GZDtdsd B4 X - Portable Rechargeable 450mW

Feature: 1. Pretty Sounds: Independent op amp and power supply will reduce interaction as well as improving signal to noise ratio and sound quality. 2. Smart Designs: The power supply, electronic tubes, and operational amplifiers are all independently symmetrical. Also, the dual op amp parallel output power is higher. 3. Wide Matching: Comes with 2 kinds of interfaces, 3.5mm and 2.5mm, the stereo amp is compatible with various balance and standard headphone. 4. Better Safety: Has built in battery protection circuit as well, when the battery is fully charged, it will automatically shut down and the charging indicator will turn green. 5. Easy Carrying: Light in weight and compact in size, the vacuum tube headphone amplifier is very convenient to carry for outdoor use. Specification: Item Type: Headphone Amplifier Model: B4 X Material: Aluminium Alloy Input: 3.5mm Stereo Input Output: 2.5mm balanced output through BAL interface, and 3.5mm standard stereo interface output. Charging Voltage: 12.6V Battery: 1 x 1000mAh 12V lithium battery, shipped with built in battery. Charging Time: 2-2.5 hours full battery. Working Time: 4-4.5 Hours Output Power: 450mW Signal to Noise Ratio: 99dB Recommended Load Impedance: 16-400Q Package List: 1 x Headphone Amplifier 1 x Power Adapter 1 x Audio Cable 2 x Band 1 x User Manual Note: When using the headphone amplifier on your phone, if you hear some noise in your headphones, this could be the interference from the cell phone, such as WIFI or 4G signal, that interferes with the tube and makes the noise. This is normal. Because all tubes have a microphone effect. To avoid this, keep your phone away from the headphone amplifier.