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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Posted in: Hi-Fi
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