If you are looking for a mic preamp with bass and treble control, you may consider this one. I designed it for my future mixer build. I am planning to build one someday when I am not too busy.
ABOUT THE CIRCUIT
The circuit is only on design stage, not yet done any prototype but it is working on my simulation. This is an improved version of the preamp on my audio mixer design I posted.
The rolloff on the 10k-20kHz range is caused by the capacitor C8. This is done to make sure the system will not allow any radio frequency to pass especially AM radio signals. If you want that roll-off to be more aggressive, you can increase it. Treble frequency is set by C3 and C4 while C2 is for setting the bass frequency. Increasing those capacitor values will decrease the frequency. For instance you want the bass to have more boost on the lower end frequency, just increase the value of C2.
Gain is set by R1, if you want more gain, increase R1 value. Potentiometer used are 100k, using 50k or lower will decrease the boost and cut range by around 3dB.
Simulation Results
All range: bass and treble at 0%, 50% and 100%
Bass control (0%-100% at 10% increment)
Treble control (0%-100% at 10% increment)
