Use the Whirlwind IMCOML IMP Line Level Combiner when you want to create a mono mix from a stereo source but need to keep the original stereo signals isolated. It's great for feeding a DAT player or CD into a mono system or single channel on a board. This unit not only combines two line-level signals into one line level output, it also compensates for the 6dB of gain that occurs when two in-phase signals are combined. A handy ground-lift switch breaks the shield connection between the inputs. Connections are female XLRs in, male XLR out.