Astell & Kern AK HC4 vs Questyle M15 Comparison Review

Here are two impressive DAC/amp dongles for those who want hi-res sound on-the-go. The Questyle M15 has been a best-seller this year, while the Astell & Kern HC4 is completely new to the scene. Both models sell at around the same price point, though their sound signatures are quite distinct in flavor. Which DAC/amp dongle is the better performer? And which sound profile will best suit your tase?

Build and Design

It might be hard to pick which DAC aesthetic is most appealing. The M15 strikes a nice balance between elegance and fun, with a transparent glass panel that reveals intricate design details. Contrastingly, Astell & Kern’s HC4 sports a sleeker, more minimalist look, with its trademark bold and edgy vibe. The HC4 may be slightly more solid than the M15, which is fundamentally more fragile given its glass casing in the front. 

As for the more basic design attributes, both DAC dongles are about the same size, with Questyle being just slightly smaller. And both DACs weigh about the same.

Inputs and Outputs

Both DACs feature a USB Type-C input and 3.5mm/4.4mm headphone outputs. However, while the HC4 comes with both, a USB-C and a Lightning cable, the M15 doesn’t provide any options for iOS devices. (Of course, you can easily buy this cable online.)

Controls and Features

With respect to controls, the MC4 has a volume button but no gain switch, while the M15 has a gain switch but no volume dial. Personally, I value volume control over a gain switch, but if you’re using particularly sensitive IEMs, the gain feature may be useful. Finally, the AK HC4 also has the added feature of a DAR switch, which upsamples your sound files, aiming to achieve a similar quality to DSD.

Hi-Res Support

Both, the Questyle M15 and AK HC4 can play sample rates up to 32 bit / 384 kHz. But the M15 has the added advantage of MQA support, while the HC4 leaves Tidal users hanging. Finally, both, the M15 and AK HC4 have tiny LED lights that indicate the kind of file being played.

Power

Both DACs do a great job at powering both sensitive IEMs and over-ear cans that are harder to drive, like the Beyerdynamic DT 1770, which has an impedance at 250 Ohms. And when the M15 at high gain, both models provide an equal amount of headroom.

Sound Impressions

Let’s start with the fact that these dongles are virtually equal in skill. But perhaps the most apparent difference between these two dongles lies in the soundstage. The M15 fosters a cleaner mix, ensuring an accurate representation of the stereo field. But nothing seems exaggerated, even though the width is still impressive. On the other hand, the HC4 sometimes feels more holographic and less intimate. The space it delivers feels broader and deeper, exceeding modest imaging tweaks. It also seems to better enhance the resolution of sound elements that are placed at distance. And overall, the added color and robustness of the HC4 makes for a more dynamic soundstage. Still, which is the more natural presentation? Probably the M15. 

The same difference applies to the rest of the sound signature, with the M15 remaining pretty honest to the source, while the HC4 injects extra boldness into to the mix, especially in the mids and lower frequencies.

Overall, if you’re looking for the most neutral profile, the M15 will deliver your sound with minimal manipulation. However, if you’re thirsty for a more vibrant soundstage and a more colorful and muscular flavor to your current sound signature, the HC4 is probably the preferable DAC/amp.

Summary

I think the choice comes down to taste and intended application because both DACs sound fantastic. If you want your sound signature to be significantly bigger and more energetic, go for the HC4. But if you’re looking for the most accurate and neutral profile, the M15 is hard to beat. As for the design attributes, the HC4’s volume buttons give it the upper hand in my books. But if you can’t do without MQA files, the M15 will have to be your choice. Still, especially given their similar price points, you can rest assured that both models will be an equally worthy upgrade to your sound.

You can buy the Astell & Kern AK HC4 at Audio 46.

You can buy the Questyle M15 at Audio 46.