Nux GP1 is a portable guitar plug-in amplifier that you are looking for.

You can play your electric guitar anytime, anywhere. You can adjust the gain and tone level according to your choice. The built-in aux input allows you to connect any media device and play along to songs or backing tracks. You can minimize the loud playing sessions to a self-intuitive interaction and output through headphones without disturbing your neighbourhood

It has three control knobs – Level, Tone and Gain.

The Level knob is simply your volume control knob which can be adjusted as per your preference.

The Tone knob is similar to your electric guitar speed knob which “opens” or “muffles” the sound as desired.

The Gain knob acts as the controller for the amount of overdrive this headphone amp can produce.