Very Hacky Workaround to the Multi Channel Midi Note Off Bug

Right...

So I've made a very hacky work around to the very annoying multi channel midi input note off bug. Been bugging me for far too long so I've made a little USB Midi Device which can sort of get round this issue.

It's a USB Midi interface with a single Midi Din input. The USB Midi interface shows up as 16 different Midi ports on the Akai. Each Midi channel received at the Midi Din input is routed to it's own specific port. So Midi channel 3 is sent to USB port 3.. Midi channel 7 is sent to USB port 7, so basically each Midi channel gets it's own port.

By giving each Midi channel their own port, they don't get affected by the note off bug. It's a crude but effective work around if anyone like me REALLY needs to use multi channel Midi input, and can handle putting a few electronic components together in a breadboard. Parts are cheap, and it's Arduino/Teensy based so pretty simple to do.

I'm still hoping for a fix for this soon.... But I couldn't wait, so I needed some sort of solution. I've only just cobbled this together this morning, so it could do with more testing, but it seems to do the job!.

Happy to share what I've done if anyone is interested, but obviously there are risks to plugging homebrew stuff into the USB port on your Akai. Maybe I'll do a video once I've played/tested some more

Pic:

https://ibb.co/VCYp3R7

(McMIB (Multi-Channel Midi Input Bug))

Not quite sure what you're saying....

The note off midi input bug only affects Midi channels on the same port.

E.g

C3 note off on port A, Midi channel 1 can affect C3 on port A, midi channel 2.

C3 note off on port A Midi channel 1 DOES NOT affect C3 on PORT B, midi channel 2

Just confirmed that this works by using my hapax just by using usb and midi in. If I use two channels on two separate tracks on usb, I get the note-off issue. If I use usb for one track and midi for the other, playing the same note on track 2 doesn't send a note-off to track one.

Another really crude way to do this would be to use keyboard ranges and transpose so that you're never sending overlapping notes, but that could be annoying on one end or another.

I have a trip next week where I could use a multi-timbral synth with more than 4 layers and this is perfect. I have a mioXM that I'm going to try to use to this remapping, otherwise I have a couple of devices from tindie I can do this too.

https://www.tindie.com/products/deftaud ... -usb-host/
https://www.tindie.com/products/Robertr ... pico-midi/



I've already been planning to do something similar with the Analog Rytm to map input CC's from one channel to output CCs on different channels.

dstengle wrote:I have a mioXM that I'm going to try to use to this remapping, otherwise I have a couple of devices from tindie I can do this too.

You should be able to do this with the MioXM editing tools. Just route a Midi in Din to multiple USB Host ports, and stick a filter on each host port so it's only allowing one Midi channel through. The tindie boards should do the job too. The initial circuit/code for mine was based on the Teensy 3.2 version of the tindie board.

I was using the CME U6 interface prior to this, as that has routing/filtering software which could do this too, but unfortunately only exposes three USB ports to the MPC which meant I was limited to only three channels.

submo wrote:

dstengle wrote:I have a mioXM that I'm going to try to use to this remapping, otherwise I have a couple of devices from tindie I can do this too.

You should be able to do this with the MioXM editing tools. Just route a Midi in Din to multiple USB Host ports, and stick a filter on each host port so it's only allowing one Midi channel through. The tindie boards should do the job too. The initial circuit/code for mine was based on the Teensy 3.2 version of the tindie board.

I was using the CME U6 interface prior to this, as that has routing/filtering software which could do this, but unfortunately only exposes three USB ports to the MPC which meant I was limited to only three channels.

Filtering is exactly what I ended up doing and it worked just fine. I considered using remapping too but filtering is easier.

I have the 4.1 version of the teensy board from tindie and I used to have it set up to effectively filter by mapping channel to output port of same number in order to keep some older synths isolated from each other.

I have a second copy of that board I haven't built yet, but I got the ethernet for it and I'm planning to try the rtp-midi support on the teensy.

Thanks for pointing this out! This makes the mpc/force infinitely more useful in my setup again. My biggest limitation right now is the limited USB support on the hapax. It's amazing how many ports multi-timbral synths quickly eat up and I haven't even tried MPE yet.

Nice find.
Its amazing workarounds people come up with, so as to coverup the complete ineptitude and incompetence of inmusics developers. It reminds me of retronyms, in fact it could be retronyms.

Nice! I'd give it a try. I've plugged all kinds of weird hacky usb shit into my mpc. It doesn't seem to mind.

The MPC-X (SE) has two input din 5s and four output din 5s, are they affected by the bug?

Neurone wrote:The MPC-X (SE) has two input din 5s and four output din 5s, are they affected by the bug?

All MPC's are affected unfortunately as well as the Force. The problem is with Midi input only I do believe. If you send more than one Midi channel to an input port (USB or DIN) at the same time, note off messages from any Midi channel will affect every other Midi channel on that same port. Even if the Midi channels are not assigned to any tracks on the MPC, they can still affect the Midi channels that are assigned.

It's a pretty big problem if you want to use the Akai's as a multi timbral sound source with external sequencers where you'd need to send multiple midi channels on a single port, or if you want to use multiple controllers at the same time, on different Midi channels connected to the same port. Basically you cannot send more than one Midi channel at a time to a single port without the risk of the Akai corrupting the Midi stream.

