This is a inexpensive high fidelity (hi-fi) tone control circuit designed just with two low cost transistors as the active components. The schematic is one channel (mono) tone control, build the similar circuit will make it become stereo channel.
This Hi-Fi tone control circuit can be operated with wide range supply voltage, 12V – 24V DC. Three potensiometers used for sound adjustment: volume level, bass and treble level.
Use good components (such as metalfilm resistors, MKM capacitors, tantalum capacitors, good cable quality) and stabilized/regulated power supply for better sound quality output, of course it will be need more cost. 🙂
The quality of components, cabling and power supply will affect the quality of the output.