Check the listing for details. Keith McMillen Instruments KMix Audio Interface and Digital Mixer 1978813225 OB. Condition: Used. Listed at 402.38 USD. K-Mix is an all-in-one audio interface, control surface and programmable mixer that is a great space and time saver in either live or studio environments. On the input side, it features two low-noise preamps accessible through a pair of XLR/TRS combo jacks that supply 48V phantom power if needed. It additionally features six TRS line inputs for a total of eight balanced inputs. Audio and MIDI in and out can be managed via mini and micro USB. Outputs include stereo headphone output along with eight balanced ¼ in. TRS jacks (outputs 1 and 2 function in default as master stereo output left and right).One aspect that really sets the K-Mix apart are its multi-function, touch-sensitive strip faders and rotary controllers.