I found tis circuit in na old documentation from 1958. The circuit uses germanium transistor availble that time and hard to obtain today. The circuit is indicated for phono applications using variable reluctance transducer.
This 1967 Electronics World circuit is suitable for frequencies up to 1 MHz. The setting applies...
This circuit was obtained from Maxim documentation. The circuit has 4.5 and 5.5V thresholds for...
This amplifier circuit for instrumentation was found in the manual of the used integrated circuit...