Skip to content
Available for pre-order. Available at the end of June.
Top-class portable music player
The SP4000 from Astell&Kern is a milestone in high-end digital audio reproduction. Thanks to its innovative Octa-Audio circuit architecture, the SP4000 achieves unprecedented sound precision and clarity.
Signal processing with four sophisticated AK4191 digital processors and four AK4499EX DACs enables precise signal transmission with drastically reduced noise levels. ESA (Enhanced Signal Alignment) technology ensures flawless frequency coherence, reproducing even the finest nuances down to the smallest detail. High Driving Mode helps the SP4000 deliver powerful and stable output, creating a soundstage that impresses with both its dynamic range and richness of detail.
The SP4000 is the first Astell&Kern player with a full-featured Android operating system. Any app, such as Tidal, Qobuz, Spotify, or Apple Music, can be installed and used quickly and easily. The ultra-low-noise LDO circuit reduces noise levels by up to 97 percent compared to previous models. The any-layer HDI PCB technology and a 99.9 percent pure copper shield ensure maximum signal purity and reduce electromagnetic interference.
The elegant 6-inch display with 2K resolution and the new 4.5th generation user interface combine functionality and design. The polished 904L stainless steel case and PVD-coated ceramic back combine technological perfection and refinement. A custom leather case made of the finest calfskin by Perlinger completes the package.
The SP4000 supports high-resolution PCM up to 32-bit/768 kHz and DSD512, and offers a wide range of applications with 3.5 mm and 4.4 mm headphone outputs and Bluetooth. With a playback time of up to 10 hours and 256 GB of internal storage, expandable by up to 1.5 TB via microSD, the SP4000 is the ultimate choice for audiophiles.
SP4000 Highlights
- Improved signal processing with Octa-Audio circuit design
- High drive mode for first-class sound quality
- Proprietary Enhanced Signal Alignment (ESA) technology minimizes group delays
- Ultra-low noise LDO regulator for first-class noise reduction
- Advanced Digital Audio Remaster (DAR) technology
- Full support for Android operating system
- New Generation 4.5 user interface
Connections
- 3.5 mm unbalanced headphone output/optical output
- Balanced 4.4 mm headphone output (supports 5-pin connectors only).
- USB-C input (for charging the battery and transferring data from a PC/Mac).
- WiFi 2.4/5GHz
- Bluetooth V5.0
Specifications
The SP4000 is Astell&Kern's first device to fully support the Android operating system. Any app, such as Tidal, Qobuz, Spotify, or Apple Music, can be installed and used quickly and easily. The SP4000 not only delivers flagship-level audio quality but also offers exceptional convenience, making it a sophisticated digital audio player.
The Octa-Audio circuit architecture offers improved signal processing capabilities.Through continuous research and innovation in circuit technology, Astell&Kern has succeeded in developing a true quad DAC with the SP4000—a feat previously considered impossible due to noise and other issues—and thus achieving an impressive signal-to-noise ratio.
The High Driving mode enables precise reproduction of the finest sound details, so you can enjoy your music even more clearly and intensely.
ESA (Enhanced Signal Alignment) technology aligns frequency signals so they arrive more evenly, minimizes frequency distortion, and significantly improves sound clarity and purity.
The power supply's LDO (Low Dropout) regulator reduces unwanted noise by up to 97% compared to previous models, resulting in a particularly clean and pure sound.
Any-Layer HDI (High-Density Interconnect) circuit board technology enables the precise design of complex circuits in the smallest possible space. It minimizes signal loss and delivers even finer and more detailed sound.
The 99.9% pure copper shielding prevents noise and electromagnetic interference, ensuring the sound is clearer and sharper than ever before.
Astell&Kern's DAR (Digital Audio Remaster) technology helps create an even more natural and refined sound. Instead of sending the audio file directly to the DAR engine, the SP4000 first uses the VSE (Virtual Sound Extender) to virtually restore lost harmonics in the first stage and enhance the sound quality. Then, in the second stage, the enhanced DAR engine performs oversampling with greater accuracy and completeness. Thanks to this two-stage approach, you'll hear deeper and more penetrating sound that's closer to the original recording than ever before.
