This circuit was found in the March 1980 issue of Radio Electronics magazine. It is based on the newly released LH2400. The circuit must be powered by a symmetrical power supply.
This configuration was found in the Texas Instruments optoelectronics manual. PNP transistors...
These basic bass controls were obtained from an article in Electronics Now magazine in February 1995....
This circuit was obtained in a 1991 Electronics Handbook. The publication no longer exists, but...