This 5-tube hi-fi amplifier was found in an American publication from 1947; The output is in class B and the circuit uses a source with transformer.
This filter with the 741 op amp was found in the February 1995 Electronics Now magazine. The power...
Suggested by an old American documentation the circuit below keeps a battery charged and at the...
Found in documentation from the 90s, this circuit was used in communications receivers of the...