Let's build a very simple amplifier circuit to drive a speaker

Source: Hackaweek

  1. Breadboard, etc.
  2. Power supply or 9 volt battery.
  3. Capacitors 0.01 uf (103), 0.047 uf (473) (see Capacitor Code Chart or Capictor Codes
  4. Electrolytic Capacitors 10uf, 100uf, 220uf
  5. Resistor 10 ohm
  6. Variable Resistor10k ohm
  7. Jack and Plug
  8. 386 amplifier chip

Experiments: change the capacitor between pins 1 and 8
Add a bass amplifying circuit by feeding some lower frequency signal back through the amp