HiFi VU Meter + Driver Board kit VU Meter DB Meter with Backlight Audio Level Amp Driver Board Home Audio HiFi Accessories

Good responsiveness to signal RMS. I had hoped the meters were a bit larger.

First, these are great little units. Second, these are VU METERS! A VU meter is designed and intended for LOW signal levels. a small signal of about .3 volts is ZERO db on these meters, and about 3.25 volts for FULL scale. This is a normal case for a true VU meter.That is why these little gems come with the board, it provides a method to connect the VU meters to a higher level signal source, such as a pre-amp output, or standard line level signal source between audio components.The pots are 25 turn, so you can have very fine adjustment resolution to match the meter with your signal levels.It is VERY important that you understand the input to this board is intended to have a standard ground referenced set of signals going to the left and right inputs. This is the case with audio components interconnections, and pre-amplifier outputs that feed INTO power amplifiers. THIS IS NOT so common with amplifier OUTPUTS that feed to speakers. MANY amplifiers have differential outputs that drive both the positive and negative amplifier to speaker connections so all the speaker connections are driven and NOT grounded, and MAY OR MAY NOT be ground referenced even.WARNING: If you MUST connect this to amplifier speaker outputs, FOLLOW THE NEXT STEPS AS APPROPRIATE FOR YOUR Amplifier CAREFULLY!Amplifier outputs and connections to this board.1. - Amplifier with a fully ground referenced output the the speakers, only the positive amplifier output driven. - Connect the Right positive Speaker out from the amplifier to the RIGHT signal input on the board. Connect the LEFT in a similar manner. Connect the common input to either the left or right common (-) ground connection.2. - Amplifier with a ground referenced bi-polar output, both the positive and negative speaker outputs are driven, in relation to ground, being driven in opposite polarities from each other. - Connect the Right positive Speaker out from the amplifier to the RIGHT signal input on the board. Connect the LEFT in a similar manner. DO NOT connect the common input to a speaker output connection or you will likely destroy your amplifier! Connect the common input to either the grounded common point on your amplifier, this may be hard to determine, you may need assistance of someone familiar with your amplifier, or additional support from the amplifier vendor.3 - Amplifier with isolated outputs, not referenced to ground in any way. - DO NOT USE THIS CONNECTED TO THE SPEAKER OUTPUT AS DAMAGED WILL LIKELY RESULT.