Burst Electronics AS-4X1 4x1 Stereo Audio Switcher The AS-4X1 is a four stereo input, one stereo output audio switcher. The AS-4X1 includes an internal monitor amp and speaker. The monitor amp can drive external headphones or stereo speakers. It also features a peak LED indicator for each channel to guard against input overload. The 50kHz bandwidth and 85dB S/N assures clean audio. The inputs and outputs are unbalanced line level type with phono (RCA) connectors. RS-232 remote control is optional. DC powered for field applications.