We found this 6-tube amplifier in a 1947 publication. It is a Public Address amplifier with excellent performance using triodes on the output.
We found this circuit from a commercial megaphone in a Japanese publication in 1967. The circuit is...
This circuit was found in an Elektor from the 90s. The circuit is critical, requiring a very...
This circuit was found in a 1987 documentation but uses components quite common in the current...