Astell&Kern SP4000T
Experience the Warmth of True analogue Sound
The Astell&Kern SP4000T is a flagship portable music player designed for listeners who want the emotional character of analogue audio combined with the precision of modern digital technology. Built around a unique vacuum tube architecture, the SP4000T delivers rich, immersive sound with exceptional detail, depth, and musicality.
Key Features
Quad Vacuum Tube Technology
The SP4000T is the first portable digital audio player to feature four Raytheon JAN6418 vacuum tubes. This advanced tube design creates a warm, natural presentation while maintaining outstanding clarity and channel separation.
Triple Tube Modes
Choose from three distinct tube sound signatures to match your music and listening preferences:
- Triode Mode – Warm, rich, and expressive with enhanced harmonics.
- Ultra Linear Mode – Balanced and versatile with excellent detail.
- Pentode Mode – Dynamic, powerful, and highly energetic.
Triple Amplifier System
The SP4000T offers three amplifier options:
- Tube Amp Mode for authentic analogue warmth.
- OP Amp Mode for maximum resolution and accuracy.
- Hybrid Amp Mode that blends tube character with digital precision.
This flexibility allows listeners to tailor the sound to their headphones, music genre, and personal preferences.
Advanced Audio Architecture
A dedicated dual-DAC and dual-processor design keeps digital and analogue signal paths completely separated, helping reduce noise and preserve musical detail. The result is a cleaner, more natural listening experience.
Enhanced Noise Control
A sophisticated multi-layer vibration isolation system minimizes unwanted tube noise, allowing the vacuum tubes to perform at their best even in a portable device.
High-Resolution Audio Support
The SP4000T supports a wide range of high-resolution audio formats, including PCM up to 32-bit/768kHz and native DSD512 playback.
High Driving Mode
For demanding headphones and in-ear monitors, High Driving Mode delivers increased power, improved dynamics, and greater sonic authority while maintaining low noise levels.
Streaming Ready
Running Android 15, the SP4000T provides access to popular streaming services while maintaining bit-perfect playback through Astell&Kern's proprietary Direct Path technology.
Premium Connectivity
Features include:
- Dual-band Wi-Fi
- Bluetooth 5.2
- LDAC, aptX HD, and LHDC codec support
- Balanced 4.4mm and 3.5mm outputs
- USB-C connectivity
- Roon Ready compatibility
- Qobuz Connect support
Designed for Audiophiles
The SP4000T combines precision engineering with premium materials, including stainless steel and copper construction. Its distinctive design reflects the power and energy of its analogue-inspired sound while providing a comfortable and luxurious user experience.
A large 6-inch Full HD touchscreen offers intuitive control, while custom LED lighting provides visual feedback during playback.
Premium Leather Case Included
Each SP4000T includes a handcrafted Italian leather case made from premium vegetable-tanned leather. Designed specifically for the player, it offers protection while preserving the device's distinctive appearance.
A New Reference in Portable Audio
Combining true vacuum tube technology, advanced digital engineering, and extensive sound customization options, the Astell&Kern SP4000T delivers a uniquely engaging listening experience for serious music enthusiasts.
General Specifications
| Specification |
Details |
| Model |
SP4000T (PPF52) |
| Product Type |
Portable High-Resolution Digital Audio Player (DAP) |
| Body Colours |
Silver, Copper |
| Chassis Materials |
Stainless Steel, Copper |
| Display |
6-inch 2K Touchscreen |
| Resolution |
2160 × 1080 |
| Processor |
Octa-Core CPU |
| Operating System |
Full Open Android |
| Internal Storage |
256GB NAND Flash |
| Expandable Storage |
microSD Card Slot (up to 1.5TB) |
| Dimensions |
85.7 × 150 × 19.5 mm |
| Weight |
Approx. 544g |
| Operating Temperature |
0°C to +40°C |
| Firmware Updates |
OTA (Over-the-Air) Supported |
Audio Architecture
| Specification |
Details |
| DAC Configuration |
Dual AKM AK4191EQ + Dual AKM AK4499EX |
| Audio Circuit Design |
Fully Separated Digital & Analog Architecture |
| Vacuum Tubes |
4 × Raytheon JAN6418 |
| Tube Modes |
Triode, Ultra Linear, Pentode |
| Amplifier Modes |
Tube AMP, OP AMP, Hybrid AMP |
| Tube Current Levels |
3 Selectable Levels |
| High Driving Mode |
Yes |
| Advanced DAR |
Yes |
| ESA Technology |
Yes |
Supported Audio Formats
- WAV
- FLAC
- WMA
- MP3
- OGG
- APE
- AAC
- ALAC
- AIFF
- DFF
- DSF
Supported Sample Rates
PCM
- 8kHz – 768kHz
- 8 / 16 / 24 / 32-bit
Native DSD
- DSD64 (2.8MHz)
- DSD128 (5.6MHz)
- DSD256 (11.2MHz)
- DSD512 (22.4MHz)
Decoding Capability
- Bit-to-Bit playback up to 32-bit / 768kHz
Output Specifications
| Specification |
Unbalanced |
Balanced |
| Output Voltage |
4.2Vrms |
8.0Vrms |
| Frequency Response (20Hz–20kHz) |
±0.006dB |
±0.006dB |
| Frequency Response (20Hz–70kHz) |
±0.06dB |
±0.06dB |
| Signal-to-Noise Ratio |
124dB |
125dB |
| Crosstalk |
-136dB |
-145dB |
| THD+N |
0.0006% |
0.0004% |
| Output Impedance |
0.7Ω |
1.7Ω |
Connections
Outputs
- 3.5mm Headphone Output
- 3.5mm Optical Digital Output
- 4.4mm Balanced Headphone Output (5-pole)
USB
- USB Type-C
- Charging
- Data Transfer
- USB DAC Functionality
Wireless Connectivity
Wi-Fi
- IEEE 802.11 a/b/g/n/ac/ax
- 2.4GHz / 5GHz
Bluetooth
- Bluetooth 5.2
- A2DP
- AVRCP
- SBC
- AAC
- LDAC
- LHDC
- Qualcomm aptX HD
Clock Performance
| Specification |
Value |
| Clock Jitter |
25ps (Typical) |
| Reference Clock Jitter |
200 Femtoseconds |
Battery
| Specification |
Details |
| Battery Type |
Li-Polymer |
| Capacity |
7,450mAh / 3.8V |
| Playback Time |
Up to 10 Hours |
| Charging Time |
Approx. 5 Hours |
| Fast Charging |
USB PD 3.0 |
Included Technologies
- Quad Vacuum Tube Design
- Triple Tube Mode
- Triple AMP Mode
- High Driving Mode
- Advanced DAR
- ESA (Enhanced Signal Alignment)
- Full Open Android Platform
- Bit-Perfect Playback
- OTA Firmware Updates
- Wi-Fi 6 Connectivity
Compatibility
Supported Operating Systems
- Windows 10
- Windows 11
- macOS 10.7 and later
Manufacturer
Astell&Kern
Model Number
PPF52
Product Category
Flagship Portable Hi-Res Digital Audio Player (DAP)
