Pre-Amplifier 4 is easy to build and provides Active Volume, Bass and Treble Control.

The volume control has a natural logarithmic adjustment scale, even though a linear potentiometer is used.

Usage examples are DIY Arduino Radios, Active Speakers, Instrument amplifiers or any other project where you want to add Treble, Bass and Volume control. You can also use it to extend an existing product (Active Speakers, Headphone Amps) with Treble and Bass control.

Easy to power since it has been designed to accept a wide array of voltage from single supply power supplies. If built with a TL972 Op Amp it can accept down to 2.7V. Works well with 5V USB, Powerbanks, Batteries (e.g 9V, 2xAA, CR2032, ...), or any other power source within spec of the Op Amp used.

Complete details and instructions can be found at: https://www.protoriam.com/preamp4/index.html