This high impedance circuit was found in 1967 documentation by Ferranti. The original operational amplifier is from that time. The circuit can be implemented with modern equivalents.
Originally this piezoelectric microphone preamp was designed to be built-in, but given the use of a...
This is the traditional configuration of Baxandall bass and treble control, using passive...
We found this circuit in an American publication from the 1990s. The triac must be equipped with a heat...