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Available on order approximately end of February.
The pinnacle of pure resonance - SP4000 Copper Limited Edition
The A&ultima SP4000 Copper Limited Edition is more than just a high-quality portable audio player. It is the result of Astell&Kern’s many years of experience in materials engineering, precision manufacturing, and refined analog sound design.
The SP4000 Copper is the brand’s definitive answer to a single question: How far can we go in the pursuit of ultimate sound? Copper is theoretically one of the ideal materials for audio applications but is among the most difficult materials to use in real products.
Its exceptional electrical conductivity and superior electromagnetic shielding minimize even the slightest signal loss, but its rapid oxidation and low surface stability make practical application extremely difficult.
In portable devices constantly exposed to temperature fluctuations and external influences, copper poses an even greater risk. Instead of avoiding this challenge, Astell&Kern faced it head-on and applied an advanced multi-layer coating process that requires a high level of technical know-how to ensure the long-term stability of 99.98% pure copper.
The exterior is never designed merely for the sake of design. High-purity copper is very susceptible to the slightest deformations during processing, yet the accumulated expertise of Astell&Kern enables precise control down to the finest tolerances. Through this process, the SP4000 Copper is realized not as a mass product but as a beautifully crafted high-end audio object.
Above all, the sound is the result of this tireless craftsmanship. Free from exaggerations or coloration, it conveys the texture and weight of the instruments, the tempo and breath of the performance, becoming an exceptionally refined expression of the original sound—enhanced by the natural properties of copper.
Deep, powerful bass, dense and clear mids, and naturally fading highs merge into a single, cohesive flow of sound that fully brings emotions to life through the audio. Beyond the "great sound," it offers an experience where the true value of the original recording is faithfully reproduced.
The SP4000 Copper Limited Edition embodies Astell&Kern’s unwavering commitment to pushing boundaries without compromise. The SP4000 Copper was designed for those who truly understand the essence of pure sound and sets new standards for what high-end audio can achieve.
Highlights
- Enhanced signal processing features with Octa-Audio circuit architecture
- Supports High Driving Mode for premium sound quality
- Minimizes group delays with proprietary ESA technology (Enhanced Signal Alignment)
- Ultra-low-noise LDO regulator for premium noise suppression
- Precise sound thanks to Any Layer Type PCB
- Equipped with a shielding made of 99.9% pure copper
- First device from Astell&Kern to support the full Android operating system
- First device from Astell&Kern with advanced DAR technology
- Features a 4.5 generation user interface that combines functionality and emotional design
Reviews
"The Astell&Kern SP4000 probably is the best DAP on the market right now from a technical point of view. The only downsides this time are the heavy price tag, the large dimensions and the heavy weight."
Astell&Kern SP4000 Review - Headfonia
"You have to be realistic, because at this flagship level, you can’t reinvent the wheel. But A&K managed to come up with a very focused, impressive finetuning where I hear notes in SP4k to have more weight and more solid body, while remaining very detailed and natural. The technical performance has improved with the sound being fuller, tighter, having a blacker background, and more holographic imaging under the new Advanced DAR implementation."
Astell & Kern A&K SP4000 – Twister6 Reviews
Top-class portable music player
The SP4000 from Astell&Kern is a milestone in digital high-end audio playback. Thanks to its innovative Octa-Audio circuit architecture, the SP4000 achieves unprecedented precision and clarity of the sound image.
Signal processing with four advanced AK4191 digital processors and four AK4499EX DACs enables precise signal transmission with drastically reduced noise levels. ESA technology (Enhanced Signal Alignment) ensures flawless frequency coherence, so even the finest nuances are reproduced in the smallest detail. The High Driving mode helps the SP4000 deliver powerful and stable output performance and creates a soundstage that impresses with both its dynamics and detail richness.
The SP4000 is the first Astell&Kern player with a full Android operating system. Any app such as Tidal, Qobuz, Spotify, or Apple Music can be easily and quickly installed and used. The ultra-low-noise LDO regulation reduces noise levels by up to 97 percent compared to previous models. The Any-Layer technology HDI-PCB and a shield made of 99.9 percent pure copper ensure maximum signal purity and reduce electromagnetic interference.
The elegant 6-inch display with 2K resolution and the new Generation 4.5 user interface combine functionality and design. The polished 904L stainless steel body and the PVD-coated ceramic back unite technological perfection and sophistication. A custom leather case made from the finest Perlinger calf leather completes the package.
