I’ve wondered about this option in Instrument Settings -> Midi Properties, since I first saw it in Renoise 2.0 b1. Thought I would figure it out but I don’t, and I can’t find any info about it either. So what does the “ext. Midi / LineIn Ret” optiondo?
(By the way, have I dreamt or couldn’t you set a negative MIDI-delay? I recall that I’ve been able to do this in the past but currently I can’t get this to work now in either 1.9.1 or 2.0 (I can only set positive delay). Maybe I’m using the wrong MIDI-drivers or something after my recent OS-reinstallation.)
LineIn Return is in combination with the Line-In device where you can set the “MIDI return”. In this way you can set a close circle and apply a sort of midi delay compensation regarding external devices.