- Function and purpose A small audio amplifier circuit using a NE5532 op-amp to boost low volume signals for headphones. - Key specifications Power supply: DC 9-19 V Amplifier chip: NE5532 op-amp Gain: 10x (20 dB) Output: front 3.5 mm headphone jack Application: suitable for amplifying small audio signals from your device - Benefits Improves listening level for headphones when the source output is quiet Simple integration to add standalone amplification to audio sources Uses a standard 3.5 mm headphone interface for easy connection - Use scenarios Scenario 1: A smartphone, portable player, or computer with low volume. Connect to the module and listen through headphones at a comfortable level Scenario 2: DIY audio projects that require a dedicated small-signal headphone amplifier Scenario 3: Educational or testing setups to monitor low amplitude audio signals with headphones