QCC3031 wireless Bluetooth 5.0 core support aptX and aptX-HD, Streaming range up to 39ft(12m), With Bluetooth and AUX selector, no pop when Bluetooth connecting; 50W RMS X 2 power output(4 ohms, 20 Hz - 20 kHz, 0.04% THD), built-in speakers protection circuit, best for outdoor/ bookshelf/ computer/ desktop /ceiling /floor standing speakers, can use iPod, Phone, MP3 players, TV, Echo Dot, CD players, or Streaming Media players as input; Adopt 2 x 6A2 tubes to get clear audio sound, tubes can be replaced by JAN 5654W, 6K4, 6J1, GE5654, 6AK5, 6ж1П, 6BC5, 403A/B, EF40, EF95 and so on, with a headphone output for 16-64ohm headphones; Small simple compact design but practical and powerful, Hi-Fi Bluetooth amplifier receiver exclusively designed for the customers who pursue HiFi sound; Power amp + Headphone amp, perfectly suited for your desktop or a smaller space in your home or office, digital amplifier is easy to connect to your audio system with no software to install or settings to change.