This is a very useful autotransformer circuit on the bench. We found it in the September 1970 Radio Elecronics magazine. The transformer must be according to what you want to feed at the output.
This circuit was found in a 1977 Radio Handbook. The ports used are CMOS like 4001 and the...
I found this Vox circuit or acoustic receiver as it was originally called, in a 1973 publication. The...
Found in RCA documentation from the 90s, this bass and treble control uses an operational...