Quantity   Component name
2 × TL074 Amplifier and Linear ICs / Operational Amplifiers
16 × Resistance 10k (audio amplification)
4 × Resistance 330 (audio amplification)
4 × Potentiometer 10k (audio amplification: gain control)
4 × Capacitor 2.2uF (audio amplification)
4 × Capacitor 1.0 uF (audio amplification)
1 × Nokia LCD screen
4 × Condenser electret microphones
1 × Beaglebone Black board