Most users probably don't need to do this so are mostly unaffected by this bug. But fundamentally the Akai's should not be doing this, and they're definitely not adhering to the Midi standard here.

There's a pretty lengthy discussion on this here:
viewtopic.php?f=48&t=210361

HTH

submo wrote:

Neurone wrote:The MPC-X (SE) has two input din 5s and four output din 5s, are they affected by the bug?

All MPC's are affected unfortunately as well as the Force. The problem is with Midi input only I do believe. If you send more than one Midi channel to an input port (USB or DIN) at the same time, note off messages from any Midi channel will affect every other Midi channel on that same port. Even if the Midi channels are not assigned to any tracks on the MPC, they can still affect the Midi channels that are assigned.

It's a pretty big problem if you want to use the Akai's as a multi timbral sound source with external sequencers where you'd need to send multiple midi channels on a single port, or if you want to use multiple controllers at the same time, on different Midi channels connected to the same port. Basically you cannot send more than one Midi channel at a time to a single port without the risk of the Akai corrupting the Midi stream.

Most users probably don't need to do this so are mostly unaffected by this bug. But fundamentally the Akai's should not be doing this, and they're definitely not adhering to the Midi standard here.

There's a pretty lengthy discussion on this here:
viewtopic.php?f=48&t=210361

HTH

On my Force I can send multiple tracks to the same port fine. It only when I record multiple tracks on the same port that I run into the issue. Is this the case for anyone else?

B-Wise wrote: On my Force I can send multiple tracks to the same port fine. It only when I record multiple tracks on the same port that I run into the issue. Is this the case for anyone else?

Sending multiple Tracks/Midi channels out to the same Midi OUT port doesn't seem to be affected thankfully (that would be REALLY bad ). It's only when multi channel Midi is received on the input ports that the that issue happens.... For me at least.

Hello

Is there a way to simulate submo's hack using a PC running Midi-OX software between the "multichanel synth source and the MPC" , or using a MidiHUB from Blokas (https://blokas.io/midihub/)

Thank you

Regards

denony wrote:Hello

Is there a way to simulate submo's hack using a PC running Midi-OX software between the "multichanel synth source and the MPC" , or using a MidiHUB from Blokas (https://blokas.io/midihub/)

You can do this with the Blokas Midihub, although you'll be limited to only four MIDI channels (You could push it to five/six channels if you use the hardware MIDI DIN ports on the MPC as well). Here's a file for the Midihub Editor:

https://drive.google.com/file/d/1Zh7BRU ... p=drivesdk

Plug the Midihub into the MPC via USB... Use MIDI input A (DIN) for your MIDI source....
MIDI Channel 1 will go to the first USB port
MIDI Channel 2 will go to the second USB port
MIDI Channel 3 will go to the third USB port
MIDI Channel 4 will go to the fourth USB port

All channels will be remapped to Channel 1, on their respective USB port, and any realtime messages like clock, play, etc will go to the first USB port only.

HTH

submo wrote:You can do this with the Blokas Midihub, although you'll be limited to only four MIDI channels (You could push it to five/six channels if you use the hardware MIDI DIN ports on the MPC as well). Here's a file for the Midihub Editor:

https://drive.google.com/file/d/1Zh7BRU ... p=drivesdk

Plug the Midihub into the MPC via USB... Use MIDI input A (DIN) for your MIDI source....
MIDI Channel 1 will go to the first USB port
MIDI Channel 2 will go to the second USB port
MIDI Channel 3 will go to the third USB port
MIDI Channel 4 will go to the fourth USB port

All channels will be remapped to Channel 1, on their respective USB port, and any realtime messages like clock, play, etc will go to the first USB port only.

Thank you very much for your response. I really like it.

I downloaded your file from Googledrive and stored it in my Blokas Minihub , but I can't get it to work: the MPC does not receive any MIDI events.

I configured my MidiCake ARP (I know you know it) so that Arpeggiator 1 goes to its MIDI OUT DIN channel 1, apergator 2 goes to its MIDI OUT DIN channel 2, etc.

I connected the MIDI DIN OUT of the Midicake ARP to the MIDI DIN IN A of the minihub and the USB port of the minihub to the USB port (type A) of the MPC.

[ARP] DIN OUT ----> DIN A IN [Minihub] USB ---> USB [MPC]

In the MPC preferences/MIDI, It displays:

Minihub MH-1RAJT6P A
Minihub MH-1RAJT6P B
Minihub MH-1RAJT6P C
Minihub MH-1RAJT6P D

Then, I configured :

on Track 01, Input Minihub MH-1RAJT6P A port 1
on Track 02, Input Minihub MH-1RAJT6P B port 1
on Track 03, Input Minihub MH-1RAJT6P C port 1
on Track 04, Input Minihub MH-1RAJT6P D port 1

I started playback on the Midicake ARP, the Input A LED on the minihub blinks (but the other LEDs remain off, apart from the one on which your preset is loaded) and the MPC indicates that it is not receiving MIDI events.


Click here for Image 1

Click here for Image 2

I do not know what it is not working.

Update : If I replace the MPC by my computer and launch Blokas Minihub software, then the MIDI monitor windows does not show MIDI activity (while Midicake is playing)


Click here for Image 3

But the link between Midicake ARP, minihub and my computer is working because if a create a [MIDI IN A] --> [USB A] link, ARP notes are displayed in the midi monitor window


Click here for Image 4


Thank you