Pure vacuum tube integrated amplifier 
Handmade soldering, no PCB.
Convenient wireless Bluetooth transmission mode access audio source
Better APT-X Bluetooth Digital Audio Compression Algorithm
The voltage amplification stage and the push stage use the Dawning 12AX7 and 12AU7 vacuum tubes respectively
The front is powered independently by the US RCA 22ED4 rectifier
Left and right channels use two KT88 (EL34) vacuum tubes for AB1 push-pull power amplification
Triode and ultra-linear working modes are available
External power tube BIAS ADJ. adjustment and BIAS detection table function
High efficiency, low leakage magnetic toroidal power transformer and two EI type custom output transformers
Specification:
Rated output power: 21W + 21W (RMS Triode) 40W + 40W (RMS Ultra-Linear) 
Frequency Response: 10Hz ~ 50kHz (-3 dB) 
Total Harmonic Distortion: 1% (1kHz) 
SNR: 90 dB 
Input Sensitivity: 300 mV 
Input impedance: 100kΩ 
Output Impedance: 4Ω, 8Ω 
Use vacuum tube: 12AX7 × 1,12AU7 × 2, KT88 × 4 ,22DE4 x 1
Input terminals: 3 groups of RCA / Bluetooh
Volume: 360mm × 330mm × 180mm (W × D × H) 
Weight: 16.5kg 
Gross Weight: 19kg 
Maximum Consumption Power: 230W 
Power supply: AC 230V / 50Hz (± 10%)
Bluetooth: V4.0
Main Chip: CSR8670
Audio transmission system: SBC/AAC/APT-X
Transmission distance: 10M