Analogue-sequencer

> It also looks like *two* similar messages are intermixed. 
> Like two pots are reporting changes.

That makes it sound much more like a failed 4051.

> If I turn down the 
> step #13 velo pot to value 1, I can clear see that a 
> message with value 9x (ninetysomething) is mixed with the 
> message reporting the 1 value. That other message also 
> seems to have an other step number.

If you go to the controller edit mode, the changing knobs will activate
their step LEDs (cc is auto set active when the value is changed), so
you should be able to see which other one it is.

Cheers,
Colin f