This high input impedance tone control circuit was found in American documentation from the 1980s. Equivalent operational amplifiers and FTEs can be used.
This circuit was found in an old 1980s valve documentation. The circuit can directly replace a...
This circuit is from an 80's component manual. However, the circuit may be of a modern equivalent...
Found in an Electronic Design from the 90s, this circuit makes use of a PLL CMOS. Values for...