The operational amplifier for this tone control found in a 1977 Signetics manual may be the 741. The power supply must be symmetrical and the signal cables short. The bass gain is 20 dB.
This simple circuit is from a Radio Electronics from July 1965. The circuit can be assembled with...
Found in the May 1975 issue of Radio Electronics magazine, this circuit turns on after a certain...
We found this circuit in a 1965 General Electric documentation. The circuit generates synchronized...