Quantity   Component name
1 × 4mm Plywood
1 × Arduino UNO
4 × 10Kohm, linear mono potentiomenter attached to the analog inputs of the arduino
2 × 47Kohm logarithmic mono potentiomenter Line volume and speaker volume
2 × Mini switch Display on/of, device on/off
1 × pocket calculator
1 × 9V battery
1 × 1W x 2 amplifier
1 × 1 LED
1 × 1 x 12 Ohm speaker The speaker was a headphone capsule in its previous life
1 × Headphone jack