Pre Tone Control Circuit (Transistor)

Notes:
Based on the classic Baxendall tone control circuit, this provides a maximum cut and boost of around 10dB at 10K and 50Hz. As the controls are passive, the last transistor provides a slight boost. The output is designed to feed an amplifier with input impedance of 10k to 250k. Both tone controls should be linear potentiometers.Source : http://www.mitedu.freeserve.co.uk/Circuits/Audio/t-ctrl.htm