Just got one of these. Behringer MX882 . It and the triple priced Rane device it is patterned after have been called the swiss army knife of audio. You can put a stereo signal at the input and send a mono mix or either side out to 6 level controlled outputs. You can input 8 channels and mix the main output. You can use any of the 6 channel‘s input and output jacks individually to change levels or convert balanced to unbalanced or vice versa. You can use some jacks to split and others to mix at the same time. Reasonably low distortion and noise. My use is to mix both stereo outputs from my preamp down to mono for my sub. No matter which amp (I just bought a second one to play with) I am using, the sub gets a signal without putting a passive mixer on the pre-outs and degrading channel separation. Pretty cool little device and since it says Behringer on the top, cheap and guaranteed for three years.