This circuit has an accuracy of 1%. The components used must be precision as well. The input frequency range is 40 Hz to 10 kHz with the indicated components.
This basic tone control circuit employs a Philips NE5538 operational amplifier, but can be adapted to work...
This Siliconix circuit was found in a 1980s documentation. The coil consists of 18 turns of 22...
This circuit has a traditional configuration often found on this site. The transistor must be...