The Saramonic SR-PAX1 Two-Channel Audio Mixer, Preamp, Microphone Adapter  a compact, two-channel active audio mixer with pre-amplifier and phantom power that is designed for DSLR cameras and camcorders. It can be used to record professional-quality audio from two independent sources and mix them into your camera simultaneously.

Saramonic SR-PAX1 attaches to the base of a camera, and a threaded socket on its base allows for mounting on a tripod or case. The two-channel audio mixer features two XLR inputs, two 3.5mm TRS inputs, and two 1/4″ inputs with a 3.5mm TRS output jack. The input levels of each channel can be controlled with the two gain-control knobs. In addition, a phone jack allows you to monitor the audio in real time.