Astell&Kern, a global leader in high-resolution audio products and accessories, expands its flagship Digital Audio Player line with the release of the Limited Edition A&ultima SP4000 Copper. The SP4000 Copper will be available in February 2026 for $4,100 at authorized Astell&Kern dealers worldwide and $4,499 from authorized US dealers.
The A&ultima SP4000 Copper Limited Edition is more than a flagship player, it is Astell&Kern’s ultimate showcase of material mastery, precision engineering, and pure analog sound expression. Built from 99.98% pure copper, it leverages a metal renowned for ideal audio properties yet notoriously difficult to use, requiring a multi-layer stabilization process and meticulous machining to achieve long-term durability and flawless finish.
This uncompromising craftsmanship directly shapes its sonic character. Copper’s natural conductivity and shielding help preserve even the finest details, resulting in sound that is uncolored, expressive, and profoundly lifelike. The SP4000 Copper delivers deep, authoritative bass, a rich and articulate midrange, and treble that decays with natural ease, all presented as a seamless, emotionally engaging whole.
Created for listeners who value the truth of the original recording, the SP4000 Copper Limited Edition reflects Astell&Kern’s pursuit of perfection without compromise—setting a new benchmark for what high-end portable audio can achieve.
The A&ultima SP4000 is Astell&Kern’s latest flagship digital audio player, the result of three years of relentless research and innovation following the development of the SP3000. As part of the A&ultima series—Astell&Kern’s flagship lineup combining cutting-edge technology and top-tier specifications—the SP4000 surpasses the boundaries set by the SP3000, once regarded as the ultimate reference. Built upon an advanced Octa audio circuit architecture, the SP4000 distills the purest essence of audio engineering, delivering a sound experience unlike anything before it—refined, powerful, and remarkably close to perfection.
The SP4000 series players debut a new 1:1 Octa Audio Circuit architecture—pairing one AK4191 processor with one AK4499EX DAC—to achieve a true Quad DAC design with lower noise, cleaner separation, and superior signal processing. Its split digital/analog design further reduces noise for an unprecedented level of sound purity. A new parallel OPAMP configuration expands driving power without raising noise, delivering greater dynamics and detail in High Driving Mode. Proprietary ESA technology minimizes group delay for clearer, more coherent audio, while an ultra-low-noise LDO regulator cuts power noise by up to 97%. Full Android OS integration with Astell&Kern’s ADP ensures bit-perfect playback even in streaming apps. Advanced DAR technology adds harmonic restoration and refined upsampling, and Any Layer HDI PCB plus a 99.9% pure copper Shield Can reduce signal loss and interference for a cleaner, more precise sound.
The SP4000 comes in a premium Shrunken Calf leather case crafted by Perlinger, Germany’s famed tannery known for over a century of luxury leather expertise. Made from soft calf hide and treated through chrome tanning, unique shrinking, and aniline dyeing with proprietary pigments, the leather retains its natural grain and develops a rich, enduring color. Perlinger’s advanced anti-aging process ensures long-lasting beauty and durability, giving the SP4000 a case that reflects true luxury craftsmanship.
The player includes 256GB of internal memory with support for microSD cards up to 1.5TB, dual-band 2.4/5Ghz a/b/g/n/ac Wi-Fi, DLNA networking, USB digital audio output, USB-C for data transfer and charging, and the ability to use the SP4000 as a USB DAC for your Mac or Windows-based PC. A 6” 2160x1080 touch screen provides up to 2K resolution. The SP4000 supports native playback of high-res PCM music up to 32-bit, 768kHz and DSD512.
ReplayGain keeps playback levels consistent across tracks, while AK File Drop enables seamless, wireless file transfers from devices on the same network—no cables required. The SP4000 expands wireless audio options with support for aptX™ Adaptive, LDAC™, and BT Sink mode, allowing it to function as a high-quality Bluetooth DAC for music from external devices. Fast and efficient Qualcomm QC 3.0 charging delivers a full charge in about four hours and up to ten hours of continuous playback. For more natural, speaker-like listening, the Crossfeed feature blends left and right channels with adjustable parameters—Shelf Cutoff, Shelf Gain, and Mixer Level—to reduce fatigue and tailor the effect to your preference. The SP4000 is Roon Ready certified.
The A&ultima SP4000 is also available now in black or silver 904L stainless steel for $4,290 in the US and $3,900 at authorized Astell&Kern dealers globally.
