We found this circuit for musical instruments in the March 1992 Radio Electronics magazine. The circuit has outputs according to the desired scale from a crystal oscillator at the indicated frequency.
This power supply makes use of a capacitance multiplier. C2 can be 100 uF which with the action of...
This circuit, which appears in other applications on this site, was taken from a 2000...
Mouser Electronics is already providing new MOSFETs EF SIHx28N60EF of Vishay series for voltages...