Features Dual Channel Design: This headphone amplifier board adopts dual channel design, OP AMP is compatible with multiple specifications of dual OP AMPs. Meet Different Needs: There are different OP AMPs to choose from, you can choose according to your own preferences. Exquisite Workmanship: Headphone amplifier board using fine workmanship, has small size, can be more suitable for various situations. Premium PCB Board: Good quality PCB materials, the headphone amplifier board with reliability and miniaturization, good maintenance and interchangeability. Support AC Or DC Input: This headphone amplifier board is a single power supply 47 AMP board, supply voltage support AC 6‑18V or DC 9‑24V. Specification: Item Type: Headphone Amplifier Board Material: PCB Input Voltage: AC 6-18V or DC 9-24V Package List: 1 x Headphone Amplifier Board Note: Pay attention to correct operation. Package List 1 x Headphone Amplifier Board