Using a tunnel diode, this circuit was found in a 1966 American publication. The circuit is for signals sampled at a speed of 8,000 sps.
Circuits like this one, using the LM386 audio amplifier, are available from other sources in this...
This bass and treble control only attenuates the corresponding signals, requiring further...
Using a large inductance, this circuit was found in a Popular Electronics from the 90s. The...