Neewer Super Compact 4-Channel Stereo Headphone Amplifier with DC 12V Power Adapter for Sound Reinforcement, Studio, Stage, Choir, Personal Recording, Features Ultra Low Noise, Premium Sonic Quality : Amazon.ca: Musical Instruments, Stage
4 Channel Headphone Amp, Ultra Low Noise Super Compact Headphone Amplifier HA400 Monitor Distribution Flexible for Choir for Recording : Amazon.ca: Electronics
Headphone Amplifier, 4 Channels Metal Stereo Audio Amplifier with Power Adapter Portable Headphone Splitter for Studio and Stage : Amazon.ca: Electronics