Aalto behavior in MPE mode

I’m working on MPE support for an iOS MIDI controller (another topic about that coming soon :slight_smile:), and have a couple of questions about how Aalto handles things. I suspect these will mostly be for @randy?

In the most recent revision of the specification, I would expect to do something like sending Z axis data as either Channel Pressure, or as a CC 70/102 combo for 14-bit resolution. Does Aalto support the 14 bit mode? And is it safe to assume that the after outlet will output that data in either case?

The pitchbend axis seems pretty straight forward, since that behaves normally, but on a per-note-channel basis.

In the specification, the third axis, timbre, should be sent as a CC 74/106 combo, and I’ve found this post on the old forums that indicates cc 74 will come out of the y outlet in Aalto – Will this one also handle the 14-bit combo message?

And how does Aalto handle zones? Do I need to send it any data to use in a “single zone” configuration?

I still have a fair bit of coding to do before testing this out, but will probably get to it in the next few days, and want to make sure I know what to expect when diving in.


That’s great you’re working on MPE support. Please keep me posted. MPE is just gathering steam so if something does not work or seem to behave right, let me know.

Aalto doesn’t currently use the high res data for any controllers.

Channel pressure in MPE mode works as it should in the spec, as far as I can tell. The after outlet for voice n = Main channel pressure + voice n channel pressure.

In Aalto’s MPE mode the three rightmost outlets of the KEY module send the mod, x and y signals. x and y are always channels 73 and 74. The mod signal sends whichever channel number is selected using the mod dial.

Aalto defaults to the “single zone” configuration and doesn’t yet handle splits.

Aalto KEY module outputs by protocol

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Thanks a bunch for the info!

I haven’t yet tested Aalto with the modulation or x y. Should have some tests done by the end of the week. Per-note pitch bend sure is fun though :slight_smile:


Great. I love when I can hear that there are fingers behind the notes, if you know what I mean.