Multichannel MIDI bug -- any interface with 16+ host ports?

It looks like the MPC multichannel MIDI bug is here to stay -- if we're crossing the threshold from MPC2 to MPC3 with it, I can't imagine it getting fixed any time soon.

steps to reproduce:

set up 2 tracks which produce pitched audio from a keyboard or sequencer MIDI signal

track A: respond only to MIDI channel 1
track B: respond only to MIDI channel 2

1. send a sustained note on to MIDI channel 1 (note on without a note off)
2. send a staccato note (same pitch/note value as sent to channel 1) to MIDI channel 2 (note on with note off)

the note on MIDI channel 1 will be killed by the note off sent to MIDI channel 2

The only practical mitigation I've found (IE. simple, quick and mobile to set up, won't break in performance) is to send more ports worth of the same MIDI information into the MPC to feed to different instruments -- for example the note off values received on MPC A won't kill notes on other channels on MPC B.

I have a 'CME U6MIDI Pro' device that exposes 3 software MIDI ports to the host:


So I can configure this device to duplicate all data going into one MIDI DIN port to all 3 software host ports, giving me 3 MPC instruments that won't kill each other's notes with cross-channel note off communication. Theoretically I can also also patch duplicated streams from 2 of the DIN outputs into MPC DIN A and B and have up to 5 multitimbral instruments coming through a single DIN cable into my £1000+ 'pro audio' device.

Ideally though I'd want 16 host ports so I can connect up to 16 channels through the host port. I wouldn't have thought this is a feature that gets advertised on devices but if anyone has seen a USB MIDI device about that can expose 16 host ports then let me know please.

I did this a while back....
viewtopic.php?f=48&t=217906

You can buy a £20 Teensy board and turn it into a 16 port Midi interface. Add a few components, and bang!

Other possible options would be a MioXM or MioXL if you want 16 ports, but that's a pretty pricey workaround.

submo wrote:I did this a while back....
viewtopic.php?f=48&t=217906

You can buy a £20 Teensy board and turn it into a 16 port Midi interface. Add a few components, and bang!

Other possible options would be a MioXM or MioXL if you want 16 ports.

I have 3 iConnectAudio 4+ devices around from a different era of human development -- same company and probably a lot of the same software/hardware in both boxes. Reckon I'd be able to hack something together with one of those? I did plug it in earlier but I could find a simple way to route data from the DIN in put to the 8 host ports in the 15 mins I spent on it.

submo wrote:I did this a while back....
viewtopic.php?f=48&t=217906

You can buy a £20 Teensy board and turn it into a 16 port Midi interface. Add a few components, and bang!

Other possible options would be a MioXM or MioXL if you want 16 ports, but that's a pretty pricey workaround.

Your DIY solution is exactly what I'm looking for by the way, I will have to read into that a bit more.

Oscar South wrote:Your DIY solution is exactly what I'm looking for by the way, I will have to read into that a bit more.

It's a crude, but kinda elegant fix, and really isn't to hard to get set up.

You can use other commercial Midi Interfaces as long as they support routing/filtering of Midi data. I was using the U6pro prior to this, but I needed more ports/channels (three channels wasn't enough).

If the bug can be fixed by adding an extra layer, making each MIDI channel a separate MIDI interface, then why don't Akai do the same internally. And then add another layer to make the MIDI interface bundle look like channels inside a MIDI interface... and then the bug would be fixed.

HouseWithoutMouse wrote:If the bug can be fixed by adding an extra layer, making each MIDI channel a separate MIDI interface, then why don't Akai do the same internally. And then add another layer to make the MIDI interface bundle look like channels inside a MIDI interface... and then the bug would be fixed.

All I have is questions about why this isn't fixed by now. I've thought about this a tonne as to why this hasn't been fixed. Have they lost access to their MIDI input code? Is this buried in some proprietary driver they cannot alter?... Or just a bandage for some other more serious issues?.... Or maybe they just can't be bothered to fix it? Blatantly, if it could be fixed, I think it would of happened by now. It's not fixed for MPC3 beta which kinda says a lot to me. Shame!

I read somewhere on this forum, speculation has it that the bug was introduced to fix a hanging notes issue. Their "what note-off belongs to what note-on" code was broken and they fixed it by sending every note-off to all channels. ?? What? It's hard to believe this hypothesis because MIDI channels are clearly separated by channel numbers, and every channel has its own universe.