The Mackie HM-800 is a rack-mountable, 8-channel headphone amplifier designed to provide versatile headphone amplification for artists, musicians, and engineers monitoring through headphones in live stage applications and home, project, commercial, and mobile-recording studios. It features two stereo main outputs via four 1/4" jacks and sixteen 1/4" TRS stereo headphone outputs—two per channel—fed by a customizable blend of inputs. Two stereo main inputs via four 1/4" jacks can be combined with a per-channel 1/4" stereo aux input. Each channel offers stereo/mono mode switching, input selection, and output level adjustments. 7-segment LED meters display main input and per-channel output levels.