Astell&Kern A&ultima SP4000T Portable High-Resolution Music Player

Experience the Perfect Balance of Analogue Warmth and Digital Precision

The Astell&Kern A&ultima SP4000T is the most advanced portable music player ever created by Astell&Kern, bringing together true vacuum tube technology, flagship AKM DAC architecture and reference-grade engineering in a single luxury digital audio player.

Building upon the acclaimed SP4000 platform, the SP4000T introduces the world’s first Triple Tube Mode, allowing listeners to experience the distinctive character of a genuine tube amplifier wherever they go. Combined with Astell&Kern’s innovative Triple AMP System, the SP4000T offers an unprecedented level of control over your music, whether you prefer the warmth of valves, the precision of solid-state amplification or the perfect balance of both.

For serious audiophiles, this is more than just a digital audio player—it’s a portable reference system.

Four Real Vacuum Tubes. Endless Musical Possibilities.

Unlike products that simply emulate tube sound digitally, the SP4000T features four genuine Raytheon JAN6418 vacuum tubes, carefully selected and matched for exceptionally low noise and consistent performance.

Astell&Kern’s groundbreaking Triple Tube Mode lets you choose between:

• Triode Mode – Rich harmonics, organic vocals and beautifully natural decay.
• Ultra Linear Mode – The ideal balance between warmth, detail and control.
• Pentode Mode – Dynamic, energetic and highly resolving with exceptional impact.

Combined with Tube, Hybrid and OP AMP amplification modes, plus three selectable Tube Current settings, the SP4000T delivers up to 54 unique sound combinations, allowing you to tailor the presentation to your headphones, IEMs, music genre and personal taste.

Triple AMP System

The SP4000T gives you complete flexibility with three distinct amplifier paths:

• Tube AMP Mode for authentic analogue warmth and immersive musicality.
• OP AMP Mode for ultimate transparency, speed and resolution.
• Hybrid AMP Mode combining tube richness with the authority and precision of Astell&Kern’s solid-state design.

Whether you’re listening to intimate jazz recordings, orchestral works or modern electronic music, the SP4000T adapts effortlessly to your preferences.

Flagship AKM DAC Architecture

At the heart of the SP4000T are:

• Dual AK4191EQ Digital Processors
• Dual AK4499EX Flagship DACs

By physically separating digital and analogue signal processing, Astell&Kern dramatically reduces noise and distortion while improving timing accuracy and overall musical realism.

The result is exceptional detail retrieval, outstanding channel separation and an expansive soundstage that places every instrument precisely within the recording.

Built for Demanding Headphones

The SP4000T is designed to drive everything from the most sensitive in-ear monitors like the Clarus to demanding full-size headphones.

With up to 8Vrms balanced output, High Driving Mode and Astell&Kern’s proprietary TERATON ALPHA technology, the SP4000T delivers effortless dynamics, excellent control and remarkable low-level detail without sacrificing refinement.

Reference-Level High Resolution Audio

The SP4000T supports virtually every major high-resolution audio format including:

• PCM up to 32-bit / 768kHz
• Native DSD512
• FLAC
• WAV
• ALAC
• AIFF
• APE
• AAC
• MP3
• OGG

Whether your library consists of studio masters or carefully curated streaming playlists, the SP4000T reproduces every recording with extraordinary accuracy.

Premium Wireless Performance

Enjoy the convenience of wireless listening without compromising sound quality.

Features include:

• Bluetooth 5.2
• LDAC
• aptX HD
• LHDC
• Dual-band Wi-Fi
• USB DAC functionality
• USB-C connectivity
• Optical digital output

Designed Without Compromise

Machined from premium stainless steel, the SP4000T continues Astell&Kern’s iconic industrial design philosophy with striking geometric lines, exceptional craftsmanship and a precision-engineered volume wheel.

A 6-inch 2K touchscreen provides a beautifully responsive interface, while subtle illumination behind the vacuum tubes offers a visual reminder that genuine analogue technology is working beneath the surface.

Key Features

• Quad Raytheon JAN6418 genuine vacuum tubes
• Industry-first Triple Tube Mode
• Triple AMP System (Tube, Hybrid & OP AMP)
• Up to 54 unique analogue sound configurations
• Dual AK4191EQ + Dual AK4499EX flagship DAC architecture
• Balanced 4.4mm and 3.5mm outputs
• Up to 8Vrms balanced output
• Supports PCM 32-bit/768kHz and Native DSD512
• 256GB internal storage
• microSD expansion up to 1.5TB
• Bluetooth 5.2 with LDAC, aptX HD and LHDC
• Dual-band Wi-Fi
• 6-inch Full HD touchscreen
• USB DAC functionality
• OTA firmware updates

Why Buy the Astell&Kern SP4000T from Audio Concierge?

At Audio Concierge, we don’t simply sell premium audio products—we help you discover the perfect portable listening system.

Every customer benefits from independent advice, expert product knowledge and genuine after-sales support to ensure the SP4000T is perfectly matched with your headphones or in-ear monitors.

If you’re looking for one of the finest portable music players ever created, the Astell&Kern SP4000T sets a new benchmark for reference-quality portable audio.

Trade-In?	No, Yes
Enclosure Material	Stainless Steel