{"product_id":"astell-kern-a-ultima-sp4000t","title":"Astell\u0026Kern A\u0026ultima SP4000T | Vacuum Tube Digital Audio Player","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0023\/9255\/5595\/files\/astell-kern-horizontal-logo-cf203a-red.jpg?v=1676570802\" alt=\"Astell\u0026amp;Kern product logo red\" style=\"display: block; margin-left: auto; margin-right: auto; width: 40%;\"\u003e\u003c\/p\u003e\n\u003ch4\u003eDiscover the Astell\u0026amp;Kern SP4000T, the Ultimate DAP, Where Analog Warmth and Digital Precision Collide\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eIndustry-first DAP with MIL-Spec Vintage Vacuum Tube Raytheon JAN6418 in Quad Configuration\u003c\/li\u003e\n\u003cli\u003eIndustry-first DAP with Triple Tube Mode (Triode, Ultra Linear, Pentode)\u003c\/li\u003e\n\u003cli\u003eT Series Signature feature: Triple AMP System\u003c\/li\u003e\n\u003cli\u003eAdjustable Tube Current with Three Levels\u003c\/li\u003e\n\u003cli\u003eHigh Driving Mode, ESA, and Advanced DAR for superior sound quality\u003c\/li\u003e\n\u003cli\u003eFull Open Android\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cimg alt=\"Astell\u0026amp;Kern SP4000t dap x2 silver and copper standing with vacuum tubes red background\" height=\"1200\" width=\"2048\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0023\/9255\/5595\/files\/ak-sp4000t-banner.webp?v=1781190040\"\u003e\u003c\/p\u003e\n\u003ch3\u003eA New Standard in Tube Configuration\u003c\/h3\u003e\n\u003cp\u003eWith independent dual-tube structures dedicated to the left and right channels respectively, the channel-separated design, once exclusive to home audio high-end tube amplifiers, has finally been brought to the world of DAPs.\u003c\/p\u003e\n\u003cp\u003eThe four tubes in the SP4000T work in a differential configuration, with each pair facing the other in mirror symmetry. In this precise balance, music signals are amplified with twice the clarity, while common-mode noise is mutually cancelled and eliminated.\u003c\/p\u003e\n\u003cp\u003eWhen four hearts beat as one in perfect balance, the tube's signature rich harmonics resonate with the deepest, most resonant sound ever heard in the SP4000T.\u003c\/p\u003e\n\u003ch3\u003eTriple Tube Mode\u003c\/h3\u003e\n\u003cp\u003eThe SP4000T is the industry's first DAP to feature Triple Tube Mode. Combined with the T Series Signature Triple AMP Mode and the Tube Current level adjustment first found on the SP3000T, it offers up to 54 possible combinations tailored to any genre or preference, a true Analog Sound Palette.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTriode Mode: The Purest Voice of the Tube\u003c\/strong\u003e\u003cbr\u003eThis mode brings out the richest harmonic texture unique to vacuum tubes, letting the breath of a vocalist and the trembling of strings gently dissolve into a lush, lingering reverb.\u003cbr\u003e\u003cbr\u003e\u003cstrong\u003eUltra Linear Mode: The Aesthetics of Balance\u003c\/strong\u003e\u003cbr\u003eA design that blends the tonal color of Triode with the output of Pentode. The sound fades softly at its edges, yet carries a firm, solid core.\u003cbr\u003e\u003cbr\u003e\u003cstrong\u003ePentode Mode: The Most Powerful Voice of the Tube\u003c\/strong\u003e\u003cbr\u003eMaximizing tube amplifier output and dynamic range, this mode retains the tube's signature warmth while stripping away reverb — delivering a clean, powerful presence that speaks with directness and force.