The one-in 4-out MIDI thru box from MIDI Solutions sends all messages from the input to all 4 outputs. Active circuitry cleans up any skewing of MIDI data bits occurring at the input, ensuring reliable operation in setups that require daisy-chaining or long cable runs. The MIDI Solutions Quadra Thru is MIDI-powered and requires no batteries or power supply. A MIDI indicator LED lights up when powered, and flashes as MIDI data passes through.. Partial list products that have been reported NOT to provide power to the MIDI Solutions products: Alesis DM10, ControlPad, Micron, Q and QX series keyboards, SamplePad, SR18, Trigger|iO, USB-MIDI Cable, Vortex, Arturia BeatStep, Minibrute SE, Boss FC-50, GT-5, GT-8, GT-10, GT-100, GT-Pro, RC-50, RC-300, Dave Smith Instruments Mono Evolver Keyboard, Mopho x4, Prophet '08, Tempest, Tetra, Edirol UM-1 and UM-2 USB MIDI Interfaces, UA-25, Elektron Machinedrum MK1, Monomachine MK1, Focusrite Saffire, Scarlett, M-Audio Axiom Pro 61, Midisport 1x1, 2x2, 4x4 USB MIDI Interfaces, Oxygen 25, ProKeys Sono 88, Radium, Native Instruments Komplete Audio 6, Maschine MK2, Traktor Audio 10, Studiologic MP-113, MP-117, Numa Nano, Numa Nero, TMK 88, Yamaha 01X, AW2400, EZ-TP, GT1, GT2, i-MX1, KX8, KX61, MOX8, MOXF8, MX49, MX61, NP-30, NP-31, P Series keyboards, PSR275, Tyros5-76, WX7