Found in RCA documentation from the 90s, this bass and treble control uses an operational amplifier from the time that can still be found today.
Found in an Elektor from the 90s, this circuit is used with analog TV signals. The components are...
The circuit is from the 1994 National Semiconductor Linear Applications Handbook but can be...
The purpose of this PLL circuit that we found in the November 1986 Radio Electronics magazine is...