This 2-tube amplifier was found in a Japanese publication of 1964. The circuit has excellent sound quality. The power supply is not given and must provide a voltage of 300 V.
This low frequency doubler requires a 50 mV signal at the input. The circuit is from an old...
We found this circuit in GE's 1977 transistors manual. Transistors admit equivalents according to the...
This transistor tester circuit has the advantage of using a constant current source in the tests....