This 4-tube amplifier with 6W of output was found in an American manual from 1947. The sound quality is excellent.
This circuit is from a 90s Popular Electronics. It appears elsewhere on this site. Q1 can be any...
This circuit works as a booster operating with signals from 1 to 30MHz. The gain is between 1 and...
This timer circuit was found in a 1980s American documentation. Transistors and SCR support modern...