This old fashioned transistor amplifier was found in a publication of the year 1958. Transformer are the critical components in the circuit and power comes from 6 D cells.
This circuit was found in an English magazine from 1976. The transistors can be the BC548. The...
This is an improvement on the previous circuit with a preamplification stage. The circuit is from...
We found this circuit in a 1974 integrated circuit manual. Operational amplifiers can be of...