CLASS A BOOST (Class A Boost) adopts a single end "Class A circuit" by a discreet transistor to boost high quality sound for any input signal. Provides a sharp and clean boost up to 20 db. In addition, it has a high S/N ratio and is designed to minimize noise so you can use it in a variety of situations. The overdrive sound provides punch and power and further aggressive crunches for distortion sound. The CLASS A BOOST also works well with all tube amplifiers to bring out sweet and fat tones. With the included 18V adapter, you can get the best headroom and punch. Adopts Discrete Class A FET Transistor Circuit Boost Instrument or Line Level Input Signals True Bypass with 18V Adapter Input Impedance: 500K ohms Max Input: 3.3Vp-p (+3.5dbm) Output Impedance: 150 ohms Max Output: 8.0V p-p (+11.2dbm) Gain Range: . 10. 5 (+20.4db) Frequency response: +0, -3db: 22Hz. 39KHz Consumption current: 48mA. Power supply: 18VDC@300mA (included); Size: 118(W) x 67(D) x 48(H)mm Weight: Approx. 0.2kg