MIDI learn and erratically move from knob

[bongobong]

I have a trouble here. I try use my MIDI controller (Behringer UMX250) with Ardour and Charlatan (synth). All works very well except the filter cutoff knob. The UI has a frequency curve different from the generic cutoff control. I can link the “Frequency” knob with my midi controller, but when I touch the hardware Charlatan moves erratically. No 0 to 100, or something that, maybe the knob is logarithmic, I don’t know but that seems to be not supported by Charlatan synth internal UI and that is the reason that not possible mapping the values to a 0.0 - 1.0 range.

Is a plugin error? or maybe Can I add something between my MIDI controller and the synth for move constantly?

Peace.

OS: Debian 13
Ardour: 9.2.3
Charlatan: 3.3.2

[bongobong]

Here with new information. All works fine in Carla (standalone) y Qtractor. I reported in Mantis: 0010298: MIDI learn with Charlatan virtual synth has erratic behaviour - MantisBT

[Roger.Wilco]

@bongobong

but when I touch the hardware Charlatan moves erratically

Could be a long shot…
Have you tried flipping whatever you have configured for “Motorised” and test different “Smoothing” values for your UMX250?

Edit->Preferences->Control Surfaces->Generic MIDI->Show Protocol Settings

[x42 (Robin Gareus)]

Could this be caused by moving the knob too fast? or not moving the know to the current value first?

see also:

Feature: Lazy sliders

This is exactly what Ardour does, if you disable “motorized” in Generic MIDI Settings. You can also set the max allowed difference between the values (“smoothing”). Keep in mind that setting it too low may cause issues if you move the slider too fast.

Encoder initial value when a session is loaded

enable-feedback A message is sent to the device when a mapped value changes motorized A physical knob’s position is assumed to always matche the control value If motorized is disabled, Ardour ignores all control events from the hardware until the knob’s position is close to the internal control-value. The “smoothing” control allows to configure this. e.g. If a Fader in Ardour is at -inf dB but your physical knob is all the way up, moving the knob will do nothing at first. There will not…

[bongobong]

Well the documentation bring by @x42 is the correct. I have best results with Motorised but the synth has discontinuous jumps… awful. In the Generic View the information is the same that hardware but the synth has a different value. Is possible create a custom MIDI map and fix this behavior?

[delt (Ardour)]

EDIT: solved. I forgot to enable the “generic midi” control surface. Working as expected now.

Was just going to create a “how do i…” question for mapping MIDI CC’s to change effect/track paramters… perplexity (and online manual) says ctrl+middle click on a widget for “midi learn” but that doesn’t do anything. (ardour 9.2, linux, self-built) Doesn’t look like xfce4’s window manager is intercepting it, since other clients receive it fine.