{"product_id":"astell-kern-a-ultima-sp4000-copper-limited-edition-portable-high-resolution-digital-audio-player","title":"Astell \u0026 Kern A\u0026ultima SP4000 Copper Limited Edition Portable High-Resolution Digital Audio Player","description":"\u003ch2\u003eLimited Edition Copper\u003c\/h2\u003e\n\u003cp\u003eThe A\u0026amp;ultima SP4000 Copper Limited Edition goes beyond a high-end portable audio player. It represents the culmination of Astell\u0026amp;Kern’s expertise in material engineering, precision manufacturing, and refined analog sound design.\u003c\/p\u003e\n\u003cp\u003eSP4000 Copper is the brand’s most definitive answer to a single question: how far can we go in the pursuit of the ultimate sound? Copper is theoretically one of the most ideal materials for audio, yet among the most difficult to use in real products. Its exceptional electrical conductivity and superior electromagnetic shielding minimize even the finest signal loss, but its rapid oxidation and low surface stability make practical application extremely challenging.\u003c\/p\u003e\n\u003cp\u003eIn portable devices, which are constantly exposed to temperature changes and external environments, copper becomes an even greater risk. Rather than avoiding this challenge, Astell\u0026amp;Kern confronted it directly, applying an advanced multi-layer coating process that requires high technical expertise to ensure the long-term stability of 99.98% pure copper.\u003c\/p\u003e\n\u003cp\u003eThe exterior, too, is never design for design’s sake. High-purity copper is highly susceptible to minute deformation during machining, yet Astell\u0026amp;Kern’s accumulated expertise enables precise control down to the finest tolerances. Through this process, the SP4000 Copper is realized not as a mass-produced device, but as a beautifully finished high-end audio object.\u003c\/p\u003e\n\u003cp\u003eMost importantly, the sound is the culmination of this relentless craftsmanship. Free from exaggeration or coloration, it delivers the texture and weight of instruments, the pace and breath of performance, rendered as an exceptionally refined expression of the original sound—enhanced by the inherent characteristics of copper.\u003c\/p\u003e\n\u003cp\u003eDeep, authoritative bass, a dense and articulate midrange, and treble that fades naturally come together as a single, cohesive flow, allowing emotion to be fully revealed through sound. Beyond simply “great sound,” it offers an experience where the true value of the original recording is faithfully realized.\u003c\/p\u003e\n\u003cp\u003eThe SP4000 Copper Limited Edition embodies Astell\u0026amp;Kern’s unwavering commitment to surpassing limits without compromise. Created for those who truly understand the essence of pure sound, SP4000 Copper sets a new standard for what high-end audio can be.\u003c\/p\u003e\n\u003ch2\u003eSP4000\u003c\/h2\u003e\n\u003cp\u003e\u003cimg alt=\"SP4000 lifestyle\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20250526153028_61dac1a4-88fa-49e2-a766-d04b3f292113.png?v=1749226540\"\u003e\u003c\/p\u003e\n\u003ch3\u003eBuilt on Legacy, Evolving Perfection\u003c\/h3\u003e\n\u003cp\u003eThe A\u0026amp;ultima SP4000 is Astell\u0026amp;Kern's newest flagship digital audio player, the result of three years of relentless research and innovation following the development of the SP3000.\u003c\/p\u003e\n\u003cp\u003eAs part of the A\u0026amp;ultima series-Astell\u0026amp;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.\u003c\/p\u003e\n\u003cp\u003eBuilt 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. Discover the SP4000 and experience sound on an entirely new level.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eEnhanced signal processing capabilities with Octa audio circuit architecture\u003c\/li\u003e\n\u003cli\u003eSupports High Driving Mode for delivering premium sound quality\u003c\/li\u003e\n\u003cli\u003eMinimizes group delay with proprietary ESA (Enhanced Signal Alignment) technology\u003c\/li\u003e\n\u003cli\u003eUltra Low Noise LDO Regulator for top-tier noise suppression\u003c\/li\u003e\n\u003cli\u003ePrecision sound achieved with Any Layer Type PCB\u003c\/li\u003e\n\u003cli\u003eEquipped with a 99.9% Pure Copper Shield Can\u003c\/li\u003e\n\u003cli\u003eFirst Astell\u0026amp;Kern Device to Support Full Android OS\u003c\/li\u003e\n\u003cli\u003eFirst Astell\u0026amp;Kern Device to Feature Advanced DAR Technology\u003c\/li\u003e\n\u003cli\u003eFeatures 4.5th generation UI, combining functionality and emotional design\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eEnhanced Signal Processing Capabilities with Octa Audio Circuit Architecture\u003c\/h3\u003e\n\u003cp\u003eIn the SP3000, the digital-to-analog signal processing structure was separated in a 1:2 ratio. With the SP4000, it has evolved into a 1:1 architecture.