The block is the 4rd order Butterworth low pass filter with cut-off frequency adjustment. It is based on the two amplifiers with feedback and has differential input and output. There are two modes for ...

The cell is based on 3rd order Butterworth low-pass filter (LPF) with cut-of frequency adjustment in a wide range. There are 2 modes for cut-off frequency programming: manual and automatically. The ...

The cap in question is part of the guitar’s tone circuit, which along with a potentiometer forms a variable low-pass filter. A rich folklore has developed over the years around these circuits ...