{"product_id":"astell-kern-a-ultima-sp4000t-portable-tube-audio-player","title":"Astell\u0026Kern A\u0026ultima SP4000T Portable Tube Audio Player","description":"\u003cp\u003eThe Astell\u0026amp;Kern A\u0026amp;ultima SP4000T reimagines analog sound in a flagship portable player. It is the industry's first DAP with four MIL-Spec Raytheon JAN6418 vacuum tubes in a quad configuration, and the first with Triple Tube Mode (Triode, Ultra Linear and Pentode). Combined with the T Series Triple AMP system and three-level tube current adjustment, it offers up to 54 sound combinations. Available in Stainless Steel Silver, or as the Copper Edition machined from 99.98% pure copper.\u003c\/p\u003e\n\u003c!-- more --\u003e\u003c!--first paragraph--\u003e \u003c!--product details start--\u003e\n\u003cp\u003e\u003cstrong\u003eKey Features:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eIndustry-first DAP with four Raytheon JAN6418 MIL-Spec vintage vacuum tubes (Quad Tube)\u003c\/li\u003e\n\u003cli\u003eIndustry-first Triple Tube Mode: Triode, Ultra Linear and Pentode\u003c\/li\u003e\n\u003cli\u003eT Series Triple AMP system: Tube AMP, OP AMP and 5-stage Hybrid AMP\u003c\/li\u003e\n\u003cli\u003eThree-level adjustable tube current\u003c\/li\u003e\n\u003cli\u003eDual AK4191EQ + dual AK4499EX DACs in a HEXA audio circuit with fully separated digital and analog paths\u003c\/li\u003e\n\u003cli\u003eHigh Driving Mode, ESA (Enhanced Signal Alignment) and Advanced DAR\u003c\/li\u003e\n\u003cli\u003eNative DSD512 and 32-bit\/768kHz playback; bit-perfect streaming via Astell\u0026amp;Kern Direct Path\u003c\/li\u003e\n\u003cli\u003eFull open Android 15 with enhanced octa-core CPU, Roon Ready and Qobuz Connect\u003c\/li\u003e\n\u003cli\u003e6-inch Full HD (2160 x 1080) touchscreen and 256GB storage plus microSD up to 1.5TB\u003c\/li\u003e\n\u003cli\u003eBundled Italian Badalassi Carlo Minerva leather case in Cognac\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv class=\"details-content\"\u003e\n\u003cp class=\"product-tittle\"\u003e\u003cstrong\u003eRAYTHEON JAN6418 Quad: A New Standard in Tube Configuration\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"product-subcontent\"\u003eThe SP4000T uses independent dual-tube structures for the left and right channels, a channel-separated design once found only in high-end home tube amplifiers. The four tubes work in a mirror-symmetric differential configuration, so music is amplified with greater clarity while common-mode noise cancels out. Each tube is measured for noise and gain before pairing, then isolated on independent modular flexible PCBs.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"details-content\"\u003e\n\u003cp class=\"product-tittle\"\u003e\u003cstrong\u003eTriple Tube Mode\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"product-subcontent\"\u003eTriode mode brings out the richest harmonic texture and lingering reverb. Ultra Linear blends Triode tone with Pentode output for a balanced sound across every genre. Pentode maximises output and dynamic range for a clean, powerful presentation. Tube Mode applies in Tube AMP and Hybrid AMP modes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"details-content\"\u003e\n\u003cp class=\"product-tittle\"\u003e\u003cstrong\u003eTriple AMP System\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"product-subcontent\"\u003eBuilt on Astell\u0026amp;Kern's TERATON ALPHA technology, the SP4000T offers Tube AMP mode for authentic tube warmth, OP AMP mode for Astell\u0026amp;Kern's signature clarity and soundstage, and a five-stage Hybrid AMP mode that blends the two to your taste.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"details-content\"\u003e\n\u003cp class=\"product-tittle\"\u003e\u003cstrong\u003e2nd Generation Anti-Microphonic Architecture\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"product-subcontent\"\u003eA five-stage structure suppresses microphonic noise: a separate modular flexible PCB, a silicone base cushion, custom-fit silicone tubing around the tube leads, a silicone damper suspending each tube, and a copper shield can over the whole assembly. While in Tube or Hybrid mode, the tubes glow softly through the rear window.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"details-content\"\u003e\n\u003cp class=\"product-tittle\"\u003e\u003cstrong\u003eHEXA Audio Circuit\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"product-subcontent\"\u003eDual AK4499EX DACs are paired with dedicated AK4191EQ delta-sigma modulators for each channel. The digital signal is cleaned by the AK4191EQ before passing to the fully isolated analog DAC, giving complete physical separation of digital and analog signal paths.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"details-content\"\u003e\n\u003cp class=\"product-tittle\"\u003e\u003cstrong\u003eHigh Driving Mode, ESA and Advanced DAR\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"product-subcontent\"\u003eHigh Driving Mode uses parallel OPAMPs for greater driving power without added noise. ESA minimises group delay so all frequencies arrive more uniformly. Advanced DAR first restores lost harmonics with VSE, then upsamples for a fuller, more natural sound.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"details-content\"\u003e\n\u003cp class=\"product-tittle\"\u003e\u003cstrong\u003eSP4000T Copper Edition\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"product-subcontent\"\u003eThe Copper Edition is machined from high-purity (99.98%+) copper with a multi-layer coating that prevents oxidation and discolouration. Copper's conductivity and electromagnetic shielding protect the signal, while its natural resonance adds depth to the warm harmonics of the four vacuum tubes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"details-content\"\u003e\n\u003cp class=\"product-tittle\"\u003e\u003cstrong\u003eStreaming and Convenience\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"product-subcontent\"\u003eFull open Android 15 with bit-perfect Astell\u0026amp;Kern Direct Path playback, Roon Ready and Qobuz Connect support, BT Sink, a dual-antenna Wi-Fi design with around twice the 5GHz download speed of the previous model, USB PD 3.0 fast charging, 7 DAC filters, Crossfeed, ReplayGain and a bit-depth indicator LED around the power button.