\u003c\/p\u003e\n\u003cp\u003eThis new structure, where one AK4191 digital processor is paired with one AK4499EX DAC, allows digital signals to be delivered precisely to a single DAC without the need to distribute noise, enabling improved signal separation and processing.\u003c\/p\u003e\n\u003cp\u003eThrough continuous research and innovation in circuit technology, the SP4000 successfully implements a true Quad DAC-a feat previously considered impossible due to noise and other issues. As a result, the SP4000 achieves an impressive SNR (Signal-to-Noise Ratio) of 131dB, on par with the independent dual audio circuit of its predecessor.\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cimg alt=\"Signal Separation Processing\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20250526153509_c6d73cc2-4350-4379-b72f-f978e87ad344.png?v=1749224613\"\u003e\u003cbr\u003e\u003cstrong\u003e[ Signal Separation Processing - 1:2 Structure ] --\u0026gt; [ Signal separation processing - 1:1 structure ]\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003eSupports High Driving Mode for Premium Sound Performance\u003c\/h3\u003e\n\u003cp\u003eThe SP4000 features twice as many OPAMPs arranged in parallel compared to its predecessor, delivering richer and more detailed sound. High Driving Mode provides powerful and stable output-much like a four-wheel-drive vehicle confidently navigating rough terrain. It's designed to reproduce even the most delicate sonic details with precision, allowing you to enjoy deeper, clearer, and more immersive music.\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"OPAMP : Series Configuration\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20250526153643_9ee294e9-d3df-4aa1-9f3d-362aa380e00d.png?v=1749224694\"\u003e\u003cbr\u003e\u003cstrong\u003e[ OPAMP : Series Configuration ]\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eDriving range increases linearly, but with increased noise and reduced SNR. While the sound may feel more powerful, it tends to become rougher or harsher.\u003c\/p\u003e\n\n\u003cp\u003e\u003cimg alt=\"OPAMP : Parallel Configuration\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20250526153649_134dd799-1db7-4df7-958f-48bcfa7d893d.png?v=1749224694\"\u003e\u003cbr\u003e\u003cstrong\u003e[ OPAMP : Parallel Configuration ]\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe driving range expands horizontally, with no increase in noise or reduction in SNR. This results in increased dynamic range and enhanced sound detail.\u003c\/p\u003e\n\u003ch3\u003eMinimized group delay with proprietary ESA (Enhanced Signal Alignment) technology\u003c\/h3\u003e\n\u003cp\u003eThe SP4000 features proprietary ESA (Enhanced Signal Alignment) technology, which significantly improves one of audio's long-standing challenges-group delay. ESA technology aligns frequency signals to arrive more uniformly, minimizing frequency distortion and dramatically enhancing sound clarity and purity.\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cimg alt=\"Enhanced Signal Alignment\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20250604125858_bcb912a6-06d0-41c7-bb3f-302f6e28028f.png?v=1749224832\" style=\"background-color: black;\"\u003e\u003cbr\u003e\u003cstrong\u003e[ Without ESA ] --\u0026gt; [ With ESA ]\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e*What is Group Delay? \u003cbr\u003eIn audio, group delay refers to the time differences it takes for various frequencies to pass through an internal system. In other words, each frequency reaches the output at slightly different times. Simply put, it describes a phenomenon where different frequencies within an audio signal do not arrive simultaneously, resulting in slight delays.