Astell & Kern New Flagship SP4000 DAP Breaks Cover
Astell&Kern has lifted the curtain on its new flagship digital audio player, the A&ultima SP4000, a product the company describes as the culmination of three years of continuous innovation.
Officially launching next week at High End Munich 2025 at the iRiver stand (Hall 1, Booth D03), the SP4000 headlines a refreshed push from Astell&Kern into the bleeding edge of portable high-end audio, with two new in-ear monitors also set to debut at the show.
Replacing the SP3000 at the top of the A&ultima range, the SP4000 introduces a redesigned Octa Audio Circuit architecture, pairing one AK4191EQ digital modulator with a single AK4499EX DAC for each channel. This 1:1 signal processing path is a first for Astell&Kern, delivering what the company says is a true Quad-DAC configuration that improves signal purity by physically separating digital and analog processing. Added to this is High Driving Mode, which uses parallel op-amps for greater dynamic control, and ESA (Enhanced Signal Alignment) technology that reduces group delay distortion — all in the pursuit of ultra-precise, immersive playback.
The SP4000 also marks a turning point for Astell&Kern’s usability. It is the brand’s first DAP to run a full Android OS, allowing users to download streaming apps directly. Bit-perfect playback is preserved via Astell&Kern’s custom ADP (Astell&Kern Direct Path) engine. A new 4.5-generation GUI brings smoother visuals, redesigned interactions, and an LP-inspired interface animation, adding flair to function.
On the hardware front, the SP4000’s case is sculpted from 904L stainless steel — the same grade used in luxury watches — paired with a PVD-coated ceramic back and protected by a Perlinger Shrunken Calf leather case, sourced from the esteemed German tannery. A new ultra-low-noise LDO regulator, 99.9% copper shielding, and Any Layer HDI PCB technology further reinforce the SP4000’s attention to electrical isolation and thermal control.
Connectivity is extensive, with support for 32-bit/768kHz PCM, DSD512, LDAC, aptX Adaptive, Bluetooth DAC (BT Sink), USB DAC, USB-C fast charging, ReplayGain, DLNA, and microSD expansion up to 1.5TB. A 6-inch 2160x1080 touch display anchors the user experience, with around 10 hours of battery life and QC 3.0 fast charging.
Astell&Kern has also confirmed that the SP4000 will receive Roon Ready support following certification. It includes adjustable Crossfeed settings for headphone users seeking a more speaker-like presentation. In addition to the SP4000, the company will preview two new IEMs at the show:
Luna – An in-house design featuring a unipolar micro planar magnetic driver with a frequency range of 20Hz to 30kHz, paired with a premium Eletech hybrid cable using silver-coated OCC and copper OCC wiring.
XIO – A ten-driver collaboration with 64 Audio, including a true isobaric cone-to-magnet configuration for low distortion, housed in a polished 904L stainless steel shell with DLC (Diamond-Like Carbon) coating.
The A&ultima SP4000 is expected to be available globally from mid-2025, with pricing to be confirmed soon.
For more information visit Astell&Kern
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Jason Sexton
Joining StereoNET in 2025 as Deputy Editor, Australia & New Zealand, Jason’s decades of experience comes from a marketing, brand development, and communications background. More recently, a decade in specialist retail has armed him with the knowledge required to deliver the right information to a captive and curious audience.
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