The Radial Engineering ProRMP is a 100% passive Reamper. This means it does not require any external powering. The magic behind the ProRMP's great tone is a custom wound transformer that at once converts the balanced line level source to a hi-z output for your amp while also acting as an electrical isolator to eliminate troublesome ground loops that can often cause buzz and hum in the sound. Plug and play easy to use, the ProRMP connects from the recorder to your amp and effects units and does all the impedance matching for you. Just adjust the level to suit! Product Specifications: Audio Circuit Type: Passive, transformer isolated Frequency Response: 20Hz ~ 20KHz (+0/-1dB) Dynamic Range: >137dB Gain: >-10dB Total Harmonic Distortion: 0.003% Phase Deviation: 0.3° @ 100Hz; 5° @ 20Hz Input Impedance: 1600 Ohms Output Impedance: 1850 Ohms Common Mode Rejection Ratio: 100dB @ 60Hz (unbalanced source) Equivalent Input Noise: >-98dBu Noise plus gain Noise: -111dBu Maximum Input: >+26dBu Features: Input pad, 180° polarity reverse, Ground lift Input Connectors: XLR Output Connectors: 1/4" Construction: 14-gauge steel chassis and outer shell Size (L x W x D): 3.3" x 5.0" x 2" (84 x 127 x 48mm) Weight: 1.55 lbs (720 g) Power: Passive, no power required Conditions: For use in dry locations only between 5°C and 40°C