The SP4000's user interface has been updated to offer even more features and a more immersive experience. The SP4000 captivates both visually and haptically with its sophisticated and modern design.
The SP4000 comes with a premium leather case crafted from calfskin by Perlinger, the world-renowned German leather house. Following an aniline dyeing process, Perlinger's proprietary pigments are added to achieve a deep, radiant color. An advanced anti-aging treatment ensures this radiant color lasts for a long time, completing the SP4000 with a leather case that embodies lasting beauty, durability, and luxury.
Improved signal processing capabilities with Octa-Audio circuit architecture
In the SP3000, the structure for digital and analog signal processing was separated in a 1:2 ratio. In the SP4000, it was further developed into a 1:1 architecture.
This new structure, which combines an AK4191 digital processor with an AK4499EX DAC, enables precise transmission of digital signals to a single DAC without the need to distribute noise, enabling improved signal separation and processing.
Through continuous research and innovation in circuit technology, the SP4000 has successfully implemented a true quad DAC—a feat previously considered impossible due to noise and other issues. This enables the SP4000 to achieve an impressive SNR (signal-to-noise ratio) of 131 dB, which is in no way inferior to the independent dual audio circuitry of its predecessor.
Technical details
- 6-inch touchscreen with 2K resolution (2160x1080).
- Case material: 904L stainless steel
- CPU: Octa-Core
- DAC: 4x AKM4191 + 4x AKM4499EX (Real Quad DAC).
- Decoding: up to 32 bit/768 kHz bit-by-bit playback.
- Bluetooth V5.0 (A2DP, AVRCP, aptX Adaptive, LDAC)
- WiFi 802.11 a/b/g/n/ac (2.4/5GHz)
- Supported audio formats: WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, DSF.
- Sampling rates:
PCM: 8kHz ~ 768kHz (8/16/24/32 bits per sample).
Native DSD: DSD64 (1 bit 2.8MHz), stereo/DSD128 (1 bit 5.6MHz), stereo/DSD256 (1 bit 11.2MHz), stereo/DSD512 (1 bit 22.4MHz), stereo. - Output level: Asymmetrical 4.1 Vrms/Symmetrical 8.2 Vrms (no load).
- Frequency range:
Asymmetrical: ±0.006dB - 20Hz ~ 20kHz.
Symmetrical: ±0.006dB - 20 Hz ~ 20 kHz
Unbalanced: ±0.06dB - 20 Hz ~ 70 kHz
Symmetrical: ±0.06dB - 20 Hz ~ 70 kHz - SNR: Asymmetric 129 dB @ 1kHz/Symmetric 131dB @ 1kHz.
- Crosstalk: Asymmetrical -136dB @ 1kHz/Symmetrical -145dB @ 1kHz.
- THD+N : Asymmetric 0.0005% @ 1kHz/Symmetric 0.0003% @ 1kHz.
- Output impedance: Asymmetrical 3.5 mm 0.7 Ohm/Symmetrical 4.4 mm 1.7 Ohm
- Clock Jitter: 25pS (Typ)
- Reference clock jitter: 200 femtoseconds
- Internal memory: 256 GB (NAND).
- microSD card slot for memory expansion (max. 1.5 TB).
- Battery: 6780mAh 3.8V Li-Polymer.
- Battery life: approx. 10 hours (standard: FLAC, 16 bit, 44.1kHz, Vol. 80, LCD Off, Low Gain).
- Charging time: approx. 4 hours (QC3.0 Charging).
- Dimensions: 85 x 149.8 x 19.5 mm.
- Weight: 615 grams.
Scope of delivery
- Astell&Kern SP4000
- Elegant case made of calf leather from the German tannery Perlinger.
- USB cable (USB-C to USB-A)
- Screen protector
- Quick start guide (German, French, English)
- Manual stored on the player in PDF format (German, French, English)
