Dsan LSP-3 Laptop Sound Port Multi Input Direct BoxLSP 3 is a passive direct box; you may think of it as an extension cord for your crowded audio mixer. It provides 1 8 and 1 4 stereo TRS jacks to accept headphone level computer or instrument audio with loop out RCA phono; 1 4 TRS mono jacks to accept low level signals from instruments or media players; and an 1 8 stereo plug to capture headphone audio from computers, cell phones or media players. There is volume control, and a selector switch for L,