\u003c\/p\u003e\n\u003ch3\u003eTop-Tier Noise Suppression (Ultra Low Noise LDO Regulator)\u003c\/h3\u003e\n\u003cp\u003eThe SP4000 features a newly implemented LDO (Low Dropout) Regulator in its power supply,which reduces noise by up to 97% compared to previous models. LDO Regulators are high-performance components typically used in precision medical devices and 5G communication equipment. They help stabilize battery voltage and effectively suppress noise, resulting in cleaner, purer sound.\u003c\/p\u003e\n\u003ch3\u003ePrecision Sound with Any Layer HDI PCB\u003c\/h3\u003e\n\u003cp\u003eTo achieve the highest sound quality, the SP4000 incorporates top-tier Any Layer HDI (High-Density Interconnect) PCB technology. Commonly used in smartphones and high-performance electronic devices, this advanced circuit board allows for the precise design of complex circuitry within a compact space. It minimizes signal loss, enabling the delivery of a more refined and detailed sound.\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"SP3000 Layer Structure\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20250604125727_2afdbea4-90f6-4ba8-9138-143bab85c7d4.png?v=1749225021\"\u003e\u003cbr\u003e\u003cstrong\u003e[ SP3000 Layer Structure ]\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003e\u003cimg alt=\"SP4000 Layer Structure\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20250604125731_db99907d-58e4-4562-92b6-eaff52d40c55.png?v=1749225022\" style=\"margin-bottom: 16px;\"\u003e\u003cbr\u003e\u003cstrong\u003e[ SP4000 Layer Structure ]\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch3\u003eEquipped with 99.9% Pure Copper Shield Can\u003c\/h3\u003e\n\u003cp\u003eThe SP4000 is equipped with a precision-engineered Shield Can to block various types of noise and electromagnetic interference that could affect the audio block. For the first time in Astell\u0026amp;Kern's lineup, a 99.9% pure copper Shield Can is used-providing not only exceptional shielding performance but also delivering sound that is clearer and more distinct than ever before.\u003c\/p\u003e\n\u003ch3\u003eSound, Infinite Possibilities\u003c\/h3\u003e\n\u003cp\u003e\u003cimg alt=\"Audio design\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20220831141537_f9441859-4b87-4207-b0b1-cab84134c0c5-gif-978x269--06-06-2025_11_54_AM.png?v=1749225305\"\u003e\u003c\/p\u003e\n\u003ch3\u003eAstell\u0026amp;Kern's First-Ever Full Android OS Integration\u003c\/h3\u003e\n\u003cp\u003eAstell\u0026amp;Kern has overcome Android OS's sampling limitation (SRC) through its proprietary customization technology, ADP (Astell\u0026amp;Kern Direct Path). This allows for bit-perfect, lossless playback even in streaming environments, ensuring the highest possible sound quality during music listening.\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"Direct Path Flow\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20250530172103_87fcbc3c-eaf8-42b7-bb1d-578dc0fb753a.png?v=1749225351\"\u003e\u003cbr\u003e\u003cstrong\u003e[ Astell\u0026amp;Kern Direct Path Flow ]\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eIn response to the growing shift toward streaming-based music consumption, Astell\u0026amp;Kern has integrated full Android OS for the first time. The SP4000 not only delivers flagship-level audio quality but also offers enhanced convenience, marking its evolution into a highly refined next-generation digital audio player.\u003c\/p\u003e\n\u003ch3\u003eFirst-Ever Implementation of Advanced DAR by Astell\u0026amp;Kern\u003c\/h3\u003e\n\u003cp\u003eThe SP4000 introduces Advanced DAR, Astell\u0026amp;Kern's second-generation DAR (Digital Audio Remaster) technology, delivering sound that is even more natural and refined. Rather than sending the audio file directly to the DAR engine, the SP4000 first uses VSE (Virtual Sound Extender) to virtually restore lost harmonics, enhancing the sound quality at the initial stage.\u003c\/p\u003e\n\u003cp\u003eThen, the advanced DAR engine performs a second-stage upsampling process with greater precision and completeness. This two-step approach allows listeners to enjoy a deeper, more immersive sound that comes closer than ever to the original recording.