1. Multifunction and easy control: The mixer collects sounds from multiple different sources (guitar, bass, and keyboard) at listening position or forwarding. Each channel of the linear mixer has an independent volume control, and each channel also features an independent input jack and volume control, along with a single output for the amplifier. It mixes multiple channels into one track, making it suitable for keyboards, small stage setups, drum kits, or submixes. 2. Low noise: The mini mixer delivers the sound quality at all output levels, operating extremely quietly while offering audio performance. Distortion and easy to set up, it is for quickly and effortlessly mixing 4line level signals. The 4channel mixer ensures the signal quality and integrity, even at peak levels, making it ideal for multikeyboard rigs. 3. Simple stereo/mono switch: The mixed sound is divided into channels. The input and output connections must use a 1/4' TRS stereo audio cable (the plug must be a stereo version—1/4' stereo audio cable from plug to plug, with TRS cable being the key point), and then press the switch button. The mono version mixes 6 mono signal inputs into 1 mono output (input and output connections use a 1/4' maletomale cable). Note: TRS cable is not included.