An Electric Guitar Amplifier to XLR Audio output is explained in this amplifier circuit video. The Pickups on Guitar converts the string vibration into electric signal Vin that is then applied as the single-ended input to the first op amp stage in this circuit. This first operational amplifier combined with capacitors, resistors and a potentiometer constructs a non-inverting variable gain high-pass amplifier to minimize the unwanted DC offset of Op Amp and undesired low frequencies below say 100 or 50 Hz. The second op amp stage is cascaded at the output of the first stage and acts as an inverting amplifier with a constant gain of negative one to generate the differential output voltage so that the overall amplifier operates as a single-ended to differential programmable gain amplifier for electronic guitar and other audio instruments if need be. A combination of Kirchhoff Circuit Laws including KCL (current law) at negative input terminals of the two OpAmps and also Virtual short of the op amps enforced by negative feedback are used to compute the variable gain of the electric guitar amplifier that can vary from 6dB to ~40dB in this design.
1 апр 2024