This is the 1968 MR480 commercial cassette recorder circuit. The circuit was fully transistorized and powered by 4 large batteries. We found the diagram in a Japanese documentation of the time.
The LM380 is not a modern component and in some cases not easy to find. But if you have one you...
We found this circuit in the June 1992 issue of Radio Electronics magazine. The sensor is a common...
I found this circuit in a documentation about thyristors from the 70s. The circuit uses a diac...