\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"AstellnKern SP4000t dap silver and copper closeup of volume wheels\" height=\"1000\" width=\"2048\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0023\/9255\/5595\/files\/ak-sp4000t-lifestyle.webp?v=1781190545\"\u003e\u003c\/p\u003e\n\u003ch3\u003eThe Perfect Harmony\u003c\/h3\u003e\n\u003cp\u003eA\u0026amp;ultima SP4000T, built on Astell\u0026amp;Kern's exclusive Teraton Alpha technology, achieves a perfect fusion of true analog sound from the Quad-configured Real Vacuum Tubes and the dynamic sound of the OPAMP.\u003c\/p\u003e\n\u003cp\u003eSP4000T offers TUBE AMP mode for the authentic analog sound of a tube amplifier, OP AMP mode delivering Astell\u0026amp;Kern's signature clarity and expansive soundstage, and HYBRID AMP mode combining the best of both analog warmth and high-resolution output.\u003c\/p\u003e\n\u003ch3\u003eAnti-Microphonic Noise Architecture\u003c\/h3\u003e\n\u003cp\u003eThe greatest technical challenge in applying vacuum tubes to a compact portable device is achieving low noise even at high resolution and high output. SP4000T introduces an upgraded 5-stage 2nd Generation Architecture (up from the previous 4-stage design) to suppress microphonic noise (noise generated in vacuum tubes from even minor external vibrations). \u003c\/p\u003e\n\u003ch3\u003eHEXA Audio Circuit Structure\u003c\/h3\u003e\n\u003cp\u003eThe SP4000T integrates dual AK4499EX DACs, AKM’s latest flagship, paired with dedicated AK4191EQ processors for each left and right channel, forming a fully discrete audio circuit architecture.\u003c\/p\u003e\n\u003cp\u003eUnlike conventional DAPs that handle both digital and analog signals inside the DAC, the SP4000T's audio circuit uses a dedicated digital delta-sigma modulator (AK4191EQ) to reduce noise in the digital signal before passing it to a completely isolated Analog DAC (AK4499EX) for independent analog signal processing.\u003c\/p\u003e\n\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0023\/9255\/5595\/files\/ak-sp4000t-case.webp?v=1781190116\" width=\"2048\" height=\"1200\" alt=\"AstellnKern SP4000t dap rear left 3 quarter in leather case whitebox\"\u003e\u003c\/p\u003e\n\u003ch3\u003ePremium Leather Case\u003c\/h3\u003e\n\u003cp\u003eThe bundled leather case for the SP4000T was crafted using 'MINERVA' leather from 'BADALASSI CARLO', a renowned leather workshop located in the San Miniato district of Florence, Italy.\u003c\/p\u003e\n\u003cp\u003eVegetable tanning is an eco-friendly leather-making process, slow and time-intensive, that tans hides using only plant-derived tannin extracts. Badalassi Carlo leathers employ the Tuscan vacchetta technique, after removing the hair from the hide, bovine bone powder-derived tallow is added during the vegetable oil tanning process.\u003cbr\u003e\u003c\/p\u003e\n\u003ch3\u003eAdditional Features and Enhancements\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eAstell\u0026amp;Kern's TERATON ALPHA\u003c\/li\u003e\n\u003cli\u003eAstell\u0026amp;Kern Direct Path Customization Technology\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e99.9% Pure Copper Shield Can\u003c\/li\u003e\n\u003cli\u003eNative DSD512, 32-bit\/768kHz Support\u003c\/li\u003e\n\u003cli\u003eUSB PD 3.0 Fast Charging\u003c\/li\u003e\n\u003cli\u003eLarge 6\" Full HD Display\u003c\/li\u003e\n\u003cli\u003eEnhanced Battery Protection Mode\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Astell\u0026Kern","offers":[{"title":"Silver","offer_id":42674487918667,"sku":"AK-SP4000T-SLV","price":3620.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0023\/9255\/5595\/files\/ak-0-sp4000t-thumb.webp?v=1781189645","url":"https:\/\/bloomaudio.com\/products\/astell-kern-a-ultima-sp4000t","provider":"Bloom Audio","version":"1.0","type":"link"}