When Hifiman introduced its first Electrostatic Headphone, Jade, in 2008, it quickly became a favourite of audiophiles and music lovers who fell in love with its natural and expansive soundfield. Key Features Nano-particle coated diaphragm providing an extremely high-frequency response and an excellent musical reproduction ability High resolving audio and extremely high-frequency range allows the sound-stage to be dramatically open and expansive compared to a traditional "moving coil" type headphone A single crystal copper wire with gold-plated plug for lossless signal transmission Nanometer think dust cover helps prevent dust and other pollutants settling and avoiding ensuing distortion caused by electrostatic dust Housing from ABS and a steel frame composed of a stainless-steel honeycomb mesh for the anode casing. The honeycomb mesh can protect the headphone from airflow vibrations assuring that the sound reduction remains true and accurate Operation amplifier and a hybrid discrete component design TI Texas high precision dual op-amp OPA2107AP for signal pre-amplification Discrete transistor Cascode MOSFET powering the balanced output amplification High voltage power supply using an independent power supply regulator PCB layout optimization to reduce interference hum and allow for a more transparent sound Made of aviation grade aluminium alloy XLR balanced audio input and RCA source inputs Equipped with two headphone output ports 21 level volume control to allow for precision volume control AC 115V / 230V power selector Electrostatic Speed and Definition Reach from the deepest lows all the way to 90LHz. HiFiMan's oval-shaped earcups provide the maximum diaphragm size for deep, resonant bass response. Open-Back Design An expanded, more intimately enveloping soundstage with natural sonics that place the listener in the best seat in the house. Construction The Jade II Headphone is light, weighing only 265g. Combination of lightweight aluminium alloy construction, padded earcups, and a hybrid headband design ensures a comfortable fit, even for extended periods of time. Frequency Response: 7Hz-90kHz Bias Voltage: 500V-650V Headphone Weight: 365g (12.9oz) Amplifier Weight: 6.5kg (14.3lb) Amplifier Dimensions: 276 x 270 x 116mm (10.9" x 10.6" x 4.6")