Features: This power amplifier can be connected with passive speaker to get powerful HiFi music. Dual classical 6J2 tubes gives you warm and powerful sound, removable design for convenient replacement and upgrade. Supports BT, RCA and 3.5mm stereo audio input, you can play the music on your computer, CD player, smartphone, tablet or other audio players freely. Adopts TPA3116 as the core chip, 1.2MHZ modulation frequency, less than 0.1% (10W) distortion, up to 50W + 50W dual-channel high-power output. The treble, bass and volume adjustment knobs allows you to modify the music sound according to your preferences. Compact size design, with all aluminum alloy shell, portable and durable.