Astell&Kern has officially announced its latest flagship portable audio player: the A&Ultima SP4000. Set to make its first appearance at this year’s High End Munich Show (15-18 May), the SP4000 arrives with a long list of updates aimed at today’s streaming-focused listeners. It’s the follow-up to the well-regarded SP3000 and brings changes across both hardware and software.

Perhaps the most noticeable change is that the SP4000 now runs a full version of Android. Unlike earlier A&K players that used a limited or heavily modified OS, this model lets users install apps directly from the Google Play Store. So, if you want to use Spotify, TIDAL, Qobuz, or even YouTube Music, you can do that natively—no sideloading or special workarounds required.

To make sure this doesn’t compromise sound quality, Astell&Kern has included its own Direct Path and ADP (Advanced Digital Path) systems. These are designed to bypass Android’s built-in resampling process, which can otherwise reduce audio fidelity. With these in place, the SP4000 supports bit-perfect playback, even when you’re streaming from third-party apps.

Under the hood, the SP4000 gets a major overhaul with what A&K calls its “Octa” circuit architecture. That includes a pairing of the AK4191 digital processor with a single AK4499EX DAC. That 1:1 configuration is a departure from the previous 1:2 setup seen in past models and is designed to reduce noise and improve signal separation. In theory, this means cleaner, more accurate sound.

There’s also a new “High Driving Mode” that uses two OPAMPs in parallel. This setup boosts output power without raising the noise floor—something that should help when using more demanding headphones, especially in balanced mode. Astell&Kern has compared this to “four-wheel drive” for your music, offering more control and power without sacrificing detail.

The SP4000 also introduces several new features designed to clean up audio signals and improve timing. One of these is ESA (Enhanced Signal Alignment), which helps reduce group delay—a technical term for when different frequencies arrive at slightly different times. That can cause issues with stereo imaging or soundstage depth, so reducing that delay helps music feel more cohesive.

The player also uses a low dropout (LDO) regulator in the power circuit to stabilize voltage and suppress noise. These regulators are often found in medical and communications gear due to their reliability, and here they help bring down electrical noise by up to 97% compared to previous models.

In terms of build, the SP4000 leans heavily into premium materials. The body is made from 904L stainless steel—the same alloy used in high-end watches—paired with a PVD-coated ceramic back. It also comes with a custom leather case from German leather house Perlinger, made from shrunken calf hide for a soft, textured finish.

On the front, there’s a 6-inch touchscreen running version 4.5 of Astell&Kern’s user interface. You’ll still get the brand’s signature Crimson Theme, but the overall look is cleaner and more animated, with sliding album artwork and easier navigation baked in.

As you’d expect from a flagship model, the SP4000 supports a wide range of audio formats, including up to 32-bit/768kHz PCM and DSD512 files. Bluetooth support includes both aptX Adaptive and LDAC, so you can stream 24-bit audio wirelessly. There's also a BT Sink feature that lets you stream music from another Bluetooth device—like a phone—while still benefiting from the SP4000’s high-end processing.

For wired connections, you get USB-C for data and charging, USB digital audio output, and support for DLNA networking. It can even be used as a USB DAC for your computer. Storage includes 256GB of built-in memory, plus a microSD card slot that supports up to 1.5 TB.

Battery life is rated at around 10 hours of continuous playback. The player uses Qualcomm Quick Charge 3.0, and it takes about four hours to fully recharge via USB-C.

Astell&Kern hasn’t confirmed the price yet, but considering the previous SP3000 launched at $3,699, the SP4000 is likely to land in a similar range. It’s expected to go on sale this summer, shortly after its showcase in Munich.