Astell & Kern / A&ultima SP4000T Silver

＜＜July 2026 New Product！＞＞The A&ultima SP4000T is a flagship-class DAP featuring a "Triple Tube Mode" and "Triple Amp System" based on a quad configuration of Raytheon JAN6418 vintage vacuum tubes—an industry first for MIL-spec compliant tubes.

■ [Reimagine Analog Sound] Industry-first quad Raytheon JAN6418 tube configuration
■ 2nd-generation anti-microphonic noise architecture
■ Industry-first Triple Tube Mode
■ Selectable tube current options and tube LED indicators
■ Seamless fusion of real vacuum tubes and op-amps; Triple Amp System
■ HEXA audio circuit structure with complete separation of digital and analog signals
■ High Driving Mode utilizing horizontally parallel-arranged op-amps
■ Proprietary ESA technology to minimize group delay
■ Any-Layer HDI PCB to minimize signal loss
■ 99.9% pure copper shielding
■ Android 15 OS with proprietary ADP technology to overcome SRC limitations
■ Advanced DAR utilizing VSE
■ Stainless Steel 316L housing material
■ Dual-antenna design, PD 3.0 fast charging support, and advanced battery protection modes
■ Superior audio performance and high expandability
■ Italian premium leather case
■ "Burst" design concept

■ Model Name: A&ultima SP4000T
■ Color: Silver
■ Body Material: Stainless Steel 316L (Silver)
■ Display: 6-inch 2K (2160×1080) touchscreen
■ Dimensions (W×H×D): 85.7mm × 150mm × 19.5mm
■ Weight: Approx. 565g
■ Firmware Update: OTA
■ Operating Temperature: 0°C to +40°C
■ Supported OS: Windows 10 (32/64bit), 11 (64bit) / macOS X 10.7
■ Internal Memory: 256GB [NAND] *Includes system area
■ External Memory Support: 1x microSD slot (Max 2TB)
■ Wi-Fi: 802.11 a/b/g/n/ac (2.4/5GHz)
■ Bluetooth: V5.2 (A2DP, AVRCP / SBC, AAC, Qualcomm aptX HD, LDAC, LHDC)
■ Supported file formats: WAV, FLAC, WMA, MP3, OGG, APE, AAC, ALAC, AIFF, DFF, DSF
■ CPU: Octa-core
■ DAC: AKM AK4191EQ x2 + AK4499EX x2 (Dual DAC)
■ Supported sampling rates:
・PCM max: 768kHz (16/24/32-bit)
・DSD max: DSD512 (22.4MHz/1-bit) Stereo
■ Input: USB Type-C (charging & data transfer)
■ Outputs:
・3.5mm 3-pole unbalanced output (shared optical digital output)
・4.4mm 5-pole balanced output (5-pole GND connection)
■ Output level: Unbalanced 4.2Vrms / Balanced 8Vrms (no load)
■ Output impedance: Unbalanced 3.5mm (0.7Ω) / Balanced 4.4mm (1.7Ω)
■ Frequency response:
・±0.006dB (20Hz–20kHz) Unbalanced / ±0.006dB (20Hz–20kHz) Balanced
・±0.06dB (20Hz–70kHz) Unbalanced / ±0.06dB (20Hz–70kHz) Balanced
■ S/N ratio: 124dB @ 1kHz, Unbalanced / 125dB @ 1kHz, Balanced
■ Crosstalk: -136dB @ 1kHz, Unbalanced / -145dB @ 1kHz, Balanced
■ THD+N: 0.0006% @ 1kHz, Unbalanced / 0.0004% @ 1kHz, Balanced
■ IMD: 0.0004% 800Hz 10kHz (4:1) Unbalanced / 0.0004% (800Hz/10kHz, 4:1, Balanced)
■ Clock Jitter: 25ps (Typ)
■ Reference Clock Jitter: 200 fs
■ Battery: 7,450mAh 3.8V Lithium-polymer
■ Charging Time: Approx. 5 hours (with PD 3.0 charging)
■ Playback Time: Approx. 10 hours (Normal Mode, FLAC, 44.1kHz/16-bit, Vol. 50, LCD off, Unbalanced output, LED on, OP Amp)
■ Included Accessories: SP4000T dedicated leather case, leather earphone pouch, USB Type-C to Type-C cable, screen protector, microSD card slot cover
■ Country of Manufacture: South Korea
■ Manufacturer Warranty: 1 year for the main unit / 90 days for accessories

* Please be sure to keep proof of purchase—such as a receipt, delivery note, or sales slip (showing the date)—for the product warranty.
* microSD card sold separately. Operation is not guaranteed for all microSD cards.
* Operation is not guaranteed for all Bluetooth devices.
* Separate music playback software is required to use the USB-DAC function. Operation is not guaranteed with all connected devices.
* Operation is not guaranteed with all connected devices when using USB audio output.
* This product uses MTP connection. If using a Mac, installation of file transfer software is required.
* Audio measurements are based on Normal Mode. Auto-mute is not used.
* The specifications above are based on information as of July 2026. Please note that specifications are subject to change without notice for quality improvement purposes.