Implementing a bass treble tone control circuit into a usb powered audio amplifier.

Discussion in 'The Projects Forum' started by Cas Lijnen, Mar 12, 2018.

  1. Cas Lijnen

    Thread Starter New Member

    Mar 12, 2018
    My question is: if it is possible to add the tone control circuit into the audio amplifier?

    If so I guess I'd need to implement two, one for the left channel and one for the right channel. And I could use a stereo potentiometer to control both of them. I would put one between C2 and VR1 and the other one between C3 and VR2.

    But here is the problem, I don't know if implementing these tone control circuits would mess up the rest of the circuit. Also maybe the values need to be changed? And i wonder if the spot where i'd put them is alright?
  2. crutschow


    Mar 14, 2008
    The impedances will interfere with the tone control operation.
    To minimize that, try reducing all the tone control resistors by a factor of 10 (including the pots) and increasing all the tone-control capacitors by the same factor.
    Eliminate R2 and R3 on the amp input.
    Increase C2 and C3 to 1μF (non-electrolytic).
    Increase the VR1 and VR2 pot size to 100kΩ (these should be audio pots, not linear pots).

    If the amp appears to have too much gain, add a resistor in series between each volume pot and the tone control.
    Start with about 50kΩ.

    So the signal path is now: PC output → cap (C2 or C3) → tone control →optional resistor → volume control (VR1 or VR2) → amp.

    You will need two stereo linear potentiometers, one for bass and one for treble.
    Last edited: Mar 12, 2018
    Cas Lijnen likes this.
  3. Cas Lijnen

    Thread Starter New Member

    Mar 12, 2018
    Thank you so much for the answer, i will try what you said.