Buffer 4049 (CB26316E)

The purpose of this circuit found in a 1990s Popular Electronics is to increase the current capability of CMOS stages.

Baxandall tone control (CB20804E)
In the figure we have the typical circuit of a Baxandall tone control applied to an operational...
Instrumentation Amplifier (CB4928E)
This circuit makes use of older operational amplifiers, but can be designed on the basis of modern...
Hearing Aid Amplifier (CB22566E)
This circuit that can be assembled in an “aspirin box” was found in the Radio Electronics magazine of...