SPECIFICATIONS

Product Introduction:
This VU level meter driver board is designed and manufactured using LMC660 and LM358 chips, making it very suitable for use as an audio accessory.
This product uses professional circuit design and high-quality integrated circuit chip components, which have excellent performance and excellent repeatability. The performance is stable and reliable, and the actual use effect is very good. It is recommended to use a single power supply of 7 to 15V DC for power supply, without the need for voltage stabilization. The current consumption, including the volume meter, is less than 10mA. The design of the volume meter has a full range of 500uA, but due to the large output current and wide working range of LM358, it is compatible with most volume meters.

Parameter:
Single power supply: DC 7-15V
Dimensions: 73.5x37.5mm
Installation hole size: 66x31mm

Function Description:
1. Use a single power source for power supply. (Recommended 6-15V).
2. Reduce the number of adjustments, improve repeatability, and ensure that anyone can easily operate.
When using a 1Vrms sine wave, make the VU meter read 0dB.
4. With reasonable accuracy and repeatability, only one circuit board is needed to drive the volume meters for the left and right channels.
instructions:
How to adjust the volume gauge
1. Only adjust the volume gauge. Mechanical pointer zeroing
Not only VU meters, but also all pointer type ammeters, voltmeters, and power meters have a screw for zero adjustment. It can be adjusted with a straight screwdriver. When adjusting, do not connect any devices to the instrument, place it horizontally, and then rotate this screw to reset the instrument to zero. When the environment is relatively dry and the humidity is low, static electricity will be generated between the instrument pointer and the transparent plastic
Force causes the inability to adjust the zero point. In this case, static electricity can be eliminated by wiping the plastic part with a cloth soaked in diluted soapy water.
[Zero position adjustment]
1. Connect the VU meter to the corresponding terminal on the circuit board and provide a suitable DC power supply for the VU meter driver circuit, with an output voltage between 7V-12V.
2. Connect the input of preamplifiers, computers, etc. Please perform this operation in a state without audio signal output or in a silent state.
3. If the VU meter pointer swings in the positive direction at this time, adjust VR3 (VR4) to make the pointer swing to zero position.
Sensitivity adjustment
1. Connect a computer or laptop, tablet or phone for adjustment
You can choose the relevant signal generator software, start it up, and output waveforms in "sine wave", "1kHz", and "0dB" formats. It is very convenient to use the test signal generation software "WaveGene" when making adjustments on Windows PC.
At this point, adjust VR1 (VR2) to adjust the VU table deviation to "OVU".
*This circuit does not strictly follow the "ANSI C16.5-1942" or "BS6840" standards, so there is no need to strictly follow this step. You can adjust according to the music you are listening to. It is recommended to set WaveGene to "0dB" so that the header pointer reaches the "+3" position.
2. Adjust using CD player, card holder, digital player, etc
If you have an audio test CD, please adjust it using "sine wave", "1kHz", and "0dB" using the same method as using a computer. The card holder should use a specially recorded audio test tape, and the digital player can play corresponding test audio files, such as MP3, WAV, etc., at least fixed audio signals. Input the left and right channels separately, adjust the potentiometers VR1 and VR2 to make the left and right meter heads indicate the same.
3. Use a signal generator for adjustment.
Select sine wave output with a frequency of 1KHZ and an output voltage of 1V. Connect it to the input terminal of the driver board and adjust the potentiometers VR1 and VR2 to make the pointer at the+3 position.

Package Include:
1X driver module