The SP4000 supports high-resolution PCM up to 32 bit/768 kHz as well as DSD512 and offers versatile options with 3.5 mm and 4.4 mm headphone outputs plus Bluetooth. With up to 10 hours of playback time and 256 GB internal storage expandable via microSD up to 1.5 TB, the SP4000 is the ultimate choice for audiophile music lovers.
SP4000 Highlights
- Enhanced signal processing with Octa-Audio circuit design
- High drive mode for premium sound quality
- Proprietary Enhanced Signal Alignment (ESA) technology minimizes group delays
- Ultra-low-noise LDO regulator for premium noise suppression
- 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 4.4mm headphone output (supports only 5-pin connectors).
- USB-C input (for charging the battery and data transfer 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 easily and quickly installed and used. 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 enhanced signal processing capabilities. Through continuous research and innovation in circuit technology, Astell&Kern has succeeded with the SP4000 in developing a true quad DAC - a feat previously considered impossible due to noise and other issues - achieving an impressive signal-to-noise ratio.
The High Driving mode enables precise reproduction of the finest sound details, allowing you to enjoy your music even more clearly and intensely.
The ESA technology (Enhanced Signal Alignment) aligns frequency signals to arrive more evenly, minimizes frequency distortion, and significantly improves the clarity and purity of the sound.
The LDO regulator (Low Dropout) of the power supply reduces unwanted noise by up to 97% compared to previous models, resulting in an exceptionally clean and pure sound.
The Any Layer HDI (High-Density Interconnect) PCB technology enables the precise design of complex circuits in the smallest space. It minimizes signal loss and delivers an even finer and more detailed sound.
The shielding made of 99.9% pure copper prevents noise and electromagnetic interference, ensuring that the sound is clearer and sharper than ever before.
Astell&Kern's DAR technology (Digital Audio Remaster) helps produce 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 overtones in the first phase and improve sound quality. Then, in the second phase, the advanced DAR engine performs oversampling with greater accuracy and completeness. Thanks to this two-step approach, you hear a deeper and more penetrating sound that is closer to the original recording than ever before.
The user interface of the SP4000 has been updated to offer even more features and an emotional experience. The SP4000 captivates both visually and tactilely with its refined and modern design.
The SP4000 comes with a high-quality leather case crafted from calf leather by Perlinger, the world-renowned German leather house. After an aniline dyeing process, Perlinger's own pigments are added to achieve a deep, radiant color. The advanced anti-aging treatment ensures that this radiant color lasts a long time and completes 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 has been developed into a 1:1 architecture.
This new structure, where a digital processor AK4191 is paired with a DAC AK4499EX, enables precise transmission of digital signals to a single DAC without distributing noise, allowing improved signal separation and processing.
Through continuous research and innovation in circuit technology, it has been possible to implement a true Quad DAC in the SP4000 – a feat previously considered impossible due to noise and other issues. This allows the SP4000 to achieve an impressive SNR (signal-to-noise ratio) of 131 dB, matching the independent dual audio circuit 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 (True Quad DAC).
- Decoding: up to 32 Bit/768 kHz bit-perfect 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: 8 kHz ~ 768 kHz (8/16/24/32 Bit 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: Unbalanced 4.1 Vrms / Balanced 8.2 Vrms (no load).
- Frequency range:
Unbalanced: ±0.006dB - 20 Hz ~ 20 kHz.
Balanced: ±0.006dB - 20 Hz ~ 20 kHz
Unbalanced: ±0.06dB - 20 Hz ~ 70 kHz
Balanced: ±0.06dB - 20 Hz ~ 70 kHz - SNR: Unbalanced 129 dB @ 1kHz / Balanced 131dB @ 1kHz.
- Crosstalk: Unbalanced -136dB @ 1kHz / Balanced -145dB @ 1kHz.
- THD+N: Unbalanced 0.0005% @ 1kHz / Balanced 0.0003% @ 1kHz.
- Output impedance: Unbalanced 3.5 mm 0.7 Ohm / Balanced 4.4 mm 1.7 Ohm
- Clock jitter: 25pS (typical)
- Reference clock jitter: 200 femtoseconds
- Internal memory: 256 GB (NAND).
- microSD card slot for memory expansion (max. 1.5 TB).
- Battery: 6780 mAh 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 calf leather case from the German tannery Perlinger.
- USB cable (USB-C to USB-A)
- Protective film for the screen
- Quick start guide (German, French, English)
- User manual stored on the player in PDF format (German, French, English)
