This high impedance headphone amplifier was found in American documentation from the 1990s. Any general-purpose FET can be used.
The coils determine the frequency of this oscillator that we found in the January 1996 issue of...
Found in a 1969 documentation, this neon lamp circuit may have the number of steps increased. The power...
The first transformer is a driver found on transistor radios and the second a small output...