Simple but effective 2 Band Tone Control Circuit using transistor

Build this simple 2 band tone control Circuit using transistor with complete schematic and layout you can download.

Tone Control Circuit

Last time I posted a 2 band tone control project that used an opamp IC here.

This circuit uses a transistor instead of an IC. This design is based on my previous post here but I haven’t designed the PCB for it. The tone control design was for “Super Bass tone control” which has up to 16dB of bass gain.

simpe 2 band tone control circuit

The circuit is stereo so you do not need to build 2.


I used LTSpice for simulating this circuit. A bit of a challenge in using this simulation circuit is the lack of a potentiometer model.

As you can see on the simulation, it can boost 100hz bass frequency up to 16dB. You can further improve the bass frequency response by playing on the value of C5 and R8 on the simulation circuit.

PCB layout design

I used kicad for the PCB layout. I used 1 layer PCB so it will be easy to build

3D Render

The reason why I love to use KiCad is because it have built in 3d viewer and it is free. 🙂


You can download the PCB files on the download page. I only include the PDF file on the downloads. If you need the kicad file, you need to subscribe to my youtube channel first and send me a message through my facebook page.

Download page

Bill of material

C11uelectrolytic capacitor 25v
C21uelectrolytic capacitor 25v
C3100uelectrolytic capacitor 25v
C51uelectrolytic capacitor 25v
C61uelectrolytic capacitor 25v
C70.01uceramic or mylar capacitor
C80.1uceramic or mylar capacitor
C90.01uceramic or mylar capacitor
C100.1uceramic or mylar capacitor
C110.0022uceramic or mylar capacitor
C120.01uceramic or mylar capacitor
C130.0022uceramic or mylar capacitor
C140.01uceramic or mylar capacitor
C1510uceramic or mylar capacitor
C170.1uceramic or mylar capacitor
C180.1uceramic or mylar capacitor
C191uelectrolytic capacitor 25v
C201uelectrolytic capacitor 25v
C21100uelectrolytic capacitor 25v
J1input3pin JST connector
J2VDC2pin JST connector
J3output3pin JST connector
Q12N3904NPN Transistor
Q22N3904NPN Transistor
Q32N3904NPN Transistor
Q42N3904NPN Transistor
R1560k1/4W resistor
R2560k1/4W resistor
R35.6k1/4W resistor
R43301/4W resistor
R55.6k1/4W resistor
R63301/4W resistor
R715k1/4W resistor
R81k1/4W resistor
R915k1/4W resistor
R101k1/4W resistor
R1110k1/4W resistor
R1210k1/4W resistor
R1310k1/4W resistor
R1410k1/4W resistor
R1510k1/4W resistor
R1710k1/4W resistor
R19560k1/4W resistor
R20560k1/4W resistor
R2110k1/4W resistor
R2210k1/4W resistor
R231k1/4W resistor
R24560k1/4W resistor
R25560k1/4W resistor
RV1100kStereo Potentiometer
RV2100kStereo Potentiometer
RV3100kStereo Potentiometer

Design Reference:

The Baxandall Tone Control Circuit