One of the best tube amplifiers in the world! With small size and multi functions at affordable price, Dared MP-5BT tube amplifier combines the warmth of tube pre amplifier stage with the efficiency and power of solid state class AB amplifier, this structure ensures this amp will deliver natural, articulate sound.. Bluetooth(DARED BT 4.0) Pairing Guidance : After the first moible phone was paired up to this amplifier, it will mean this amplifier defaults to the first phone . If you want to switch to another phone, then the bluetooth of the first phone need to be switched off or you delete the amp's bluetooth from the setting of the first phone, then restart the amp, and finally try to pair up with the second phone within 5 minutes. Normally it just take less than 1 minuts to hook up. If you fail again, then restart the amp again, and try to hook up in 5 minutes again. Important Reminder: -- if you want to remove the cage, much care need to be taken when you try to loosen the screws holding the cage in place, or else the beautiful finish will be damaged. -- Better not remove the cage and just keep it as it is when you receive the amp. With the cage on , it will protect the tubes and your hands from touching the tubes carelessly when the amp is working. Specifications: Max. Power Output: 2x25W Frequency: 20-25kHZ S/N Ratio: 86dB Distortion: 0.1% Input Impedance: 100kΩ Output Impedance: 4Ω, 8Ω Max. Power Consumption: 110W Input: bluetooth,USB DAC, LINE Output: Speaker, Headphone,Stereo Preamp Voltage: AC100-120V/50-60Hz ,AC220-240V/50-60Hz Tubes: 6N1, 6N2, 6E2 Dimensions: 10.24*6.3*6.1 inch (LxWxH) Weight: 8.36lbs What are in the box: A pair of white cotton gloves A wiping cloth A power cable A nice real, long USB cable A nice manual A simply gorgeous bijou integrated tube amplifier.