Staying true to philosophy of delivering original audio experiences without compromise, Astell&Kern strives to design portable music players that reach beyond the capabilities of a standard playback device to enhance the listener’s music enjoyment. The SP2000T combines the OP AMP configuration of SP2000 — the culmination of Astell&Kern's finest audio technology — with a nostalgic vacuum TUBE AMP, adding a vintage feel to the portable player. A&ultima SP2000T is the Ingenious New Solution. The Triple Amp System Takes Acoustics to a New Level. Vacuum Tube Amplifier is compatible with 2.5 mm, 3.5 mm and 4.4 mm output jacks. Equipped with ESS ES9068AS QUAD-DAC, for balanced, ultra detailed sound. TERATON ALPHA - Astell&Kern's Ultimate Sound Solution. ReplayGain Function to Maintain Consistent Playback Levels between Tracks. Dual-Band Wi-fi Support for Uninterrupted Wireless Connection and Improved Compatibility. Internal Mechanical Design to Minimize Noise.