Feature: 1. POWER SUPPLY METHOD: The circuit is powered by DC 9‑12V, using original IC, very easy to use. Each board is tested and adjusted by our professional test bench. 2. PROFESSIONAL VU: Use professional sound VU driver IC, the small pointer of this IC contains dynamic compression circuitry, logarithmic output characteristics to avoid the pointer going too big when it bottoms out. 3. MUTE FUNCTION: The IC has a mute function. The mute function pin will be at low level at the moment of power on, which can avoid touching the bottom of the pointer when powering on. The pointer will oscillate a small amount to conform to the power on habit. 4. SWING ADJUSTMENT: In addition to adjusting the load potentiometer, swing adjustment can also be made through the input voltage divider circuit. 5. BACKLIGHT: The brightness of the backlight can be realized by adjusting the resistor values of R9 and R10. The electrical parameters through the backlight can be easily calculated according to Ohm's law. Specification: Item Type: VU Meter Material: PCB Specification: 500μA Meter Head DC Internal Resistance: 1K (MF47 Pointer Multimeter Test); 630Ω Driver Board Voltage: 9‑12V. Package List: 2 x VU Meter1 x Driver Board Note: 1. Before use, make sure the pointer is aligned with the 0 point. If there is deviation, use a screwdriver to adjust the pointer to 0.2.The backlight is designed for 9‑12 V. If the backlight brightness meets the requirements, lowering the backlight operating voltage can greatly extend the life of the backlight. 9V is recommended.