Features DUAL CHANNEL: Adopt dual channel design, OP AMP is compatible with multiple specifications of dual OP AMPs SMALL AND FINE: Headphone amplifier board using fine workmanship, has small size, can be more suitable for various situations CHANGEABLE OP AMPs: There are different OP AMPs to choose from, you can choose according to your own preferences SUPPORT AC OR DC INPUT: This is a single power supply 47 AMP board, supply voltage support AC 6‑18V or DC 9‑24V EXCELLENT PCB BOARD: Good quality PCB materials, with reliability and miniaturization, good maintenance and interchangeability 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