Single-supply power supply, tone board with fever- op amp AD828, technology, small size design, AC and DC. The potentiometer separate version is easy to install, is not limited by the spacing of the cabinet, and the shielded is linked, so there is no interference problem. Both op amps feature -plated round-hole socket. If the AD828 is not hot enough, it is easy to replace the better op amp chip. color: red material: plastic Potentiometer fixed version Potentiometer split version Potentiometer spacing: 25mm Note: The separated version of the potentiometer cable (the two wires of the same potentiometer) cannot be exchanged at will, otherwise it will work abnormally. The 4 potentiometers of the separate version may be shipped when they are shipped . Go back and move on. Working voltage: AC 3V-16V DC 5V-24V Board size: 100mm X 45mm (without potentiometer protrusion) Overall height of the board: 23mm or so 4 potentiometer spacing: 25mm (potentiometer fixed version) Package Contents:1 x Stereo Preamp Amplifier Board Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.