Feature:1. Tone Control: With this pre amplifier, you can conveniently control treble, medium, bass and total volume.2. Broad Range: Enables 2020KHz wide frequency, and the tone control board also allows for easy adjustment.3. Simple Using: Supports DC 1225V and AC 918V input, and the installation is simple and quick to complete.4. Smart Design: Through exquisite workmanship, ensures quick cooling and stable long working hours as well.5. Stable Works: Uses 1.6mm thick board and whole process of spraying tin, energy saving and very efficient.Specification:Item Type: Pre Amplifier Material: PCBInput Voltage: DC 12-25V AC 9-18V. Structure: High, middle and low 3 sections continuously adjustable. Frequency Range: 20-20KHzFeatures: DC12V output. Input Interface: Approx. 54mm / 2.13in interface, approx. 5.08mm / 0.2in terminal. Output Interface: Approx. 2.54mm / 0.1in interface, approx. 5.08mm / 0.2in terminal. Adjustment Type: Treble + medium + bass + total volume. Installation: Mounting hole M3 (diameter approx. 3.3mm / 0.13in). .Package List:1 x Pre AmplifierNote:Don't overload.