the new Killers album, which consists of a lot of shoegaze ambiances that became more pleasurable when trying out the CMA 400i.              


The Questyle CMA 400i is a classy and sharp headphone amp, with a lot of versatility at an affordable price for an amp of this quality. That’s really all there is to say about it, the CMA 400i is a really outstanding product perfectly suited for the audiophile looking for a great desk piece for their setup. 

Pros and Cons

Pros: Great build, separation, reference sound

Cons: No 3.5mm jack, not suitable for analog

Questyle CMA400i available at Audio 46

MAJORHIFI may get a commission from retail offers.

Compare the ranking of various headphones, earbuds and in-ear monitors using our tools.

Discuss this, and much more, over on our forum.

MAJORHIFI may receive commissions from retail offers.
Previous article64 Audio Nio IEM Review
Next articleCrafted By The Gods – Kinera Baldr IEM Review
Alex S. is a sound designer and voice-over artist who has worked in film, commercials, and podcasts. He loves horror movies and emo music.