\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cimg alt=\"DAR engine\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20250526153949_08a2655a-ed36-4263-ac55-808242a85b84.png?v=1749225429\"\u003e\u003cbr\u003e\u003cstrong\u003e[ Lossy audio above 16kHz ] --\u0026gt; \u003c\/strong\u003e\u003cstrong\u003e[ Data restoration through VSE ] --\u0026gt; \u003c\/strong\u003e\u003cstrong\u003e[ DAR applied after data restoration ]\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable style=\"width: 100%;\" width=\"100%\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 25%;\"\u003e\u003cstrong\u003eDAR option\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 75%;\"\u003e\u003cstrong\u003eMaximum Conversion Rate\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 25%;\"\u003ePCM\u003c\/td\u003e\n\u003ctd style=\"width: 75%;\"\u003e\n\u003cul\u003e\n\u003cli\u003e44.1kHz range PCM will be converted to 352.8kHz for playback\u003c\/li\u003e\n\u003cli\u003e48kHz range PCM will be converted to 384kHz for playback\u003c\/li\u003e\n\u003cli\u003eNo conversion will be made when playing DSD with this option selected\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 25%;\"\u003eDSD\u003c\/td\u003e\n\u003ctd style=\"width: 75%;\"\u003e\n\u003cul\u003e\n\u003cli\u003ePCM files lower than 96kHz will be converted to DSD128 for playback\u003c\/li\u003e\n\u003cli\u003ePCM files over 96kHz will be converted to DSD256 for playback\u003c\/li\u003e\n\u003cli\u003eDSD files below DSD256 will be converted DSD256 for playback with this option selected\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e* The DAR function can be turned on and off and you may select it to suit the source sound and your own preferences.\u003c\/p\u003e\n\u003cp\u003e* Max PCM rate 384kHz\/DSD64 conversion play is supported, and the files will be converted to and played in the sample rates that fit the source sound.\u003c\/p\u003e\n\u003ch3\u003eDrive Your Music, Latest Snapdragon Octa-Core CPU for the Newest Flagship Device\u003c\/h3\u003e\n\u003cp\u003eA\u0026amp;ultima SP4000 is equipped with a Snapdragon 6125 Octa-core processor, so you can enjoy the overwhelming sound, faster system response and a redesigned generation user interface that moves comfortably and smoothly.\u003c\/p\u003e\n\u003cp\u003eFeaturing a high-performance CPU and improved 8GB of DDR4 memory, which is twice the amount commonly used, the more powerful system is stable with fast and fluid movement.\u003c\/p\u003e\n\u003cp\u003eThe CPU, memory and wireless communication parts are configured as one module, with the digital circuit parts arranged in the same area creating a single system on a chip (SoC). This maximizes the efficiency of the overall circuit configuration by providing more audio-only circuit space as well as reducing heat and noise from digital circuits.\u003c\/p\u003e\n\u003ch3\u003eEnhanced 4.5th-Generation UI That Blends Function and Emotion\u003c\/h3\u003e\n\u003cp\u003eThe SP4000 features an upgraded UI that balances both functionality and emotional experience. The main screen includes an immersive animation where an LP appears to slide in and out as you swipe through albums-turning the act of choosing music into a visually engaging and tactile experience.\u003c\/p\u003e\n\u003cp\u003eThe interface retains Astell\u0026amp;Kern's signature Crimson theme, reflecting the brand's identity and capturing its distinct emotional sensibility in a refined, modern design.\u003c\/p\u003e\n\u003ch3\u003eCrimson Theme + Interation\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eEdge\u003c\/p\u003e\n\u003cp\u003eClean, angular lines echo the physical design of the device, seamlessly blending its identity into the screen for a striking, edge-defined aesthetic.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSimple\u003c\/p\u003e\n\u003cp\u003eDespite its wide range of features, the interface is designed to be intuitive and user-friendly. Graphics are kept simple and unobtrusive, allowing users to focus entirely on the current screen without distraction.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSensibility\u003c\/p\u003e\n\u003cp\u003eMotion effects enhance emotional engagement and improve user interaction.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eMaterial Innovations, Use stainless steel 904L on DAP body material\u003c\/h3\u003e\n\u003cp\u003eTo achieve the goal of the A\u0026amp;ultima series, which is 'to provide the best value that no one can imitate while using the most innovative and uncompromising design and craftsmanship', the SP4000 uses 904L stainless steel material that has never been attempted before in a portable audio player. Using this material has expanded its value from just a digital device to the realm of a luxury good.