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 circuit was found in English documentation from the 90's. Transistors are general purpose types....
This instrumentation circuit is from the June 1986 issue of Radio Electronics magazine. Equivalent...
This is an interesting idea that we found in the May 1971 issue of Radio Electronics magazine. It can...