DC 12V VU Meter Driver Audio Level Indicator/Power Meter 10 LED Level Indicate Feature: 10-segment LM3915 level indicator board. The board has a first-level amplifier (using 741 single op amp), and there are two sets of high and low inputs. It can be used to indicate the output level of the front stage or power amplifier. Power supply: 12VDC. There are 11 LEDs in total, 3mm LEDs, 10 LEDs for level indication and 1 LED for power supply. The color matching default is: 7 green, 3 yellow, 1 red Specifications: Power supply: 12V150MA Input sensitivity: low input: 150mV to 6V rms (47K) High input: 1.5V to 60V rms (470K) Size: 35x70mm Weight: 20g Wiring instructions: There are 4 wires on the board, distinguished by color, Connected to the pre-stage or microphone amplifier: Red: connect the power supply 12V positive, black: connect the power supply 12V negative. Yellow: connect to the positive signal line, green: connect to the negative signal line (outer layer, shielding layer) Instructions for connecting to the speaker terminal: 1. The yellow wire needs to be soldered down and soldered to the HIGH position. 2. Connect the blue wire-the black terminal of the horn, and the yellow wire ---- the red terminal of the horn. 3. It should be noted that the power ground wire and signal ground wire of the panel power supply should be connected together. Package included: 1pcs*LM3915 10 LED Audio Level Indicator Assembled