Kicker 4 channel amp

Mini PAM8403 Digital Audio Amplifier Board 4 Channels 3W*4 DC 5V Stereo Sound AMP with Cable for Speaker

HA400 Stereo Audio Mixer Headphone Amplifier 4 Channel RCA Inputs Separate Volume Controls with Power Adapter US/EU

Mini Stereo Audio Mixer with 4-Channel RCA Inputs Separate Volume Controls

4 Channel Audio Mixer Portable Headphone Amp Lightweight Volume Adjustable Knob with 5V Power

UHF 4 Channels Wireless Guitar System Transmitter and Receiver 800MHz-900MHz Plug and Play

VU2 Digital Analog Dual VU Meter Audio Splitter Switcher Box Supports 4 Channels Gain Adjustment

1800W Peak Power HiFi Sound Amplifier Digital 4 Channel Audio Amplifier Bluetooth Karaoke Player FM Radio Support Remote Control

2000W 326BT 12V/110V Bluetooth 2.0 Channel Audio Power HiFi Amplifier Stereo AV Amp Speaker Support 4 Microphone with Remote

HA400 Ultra Low Noise Headphone Amplifier Ultra Compact 4 Channel Stereo Headphone Amplifier

Behringer Power Amplifier 4 Channel 75W 1U Size ATR Transient Technology EPQ304 Silver (Accelerated Response)