开云体育

More or less.

The MOTU MIDI Express has a few functions as a standalone MIDI distributor (I don't have the PCI card, nor any software, so I only use presets). Usually I use the preset "Live Keyboard", which means that all incoming MIDI data is relayed to all output ports, except the one from which the data is coming.

The test where I got the strange stream was done with the preset "Merge all" - everything that comes into the MOTU is distributed to all outputs, including the one the data was coming from.

My MIDI-Interfaces are plucked into the MOTU just like every other device. I am not aware that the presets in the MOTU do any additional filtering.

I must admit I have not watched for the active sensing signal when the MIDI interfaces were plugged directly into the DX7 - I'll look at that. But in the end result, directly plugging them in was never better than going through the MOTU.

On the PCs is no MIDI routing / filtering. I specifically used a MIDI-wise virgin laptop to ensure that nothing like that was going on. However, and here is again a dark hole in my knowledge, I do not know how the windows drivers actually treat MIDI data. What could well be the case is that the drivers do not see fully valid MIDI (if I'm informed correctly, the early firmware in a DX7 did not send the F7 at the end of a sysex dump. But that is something I just read, not sure.

So, potentially, the drivers look at the data, can't find the sysex end, and then just ignore it? Unfortunately I cannot be sure that I actually get the raw serial data.

I am already thinking about putting an Arduino as raw MIDI-receiver into the mix...