Simple Mini Guitar Practice Amp

Looking at the circuit diagram, it is simple enough to understand how this tiny circuitry provides an amplifier suitable for guitar practicing.
List of components used as follows:

a) LM386
b) Electrolyte capacitors – 4.7uF, 100uF, 10uF ( prefer if Varicap), 470uF
c) Mono Jack (J1 and J2)
d) 9V battery
e) A couple of wires
f) Breadboard
g) Toggle Switch (S1)

However there are still more rooms for improvement i.e. additional features such as external power adaptor (if you runs out of battery during practice), one or two band EQ, Variable gain control instead of fix gain ( 20/200), buit-in guitar tuner, effect, . Hope to build this amp soon.