Preamp: This preamp board can condition the incoming audio signal before sending it to the power amplifier board Intelligent Design: The preamp module uses dual 5532 chips, which have good working stability and high efficiency Easy to Use: The preamp module is compatible with 2.54mm and 5.08mm connectors, and whose output is DC12V Good Control: The preamp module adopts continuous adjustment of treble, midrange, bass, and volume, it is very simple Easy Installation: This tone board comes with M3 mounting holes, which is easy to install and can be completed quickly in minutes Item Type: NE5532 Preamp Chip Model: NE5532x278M12x1 Input Voltage: DC 12-25V AC 9-18V Architecture: Dual 5532 High, Medium, and Low 3-stage continuously adjustable Features: DC12V output Input Interface: Approx. 2.54 mm / 0.10 inch interface, approx. 5.08 mm / 0.20 inch terminal Output Interface: Approx. 2.54 mm / 0.10 inch interface, approx. 5.08 mm / 0.20 inch terminal Adjustment Type: Treble + Midrange + Bass + Total Volume Mounting Holes: M3 (diameter: Approx. 3.3 mm / 0.13 inch) Material: PCB 1 x Volume Control Board 16 x Accessories