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 was found in a 1967 General Electric documentation. The circuit generates signals...
This interesting effect circuit was found in a 1982 publication. The sequence of musical notes is...
This circuit is from a 1969 General Electric manual. The SCR may be the TIC106. Similar circuits...