Many typical active direct boxes can't handle the load of a battery-powered guitar or bass, which can get as hot as 7 volts. However, the Radial Engineering Pro48 is not only a great sounding active direct box, it's been optimized to produce maximum headroom while working within the limited current available from standard 48V phantom power. This makes the Pro48 ideal for use with acoustic instruments and electric bass guitar.The compact Pro48 is built road-ready with 14 gauge steel in our unique book-end design that provides protective zones around the switches and connectors. The internal welded I-beam construction assures outside stress will not torque the PC board thus assuring longer product life.FeaturesHigh-performance active direct boxIncreased dynamic range and headroom48V phantom-powered switching supplyIdeal for acoustic guitar and bassLED for when 48V phantom power is presentSpecificationsAudio Circuit Type: Proprietary analog circuit with low-noise op-ampFrequency Response: 20 Hz - 20 kHz (±1.5 dB)Dynamic Range: 99 dBTotal Harmonic Distortion: 0.001% @ 0 dBuIntermodulation Distortion: 0.002% @ 0 dBuPhase Deviation:+28° at 20 Hz+1° at 1 kHz-2° at 20 kHzInput Connector: 1/4"Input Impedance: 220 kΩEquivalent Input Noise (EIN): -86 dBuNoise: -82 dB below 0 dBuMaximum Input: +9 dBuOutput Connector: XLROutput Impedance: 600 ΩFeatures: Input pad, ground liftConstruction: 14-gauge steelPower: +48V phantom - proprietary digital switchingConditions: For use in dry locations only, 5-40°CDimensions (H x W x D): 1.75" x 2.75" x 4.25"Weight: 1.2 lbs (0.54 kg) Radial Engineering Pro48 Active Direct Box.