This circuit is from an English documentation from 1969. The circuit can be designed based on modern equivalent transistors. Diodes are general purpose types.
This circuit was found in Radio Electronics from the 90s. The transistor is for general use. The...
This preamplifier is intended for the use with magnetic pick-ups. Power supply must have voltages...
This active crossover filter was obtained from the component manual used. Below is the performance...