Filter Cutoff MIDI 0-127 control limitation?

In the Analog Filter module (potentially other filter modules as well, admittedly haven't tested), if you turn Cutoff all the way down, use the arrow next to Cutoff to assign modulator, and assign external CC control, a 0-127 range does not sweep the entire filter. However, if you assign that same CC via-a Morph module, 0-127 controls the full Cutoff range.

Is this the only control known to have this functionality difference? From what I can tell, other parameters with the arrow icon for modulation seem to respond fully to 0-127 CC range without the Morph module.

Any info/help appreciated, thanks!


  • edited June 17

    You would rather map the CC to the cutoff knob directly.

    If you really want to control the modulation depth instead, make sure your modulation source delivers a high enough value to be effective in modulation. It can be scaled and shifted using the Scale+Offset module.

  • To the first part, I use a Morph module and that works (and doesn't get tied to just one project) for my needs.

    I'm talking about the behavior of the Cutoff parameter specific to (at least) the Analog Filter module does not respond to a full 0-127 MIDI CC range (I have tested this several times, and am most definitely sending a full 0-127 range) if you use the triangle icon and assign to the "MIDI CC Controller" module (set to any CC, go for 74 as for General MIDI standards for instance).

    The Scale+Offset module would probably be successful for this purpose, but my point is that it shouldn't be necessary in the scenario I've described. I haven't seen another parameter in Drambo with the triangle icon for modulation control where the entire parameter wasn't controllable from a 0-127 CC range.

  • Drambo inputs go from -1.0 to +1.0 (or 0..1 if unipolar)

    are you sure you’re scaling your input to that range? It does it automatically if you assign directly like @rs2000 said, but maybe you should check if nothing in between is happening. Use the floating scope to be sure

  • As far as "assign directly", I am doing that, via-the Morph module. That actually works better than using the Learn icon at the top because with the Morph module, I can tie that to a Rack instrument I've created and use in any project. I'd just prefer to not have to add one extra module to the Rack instruments I make (and curious if anyone knows of other parameters that also behave this way).

    I am 100% positive I am using a full scaled 0-127 range (as mentioned in previous post). I have used both an MPC1000 and Faderfox EC4, which give visual feedback to confirm a full 0-127 range of the CC being sent to Drambo. Also confiming by long-pressing the MIDI icon on the input of the Rack to doubly-confirm that the full 0-127 range is being received in Drambo.

  • @TimbreChopper

    I've just tested assigning an encoder (LaunchControl XL mk ii) to the cutoff frequency using CC20 with a range of 0-127.

    It maps and behaves as expected.


    When using the Morph module one must remember that you have to set the start point as well as the end point

    so if you just assigned the Morph module to the cutoff filter without setting the lowest freq then the start point

    would be at 130Hz with an end point of 19kHz which could explain why youre having issues.

    In the next screenshot I've assigned the Morph module to the cutoff knob with the lowest and highest points set.

    The Knob from the knob module is set with a minimum of 0 and a maximum of 1.

    One can modulate and or map all the three points.

    Knob on the Knob module, Amount on the Morph module and the cutoff knob on the Analog filter module.

  • @gravitas I'm sorry if my explanations have been unclear but that is not what I've described at all.

    1. The Morph module is working for me, as I mentioned/implied in every post I've made here. As I also mentioned, I use the Morph instead of the MIDI Learn function in your first screenshot because then I can use it in any project.
    2. As also mentioned in my last post, the issue is when assigning the "MIDI CC Controller" module to the Cutoff parameter in the Analog Filter module. Assigning the standard way via-the triangle icon next to Cutoff and then making sure that Cutoff is turned all the way counter-clockwise and the new "MIDI CC Controller" icon that shows up next to Cutoff is set all the way clockwise. This is literally the only parameter I've run into in Drambo that has that triangle icon, but a full 0-127 MIDI CC range will not control its full range. Try replicating this yourself.

    Really I should have posted this in "Feature Requests" because what I'm describing seems like (no offense to anyone) a bug. So apologies for posting in the wrong area.

  • edited June 21

    @TimbreChopper well observed, and there's a good reason for this behaviour to be desirable:

    Cutoff frequency follows the pitch signal precisely, just in case you want to use a filter with high resonance values for generating sound.

    One octave equals adding 0.125 to the pitch signal, and 1/.125 = 8 octaves are not enough to cover the full frequency adjustment range.

    To solve your quest:

    You don't have this "problem" when mapping the CC to the Cutoff knob directly.

  • Thanks, but my desire is specifically for external MIDI control, it's why I'm focusing on the "MIDI CC Controller". I'm not sure why this is the only parameter that would have such scaling issues. As mentioned, every other knob with the modulation icon next to it does not have an issue covering full range within 0-127 MIDI CC control. With the Morph being assigned to Cutoff, and the Morph amount being controlled via-MIDI CC, it is steppy but does hit the full range. (hoping for NRPN support at some point but that's another request/thread)

    One thing I hadn't mention until now, I have also always assigned Key to the same Cutoff parameter and that seems to work as expected. But when either that is not assigned or turned all the way down when assigned, the Cutoff issue I've described in this thread persists.

    It's a small request ultimately because realistically it just removes the need for the Morph module and the MIDI CC Controller module would work on its own (like as far as I can tell, it will with the Resonance and Tone parameters on the same Analog Filter module).

  • @TimbreChopper That's one of the compromises that have to be done to facilitate native control. Honestly, I wouldn't want to give up precise pitch control for full scaleCC control, and you can always scale the value coming from the CC Controller without a problem.

  • @TimbreChopper

    Was this what you meant?

    I scaled up the Midi COntroller ouput signal to 2 and it covers the entire frequency or almost without being super precise.

    I did the same with the Filter module with similar results.

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