Line Level Audio Attenuator Circuit. This project arose from the fact that i had too much gain in my audio system and i needed a practical solution without modifying the pcb circuit. Line level input r1 mic level output r2 ground input ground output r1 33 kohm r2 100 ohm circuit technical data.
47k ω resistor hot output hot pin 2 line level out 100 ω to microphone input low output low pin 3 47k ω resistor. Professional line level sometimes called 4dbu is around 1 75v peak to peak this is the signal level used by most outboard mixers and the level produced by many synthesizers drum machines and other electronic musical instruments. I d try to keep the input impedance of the divider at least 1 kω which is r1 r2.
Description of the circuit.
R1 of 2 kω and r2 of 1 kω would divide the input by 3 while maintaining a reasonable input impedance. To match the audio level use the resistor attenuator shown below. I am making a diy attenuator so that i can have a safety track for the audio in my video. The line level signals should be in 0 3 2v range to be suitable for amplifier s line level input.
