I have the following schematic that is supposed to rectify the signal going to a VU meter and also trim it, so the user can adjust the position of "0dB".
What I don't understand is why and how the resistor is connected in that way, shorting legs 2 and 3. Is this working as a simple voltage divider? Or just a rheostat? How does it work and how does this trim the actual display?
The schematic is preceeded with a buffering op-amp.