We found this active crossover in a Radio Electronics magazine from June 1961. Note the different adjustment ranges. The signal must be applied to the amplifier input.
Using transistors at the time, this circuit was found in a 1967 Ferranti documentation. The...
These circuits were found in Exar documentation from the 90s. The circuits use both a small...
Found in Radio Electronics, this circuit is intended to activate the lighting system of garages...