The design begins with standard ¼ instrument input with a thru-put to feed your tuner or your on-stage amp. The ultra-quiet active circuit at once converts the signal from high to low impedance to reduce susceptibility to noise. The signal is then buffered and balanced for long cable runs to the PA system. 48 volt phantom provides the power, so the SB-1 does not require batteries or external supply to make it work. You simply plug in and you are ready to go! Features Active direct box for acoustic and passive bass Ultra compact to fit in your guitar case Plug & play easy to use feature set 48V phantom powered, no batteries needed! Specifications Audio circuit type: Active Buffer with Phase Splitter Number of channels: 1 Frequency response: 20Hz to 20KHz Dynamic range: >100dB Gain: +1.3dBu/+4.4dB Clip Level: +3.3dBu/+12.3dBu Total harmonic distortion: <0.006% Intermodulation Distortion: <0.01% Phase Deviation: 25/12° Maximum Input Impedance: 800K/23K Output Impedance: 330 Ohms Equivalent Input Noise: -101dBu Noise: -97dBu Maximum Input: +2dBu/+8dBu Input Connectors: 1/4 Output Connectors: XLR Construction: 16 gauge steel chassis & outer shell Size (L x W x D): 4.5 x 1,85 x 1.35 (114mm x 47mm x 34mm) Weight: 0.55 lbs (250 grams) Shipping size (L x W x D): 8 x 5 x 3 (203mm x 127mm x 76mm) Shipping weight: 0.8 lbs (365 grams) Power: 48V phantom power, 5mA Conditions: For use in dry locations only between 5°C and 40°C Warranty: Radial 3-year, transferable