\u003c\/p\u003e\n\u003cp\u003e904L stainless steel is harder and more difficult to process than general stainless steel requiring significantly more time and effort. However, due to its excellent durability and corrosion resistance, it has a characteristic that does not lose its beauty and is why it is used in expensive luxury watches where perfection in all materials and parts must be pursued with an irreplaceable and wonderful luster. Experience the uncompromising beauty and luxury of the SP4000 produced by Astell\u0026amp;Kern's experienced craftsmanship.\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"SP4000 lifestyle colors\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20250526153015_15c0e2af-73db-4b1d-81e7-f537305633dd.png?v=1749226539\"\u003e\u003c\/p\u003e\n\u003ch3\u003eSound Design Through DAC Filters\u003c\/h3\u003e\n\u003cp\u003eWith the SP4000, you can enjoy the fun of creating your own sound style by directly selecting various DAC filters provided by the DAC manufacturer. Design your own sound through 6 DAC filters.\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"DAC Filters\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/Astell-Kern-06-06-2025_12_03_PM.png?v=1749225825\"\u003e\u003c\/p\u003e\n\u003ch3\u003eReal-Time Information with LED Lights\u003c\/h3\u003e\n\u003cp\u003eThe LED light surrounding the power button provides information on the Bit Depth of the currently playing song, and also adds a visually pleasing element by making it shine and stand out.\u003c\/p\u003e\n\u003cp\u003e* The LED light can be turned on or off according to user settings.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003ered 16bit\u003c\/li\u003e\n\u003cli\u003egreen 24bit\u003c\/li\u003e\n\u003cli\u003eblue 32bit\u003c\/li\u003e\n\u003cli\u003epurple DSD\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cimg alt=\"SP4000 lifestyle edge\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20250526153024_8a54282f-5c7f-44eb-b6d4-9eec8ce12066.png?v=1749226539\"\u003e\u003c\/p\u003e\n\u003ch3\u003eOther Features\u003c\/h3\u003e\n\u003ch4\u003eCrossfeed, Speaker effect when listening through headphones\u003c\/h4\u003e\n\u003cp\u003eCrossfeed mixes parts of the original signal from one channel and sends that signal to the opposite channel with a time difference to center the sound image. Through the use of detailed settings such as Shelf Cutoff, Shelf Gain, and Mixer Level, you can set the level of crossfeed according to your listening preferences.\u003c\/p\u003e\n\u003ch4\u003eAdoption of 6 inch 2180x1080 2K Display\u003c\/h4\u003e\n\u003cp\u003eExperience the SP4000 more conveniently and comfortably with a wide 6-inch, large-screen 2180x1080 2K display.\u003c\/p\u003e\n\u003ch4\u003eAK File Drop to enjoy wireless transfers\u003c\/h4\u003e\n\u003cp\u003eThe new AK File Drop function in the SP4000 makes files transfers easier and more convenient. Using AK File Drop, you can freely transfer files wirelessly through a PC, smartphone, or FTP program located on the same network. Music file management is now possible with a cableless, wireless solution.\u003c\/p\u003e\n\u003ch4\u003eReplayGain Automatically and Uniformly Adjusts Playback Volume\u003c\/h4\u003e\n\u003cp\u003eReplayGain for Automatic Volume Level Adjustment ReplayGain functionality, which adjusts audio sources with varying volume levels to a uniform loudness, has been implemented. Enjoy your personalized playlists with the ReplayGain feature. * ReplayGain supports up to 24bit\/192kHz audio sources.\u003c\/p\u003e\n\u003ch4\u003ePD 3.0 Fast Charging Supported\u003c\/h4\u003e\n\u003cp\u003eThe SP4000 supports Qualcomm QC 3.0 fast charging, so you can charge your DAP faster and more efficiently than previous models, reaching a full charge in about 4 hours.\u003c\/p\u003e\n\u003ch4\u003eWireless Hi-Fi Sound via BT Sink\u003c\/h4\u003e\n\u003cp\u003eThe BT Sink function allows you to connect the SP4000 to an external device via Bluetooth, similar to connecting a smartphone to a BT speaker. Music being played on the external device can be transmitted to the SP4000 through the BT Sink function.