If you love audio and you love your phone, you'll know that there's usually a compromise involved: even the best wireless headphones aren't quite as good as the best wired ones, and if you're just using your phone's output then you're not getting the same stellar sound you'd get from a dedicated DAC (Digital to Audio Converter). Enter audiophile brand Astell&Kern, whose new HC4 headphone amp and external DAC promises a big audio upgrade without a big price tag. It's designed to drive wired headphones and in-ear monitors without adding bulk, weight and too much expense to your portable audio setup.
The new AK HC4 is the successor to the firm's HC3, which we like a lot: in our Astell&Kern HC3 review we praised its ability to upgrade the sound of your laptop, tablet or phone. It's a genuinely great audio upgrade and the new version is better still.
What's new in the Astell&Kern HC4?
The big news here is that the HC4 has a brand new DAC, the AK4493S, for even better sound quality: that's usually reserved for the brand's much more expensive digital audio players. The DAC also has a feature called Digital Audio Remaster, an upsampling feature for getting "delicate, analogue-like sound" from your library and streaming services.
In terms of compatibility the HC4 has UAC 2.0 audio plus UAC 1.0 for older devices such as gaming handhelds. There are interchangeable USB-C and Lightning connectors for widespread compatibility with phones, tablets, computers and handhelds, and there is a choice of 3.5mm and balanced 4.4mm outputs for your high-spec headphones.
The addition of a balanced output addresses one of the big downsides of the outgoing model, which only had unbalanced output. But we haven't had the opportunity to test this model yet so we don't know whether A&K has also solved the Android compatibility issues: we found the HC3 was hit and miss with a Nothing Phone (1) so you may want to try before you buy if you're an Android owner.
As you can see from the photo it's a typical A&K design with a futuristic polygonal shape, and it's small enough to fit easily in your pocket or bag. It's on sale now for £219; the US price is $220, it's $399 in Australia and €249 in Europe.