【Stereo/Mono Operation】Stereo version: You must use the 1/4” TRS stereo audio cable male to male connectors for input and output connection (1/4" Male to Male Stereo Audio Cable (TRS Cable) is the key point). Mono version: Mixes down 4 mono signal inputs into 1 mono signal output (1/4” TS male to male connectors for input and output connection). TRS/TS cable is not included in package 【Compact Format】A heavy duty metal enclosure construction stereo mixer and the knobs have firm adjustment. There is a simple LED when 4 channel mixer is powered on. Its small size fits perfectly on top of your keyboard, allowing quick and convenient adjustments to monitor mix. 【Simple Controls】Audio mixer collecting the sounds from many different sources (microphones, guitars, bass and keyboards.) into one listening place for monitoring or routing. Each channel on the line mixer has an independent volume control separate input plugs and volume controls for each channel with one single output for an amplifier. 【Multifunctionality for a Simplified Setup】The line mixer is ideal for multikeyboard rigs and recording where several channels need to be mixed down to one track. It's perfect for your keyboards, small-stage setups, drum kits, or submixing before going to the main mixer. Modern design looks great on any desktop and large controls are easy to use and low-profile to avoid snagging on wires, clothes, etc. 【Low-Noise 4-Channel Line Mixer】 Mini audio mixer yields the highest sonic quality at all output levels, boasting ultra low-noise operational for outstanding audio performance. No distortion and easy to set up, perfect for mixing 4 line level signals quickly and without complications. 4-Channel mixer produces highest signal quality even at highest levels, in highest signal integrity.