\u003c\/p\u003e\n\u003ch3\u003ePremium Shrunken Calf Leather Case from Germany's Finest Leather House\u003c\/h3\u003e\n\u003cp\u003eThe SP4000 is packaged with a premium leather case crafted from Shrunken Calf by Perlinger, Germany's world-renowned leather house. Founded in 1864 and spanning five generations of craftsmanship, Perlinger supplies the finest leather to luxury brands across the globe-blending time-honored tradition with modern techniques.\u003c\/p\u003e\n\u003cp\u003eThe Shrunken Calf leather used in the case is made from the soft, delicate hide of calves under one year old. It is processed using a chrome tanning method to preserve its natural texture, then uniquely shrunk using special agents-not heat-to retain its organic grain and wrinkles.\u003c\/p\u003e\n\u003cp\u003eFollowing an aniline dyeing process, Perlinger's proprietary pigments are added to achieve a deep, vibrant color. Their advanced anti-aging treatment ensures that this richness lasts over time, complementing the SP4000 with a leather case that embodies lasting beauty, durability, and luxury.\u003c\/p\u003e\n\u003ch2\u003eDESIGN\u003c\/h2\u003e\n\u003cp\u003e'Pierce: The force of light that pierces through the darkness.'\u003c\/p\u003e\n\u003cp\u003eThe SP4000 stands at the pinnacle of Astell\u0026amp;Kern's flagship A\u0026amp;ultima line-a DAP that embodies the peak of performance and design. Like the The force of light that pierces through the darkness, the rotating volume wheel generates energy that is visualized as shards breaking through a solid wall. This imagery is captured through sharp edges, restrained detailing, and geometric structures, expressing both explosive force and concentrated power. The interplay of contrasting surfaces and multidimensional forms goes beyond aesthetics, serving as a visual representation of the SP4000's high-performance audio capabilities. Even the angle of the volume wheel's patterns has been meticulously crafted to deliver subtle tactile resistance, offering a sensory experience that connects users to the sound itself. It's not just about control-it's an intuitive, emotional interaction with music.\u003c\/p\u003e\n\u003cp\u003eThe choice of materials in the SP4000 perfectly embodies both technology and emotion. The front features high-gloss polished 904L stainless steel, while the rear is finished with PVD-coated ceramic, offering exceptional craftsmanship in both form and function.\u003c\/p\u003e\n\u003cp\u003eThe SP4000 is more than just a digital audio player-it is a work of art where technology, design, intuition, and performance converge, expressing a pure passion for the ultimate sound experience.\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"SP4000 lifestyle sleek\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/20250526153020_22b782dd-92ec-4151-a81b-a875bc17015d.png?v=1749226539\"\u003e\u003c\/p\u003e\n\u003ch2\u003eSpecification\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eGeneral Specifications\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel\u003c\/strong\u003e\n\u003cp\u003eSP4000 (PPF51)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBody Color\u003c\/strong\u003e\n\u003cp\u003eCopper\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBody Material\u003c\/strong\u003e\n\u003cp\u003eStainless Steel 904L\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDisplay\u003c\/strong\u003e\n\u003cp\u003e6inch 2K (2160 x 1080) touch screen\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupported Audio Formats\u003c\/strong\u003e\n\u003cp\u003eWAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, DSF\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSample rate\u003c\/strong\u003e\n\u003cp\u003ePCM : 8kHz ~ 768kHz (8\/16\/24\/32bits per Sample) \u003cbr\u003eDSD Native : DSD64(1bit 2.8MHz), Stereo | DSD128(1bit 5.6MHz), Stereo \u003cbr\u003eDSD256(1bit 11.2MHz), Stereo | DSD512(1bit 22.4MHz), Stereo\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutput Level\u003c\/strong\u003e\n\u003cp\u003eUnbalanced 4.1Vrms │ Balanced 8.2Vrms (Condition No Load)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCPU\u003c\/strong\u003e\n\u003cp\u003eOcta-core\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDAC\u003c\/strong\u003e\n\u003cp\u003eAKM4191 x4 + AKM4499EX x4 (Real Quad DAC)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDecoding\u003c\/strong\u003e\n\u003cp\u003eSupport up to 32bit \/ 768kHz Bit