This common circuit using operational amplifiers was found in the 1993 issue of Radio Electronics Special Projects. The circuit is sandwiched between the pickup and the amplifier input.
This circuit, in addition to transforming a sinusoidal signal into a square, shifts its phase. The...
The transistors on this circuit can be the BC548. The circuit is from English documentation from...
In the figure we have three voltage doubler configurations that can be used in high and low...