This circuit filters low frequency noise from the turntable motor. We found it in a 1989 documentation. The font doesn't have to be symmetrical, but it should have excellent filtering.
This circuit can produce signals up to 100 kHz depending on C1 and R1 adjustment. The output has a...
Found in Radio Electronics this circuit uses a fotodiac to drive a triac. The circuit can use...
This circuit was obtained in an American documentation translated in the 80's. The circuit can be...