to Bit playback\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInput\u003c\/strong\u003e\n\u003cp\u003eUSB Type-C input (for charging \u0026amp; PC \u0026amp; MAC)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutputs\u003c\/strong\u003e\n\u003cp\u003eUnbalanced Out (3.5mm), Optical Out(3.5mm) \u003cbr\u003eBalanced Out (4.4m, only 5-pole supported)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWi-Fi\u003c\/strong\u003e\n\u003cp\u003e802.11 a\/b\/g\/n\/ac (2.4\/5GHz)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBluetooth\u003c\/strong\u003e\n\u003cp\u003eV5.0 (A2DP, AVRCP, Qualcomm® aptX™ HD, LDAC, LHDC, SBC, AAC)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions\u003c\/strong\u003e\n\u003cp\u003e3.34\" (85mm)[W] x 5.89\" (149.8mm)[H] x 0.76\" (19.5mm)[D]\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e\n\u003cp\u003eAbout 21.7oz (615g)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFeature Enhancements\u003c\/strong\u003e\n\u003cp\u003eFirmware upgrade supported (OTA)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperating Temperature\u003c\/strong\u003e\n\u003cp\u003e0℃ ~ + 40℃ (32℉~ 104℉)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003eAudio Specifications\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFrequency Response\u003c\/strong\u003e\n\u003cp\u003e±0.006dB (Condition : 20Hz~20kHz) Unbalanced │ ±0.006dB (Condition : 20Hz~20kHz) Balanced±0.06dB (Condition : 20Hz~70kHz) Unbalanced │ ±0.06dB (Condition : 20Hz~70kHz) Balanced\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eS\/N\u003c\/strong\u003e\n\u003cp\u003e129dB @ 1kHz, Unbalanced │ 131dB @ 1kHz, Balanced\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCrosstalk\u003c\/strong\u003e\n\u003cp\u003e-136dB @ 1kHz, Unbalanced │ -145dB @ 1kHz, Balanced\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTHD+N\u003c\/strong\u003e\n\u003cp\u003e0.0005% @ 1kHz, Unbalanced │ 0.0003% @ 1kHz, Balanced\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIMD SMPTE\u003c\/strong\u003e\n\u003cp\u003e0.0004% 800Hz 10kHz (4:1) Unbalanced │Balanced\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutput Impedance\u003c\/strong\u003e\n\u003cp\u003eUnbalanced Out 3.5mm (0.7ohm) │ Balanced Out 4.4mm(1.7ohm)\u003cbr\u003e*Audio measurements are based on the Normal mode.\u003cbr\u003e*Auto Mute is not used during audio testing.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003eClock Source\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eClock Jitter\u003c\/strong\u003e\n\u003cp\u003e25pS (Typ)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReference Clock Jitter\u003c\/strong\u003e\n\u003cp\u003e200 Femto Seconds\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003eStorage Capacity\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBuilt-in Memory\u003c\/strong\u003e\n\u003cp\u003e256GB [NAND]\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExternal Memory\u003c\/strong\u003e\n\u003cp\u003emicroSD x1 (Max. 1.5TB)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003eBattery\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCapacity\u003c\/strong\u003e\n\u003cp\u003e6,780mAh 3.8V Li-Polymer\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCharge Time\u003c\/strong\u003e\n\u003cp\u003eabout 4hours (QC3.0 Charging)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePlayback Time\u003c\/strong\u003e\n\u003cp\u003eabout 10hours (Standard : FLAC, 16bit, 44.1kHz, Vol.50, LCD Off)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003eSupported OS\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupported OS\u003c\/strong\u003e\n\u003cp\u003eWindows 10,11(32\/64bit) MAC OS X 10.7\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003eEtc\n\u003cul\u003e\n\u003cli\u003e\nAudio measurements are based on the Normal mode.\u003c\/li\u003e\n\u003cli\u003eAuto Mute is not used during audio testing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Astell \u0026 Kern","offers":[{"title":"Default Title","offer_id":50099190268137,"sku":"SP4000 Copper","price":4499.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/SP4000C_002copy.jpg?v=1770327930","url":"https:\/\/audio46.mom\/products\/astell-kern-a-ultima-sp4000-copper-limited-edition-portable-high-resolution-digital-audio-player","provider":"Audio46 Headphone Store","version":"1.0","type":"link"}