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"details-content\"\u003e\n\u003cp class=\"product-tittle\"\u003e\u003cstrong\u003ePremium Leather Case\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"product-subcontent\"\u003eThe bundled case is made from vegetable-tanned Minerva leather by Badalassi Carlo of Florence, Italy. It comes in Cognac and has a rear cutout that shows off the tube glow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c!--product details end--\u003e\n\u003c!--tech specs content start--\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eModel\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eSP4000T (PPF52)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBody Colour\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eSilver, Copper\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBody Material\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eStainless Steel, Copper\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDisplay\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e6-inch 2K (2160 x 1080) touchscreen\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSupported Audio Formats\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eWAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, DSF\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSample Rate\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePCM: 8kHz–768kHz (8\/16\/24\/32-bit)\u003cbr\u003eDSD Native: DSD64, DSD128, DSD256, DSD512 (Stereo)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOutput Level\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUnbalanced 4.2Vrms \/ Balanced 8Vrms (no load)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCPU\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eOcta-Core\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDAC\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eAKM AK4191EQ x2 + AK4499EX x2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eVacuum Tube\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eRaytheon JAN6418 x4 (Quad Tube)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDecoding\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUp to 32-bit\/768kHz bit-to-bit playback\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eInput\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUSB Type-C (charging, PC and Mac)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOutputs\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUnbalanced 3.5mm, Optical 3.5mm, Balanced 4.4mm (5-pole)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eAK Cradle Compatibility\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eSupported\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eWi-Fi\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e802.11 a\/b\/g\/n\/ac\/ax (2.4\/5GHz)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBluetooth\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eV5.2 (A2DP, AVRCP, aptX HD, LDAC, LHDC, SBC, AAC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFrequency Response\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e±0.006dB (20Hz–20kHz) \/ ±0.06dB (20Hz–70kHz), Unbalanced and Balanced\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eS\/N\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e124dB @ 1kHz Unbalanced \/ 125dB @ 1kHz Balanced\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCrosstalk\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e-136dB @ 1kHz Unbalanced \/ -145dB @ 1kHz Balanced\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eTHD+N\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e0.0006% @ 1kHz Unbalanced \/ 0.0004% @ 1kHz Balanced\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eIMD SMPTE\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e0.0004% 800Hz 10kHz (4:1) Unbalanced \/ Balanced\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOutput Impedance\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUnbalanced 3.5mm (0.7Ω) \/ Balanced 4.4mm (1.7Ω)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eClock Jitter\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e25pS (Typ); Reference Clock Jitter 200 femtoseconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBuilt-in Memory\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e256GB (NAND)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eExternal Memory\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003emicroSD x1 (max 1.5TB)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBattery\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e7,450mAh 3.8V Li-Polymer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCharge Time\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eAbout 5 hours (PD 3.0)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePlayback Time\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eAbout 10 hours (FLAC 16-bit\/44.1kHz, Vol. 80, LCD off, Low Gain)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDimensions\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e85.7mm (W) x 150mm (H) x 19.5mm (D)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eWeight\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eApprox. 565g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFirmware\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eOTA upgrade supported\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOperating Temperature\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e0°C to 40°C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSupported OS\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eWindows 10\/11 (32\/64-bit), macOS X 10.7+\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c!--tech specs content end--\u003e","brand":"Astell\u0026Kern","offers":[{"title":"Silver","offer_id":55011152953667,"sku":"AKP28","price":4499.0,"currency_code":"EUR","in_stock":true},{"title":"Copper","offer_id":55011152986435,"sku":"AKP29","price":4499.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0278\/4696\/7399\/files\/rep_6a8c4717ceeaf5df82dcdb92ce117be10.png?v=1793616556","url":"https:\/\/www.hifihut.ie\/products\/astell-kern-a-ultima-sp4000t-portable-tube-audio-player","provider":"HiFiHut","version":"1.0","type":"link"}