This circuit was found in a documentation from 1948. There are 5 valves with push-pull output. The source uses a transformer, and the indicated application is with turntables.
This circuit makes use of a sensitive 5 mA reed-relay to be driven directly by a phototransistor. The...
This circuit was found in a 1967 RCA manual. The transistors are of the time. The adjustment is made to...
This powerful amplifier was part of commercial sound circuits from the 90s. The integrated circuit...