For audiophiles, dedicated headphone amps are a key component in their personal audio arsenal, one that lets them get the most out of their preferred wired cans. But Astell&Kern (A&K) clearly believes we haven’t been expecting enough from these devices, so it has launched the $2,199 A&K Acro CA1000, a so-called “carriable” headphone amp that packs its own internal rechargeable battery as well as a full-featured, hi-res audio digital audio player. The pricey but capable hybrid gadget will be available January 24 at authorized Astell&Kern dealers in the U.S. and Canada.
The Acro CA1000 ticks an enormous number of boxes for folks who want maximum flexibility for controlling and enjoying digital music. It has two sizes of balanced outputs (2.5 and 4.4mm) and two sizes of unbalanced jacks (3.5 and 6.35mm), which should work with a majority of both general use headphones as well as audiophile-grade models. The built-in digital audio player — accessed via a multi-angle touchscreen — pumps data through a quad set of ES9068AS digital-to-analog converters (DACs), and they’ll handily crunch any file you throw at them, including WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, DSF, plus there’s full rendering support for the MQA format and bit-perfect playback of up to 32-bit/384kHz PCM and native DSD512 (22.4MHz) tracks.
As with A&K’s other hi-res digital audio players like the SR25, you can stream from a wide variety of streaming music services via Wi-Fi, including Apple Music, Amazon Music, Spotify, Tidal, SoundCloud, Qobuz, SiriusXM, Tune-In, myTuner, Bandcamp, and Deezer. Given that Apple Music, Amazon Music, Tidal, Deezer, and Qobuz all offer lossless and hi-res tracks, the Acro should let you get the most out of these services.
Prefer to listen to your own music collection? You can load files onto the Acro CA1000’s internal 256GB of memory, read them from microSD cards up to 1TB in size, or browse your network-stored music via DLNA. It can also (with an upcoming firmware update) be used as a Roon endpoint.
That internal battery is good for about 10.5 hours of playback in low-gain mode, but you can also keep the unit plugged in via a USB-C charging cable and use it as a hard-wired device. Speaking of gain, A&K claims that the amp supports four levels of gain settings (accessible from the touchscreen) so you’ll be able to drive even high-impedance headphones without any loss of sound quality. The term “carriable” is appropriate: Calling it portable would be a bit of an over-promise, but given its relatively small size — it’s small enough to be held in one hand — it’s way more portable than typical dedicated headphone amps. We’d also like to take a moment to acknowledge A&K’s trademark oversized volume knob, which looks like it’s been beautifully machined, complete with a knurled texture for grip.
But wait, there’s more: Thanks to generous compliment of source inputs (RCA analog, optical, coaxial, and USB-C) and outputs (RCA analog) — each of which can be configured via the touchscreen — it can be used with all of your existing audio gear as either a source or a receiver. And it’s not just for wired audio. It’s equipped with Bluetooth 5.1 and can work in both directions, acting as a BT source for wireless headphones and speakers, or as a high-end BT receiver. Under ideal conditions, 24-bit wireless audio is possible with support for both Sony’s LDAC and Qualcomm’s aptX HD codecs.
And finally, the Acro offers support for a feature called Crossfeed. According to A&K, headphone listeners can suffer from ear fatigue over longer listening sessions because of the separation that exists between left and right channels. Crossfeed aims to reduce that sense of fatigue by creating a new mix that more accurately reproduces the effect of listening to full-sized speakers. The Crossfeed settings are fully configurable using the touch interface.
The A&K Acro CA1000 might be an expensive toy, but its unique combination of features could justify the investment if you belong to the group of folks who, perhaps without even knowing it, want exactly what it offers.
