Astell & Kern presents high-resolution music enthusiasts with quad-tube A&ultima SP4000T flagship digital audio player

Astell & Kern has unveiled the quad-tube A&ultima SP4000T flagship digital audio player, which will have its global debut at the High End Show Vienna 2026 on June 4, 2026.

The DAP is powered by an octa-core CPU running Android 15, with 256 GB of internal storage expandable up to 1.5 TB using microSD cards and a 6-inch Full HD touchscreen. It also features dual-band 802.11ax Wi-Fi and Bluetooth 5.2 connectivity, and can be used as a USB DAC with computers.

Audio is processed by dual AKM4191EQ digital signal processors and dual AKM4499EX DACs coupled with four Raytheon JAN6418 vacuum tubes that recreate the warmth of desktop tube amplifier decks. The tubes can be operated in Triode, Pentode, and Ultra Linear modes along with fine-tuning of other audio processing settings to bring out the sound characteristics favored by each user.

The resulting audio has a frequency response of ±0.006dB at 20Hz to 20kHz and ±0.06dB at 20Hz to 70kHz, a THD of less than 0.0006%, and an SNR of under 124dB. The DAP supports 3.5 mm unbalanced and 4.4 mm balanced wired headphones as well as the aptX HD, LDAC, LHDC, SBC, and AAC audio codecs for wireless headphones.

The player supports DSD512 and PCM 768kHz lossless music streams and can restore lost harmonics in compressed music streams using VSE (Virtual Sound Extender).

The DAP can run up to 10 hours on its 7,450 mAh battery between charges, which take five hours according to the company.

The A&ultima SP4000T DAP in copper or stainless steel will likely be priced above the SP4000's entry-level price of $3,900. Readers who can only dream of spending that much might look into a more affordable DAP.