The circuit was constructed with the use of power audio amplifier LM380 in conjunction with the circuit that makes use of electronic soft switching and tone control.The circuit was constructed with the use of power audio amplifier LM380 in conjunction with the circuit that makes use of electronic soft switching and tone control.
http://www.zen22142.zen.co.uk/Circuits/Audio/2wamptc.htm
It seves the purpose of aligning an FM Stereo Modulator used in low power FM stereo transmitters. Two tone outputs are available, the low tone has a secondary output that is 180 degrees out of phase with the primary output.
http://www.solorb.com/elect/stereoosc/index.html
http://www.aaroncake.net/circuits/volume.htm
This simple tone control can be used in may audio applications. It can be added to amplifers, used as a stand alone control module, or even built into new and exciting instruments.
http://www.aaroncake.net/circuits/tone.htm
Simple add-on module Switchable "Control-flat" option.
http://www.redcircuits.com/Page67.htm