The HV2405E integrated circuit is not very common these days. This circuit was found in the August 1998 issue of Electronics Now magazine. The current is a few tens of milliamps.
In the figure we have the typical circuit of a Baxandall tone control applied to an operational...
This circuit makes use of older operational amplifiers, but can be designed on the basis of modern...
This circuit that can be assembled in an “aspirin box” was found in the Radio Electronics magazine of...