This circuit was found in a 1969 Motorola documentation. The FET admits an equivalent. The circuit has high input impedance and is powered by voltages from 6 to 30 V.
The circuit we showed was obtained from our publication on relays and makes use of any...
This preamp with a transistor for turntables with crystal capsules was found in a Japanese...
The basic idea of this circuit is to convert the indication of a magnetic sensor to an audio tone...