Pad perform custom note map randomly changes other pads

So, I acquired a TR-8 - yes, I know, but it is supreme for grooving (I love standing in front of my setup and moving dancishly as I noodle) and the one-knob-per-function UI is easier and more fun to explain to the kids than diving into piles of screens. Anyway, in spite of my full awareness of how limited the TR-8 is compared to the MPC, I nevertheless inevitably desired to record its MIDI output on the MPC and also sequence it from the MPC. So here goes MIDI mapping, using Pad perform's custom setting.

Cutting to the chase: I'm losing my mind. Changing one custom note map randomly changes others. I manage to enter a few and next one I enter changes one of those I already entered.

And to add insult to injury, undo generates yet another random mapping variant.

I suppose that custom notes mapping obeys secret rules... Anyone aware of them ? I had posited that maybe only chromatically ordered mappings are allowed - but experience proved this hypothesis invalid.

Here is a video demo of the infuriating behaviour....

Don't use the data wheel, instead use the double tap drop down option.

In your example, pad A10 is Bb2, but when you turn the data wheel, it briefly becomes A2, so the MPC tries to juggle around the notes to accomodate this ( i.e. it looks at where the existing A2 is assigned and now has to put another note there). You continue to turn, so next Ab2 is briefly selected, so the MPC looks at where the existing Ab2 is and has to assign a different note there. You might eventually 'stop' at B1, but throughout that journey you actually selected every single note from Bb2 to B1 (albeit briefly each time). This is what causes the seemingly random note re-assignments.

Using the drop down option avoid this as you go directly to B1.

Wooohooo - it worked... Thank you MPC Tutor for this instantaneous unblocking and explanation of a behaviour which, I suppose, made sense to someone at Akai.

Damn, what a booby trap.

Now, before I go to bed, I'll allow myself some grumbling about "Pad color not available for MIDI program": grmbl.

Thanks again !

Jean-Marc Liotier wrote:[..] Now, before I go to bed, I'll allow myself some grumbling about "Pad color not available for MIDI program": grmbl

I found a solution: "color the pads in a midi program by directly editing the program file with a text editor. The pad colors are represented by a series of numbers ie 9780543,. You can create a drum program and color the pads to find out which numbers represent which" - nice to know, but I'm not that eager to color my MIDI program's pads... But why, Akai - why ?