Quantity   Component name
1 × NE5532 Amplifier and Linear ICs / Operational Amplifiers
1 × BD139 NPN transistor
1 × BD140 PNP transistor
1 × 1N4148 Diode
1 × LM7805 Linear Voltage Regulators
1 × MH-M18 Integrated Bluetooth audio module
1 × HW-398 USB-PD sink module