Found in RCA documentation from the 90s, this bass and treble control uses an operational amplifier from the time that can still be found today.
This circuit is from a publication from the 50's. Inductive components are critical, and...
This simple two-transistor circuit used transistors from the 60s, having been found in a...
This circuit uses an oscillator that generates a signal of approximately 1450 kHz to test...