Problem with addictive Drums and a simple expression map

I have created a simple expression map that switches channels for different drum sets which I have loaded in VEPro. I have there three Addictive Drums patches: sticks (ch1), brushes (ch2) and mallets (ch3) . The problem is that this expression map works only some of the time - when I enter a playing technique to the score it works as expected but then later on it might randomly stop working (although nothing has changed in the drum part). Re-entering the playing technique fixes the problem usually.

Here is just a screenshot of the expression map, it is very simple:

The playing techniques are set up like this:

If there is a better way to do this (change between sticks, mallets and brushes) I would be curious to know. I’m trying to avoid having three drum sets for one player, that is the reason I decided to instead use channel switches. Addictive drums 2 has the same mapping for every set, which allows this.

The use of expression maps in conjunction with percussion maps is not fully supported at the present time, and you may well run into these kinds of issues when trying to use them together.

Thank you, Daniel. It is very helpful to know this.

**Leigh

For anyone wondering, I seem to have found a solution to this problem: I had to add relative channel switches of 0 to both “init” and “natural” entries in my simple channel switching expression map:

This seems to prevent dorico from switching to channel 1 when it is not supposed to. I think it might be related to the problem, that dorico sends midi CC and other controller data when notes are selected, even when this setting is unticked:

Screenshot 2022-06-09 at 16.15.46

I’m suspecting that it was these messages that forced my expression map to switch to channel 1 when editing the drum staff.

Anyway, with this modification this seems to be a good way to have only one drum set in dorico, but multiple playback possibilities for it (sticks, mallets, brushes, hands etc.)

EDIT: well, it still changes sometimes to channel 1 even with this, but at least not as often as before it seems.