Anyone using iVCS3 as an AU in AUM?

Hi there,
after hanging around here for a while, the time has come for my first question:

is anyone using iVCS3 as an AU in AUM? I’m having difficulties getting (midi-) remote to work.
It works totally ok in the standalone version (even with 14bit midi), but the AU seems sort of messed up…
Example: I assign any midi-CC to VCO1 frequency. When I move my controller from val 0 to val 1 the frequency jumps to approx. 50%. I move my control a little further (val 10) and the frequency moves in large steps up to 75%. The remaining 117 steps of my controller move the frequency up to 100%.
Strange, isn’t it? Only those parameters whose range is 0-1 behave as expected.
Am I missing something here?

btw: It’s not only with midi, when you make that one parameter accessible in the main AUM screen, you get the same result when using only the 'touch-control'

Comments

  • Could it be a controller issue? RELATIVE or ABSOLUTE operation modes? What type of controller? Just a thought.

  • I don't have iVCS3 installed to verify this, but it sounds like it's not using the correct kAudioUnitParameterFlag_DisplayLogarithmic AUParameter flag for frequency and such parameters.

  • Howdy,
    thanks for your answers.
    @jj_liljedahl: sounds like it’s beyond my control, think I’ll drop them a support mail.
    Just for further clarification, here’s a screenshot of iVCS3’s parameter list:

    @Morgman73 : its totally controller independent. My controller is a homegrown device, but its the same with an Akai Lpd8. Since I like it so much, I’d like to share a picture:

    Have a nice sunday.

  • wow, I like that controller! is that your own design?

  • @palm said:
    wow, I like that controller! is that your own design?

    Yep, completely homegrown. Well, the layout is obviously given by the VCS3...
    No need to mention how much I like the iVCS3, don‘t I?

  • wow, very nice!
    how is it sending midi? does it use an arduino or something? I would love to build a controller of this sort, but I'm very new to diy electronics.

  • @palm said:
    wow, very nice!
    how is it sending midi? does it use an arduino or something?

    It‘s a Teensy 3.2. No rocket science involved since it has tons of analog inputs and -most important- comes with USB-midi out of the box. Works flawless with any OS.

  • Highly recommend the following two books for anybody wanting to tinker with Arduino/Teensy:

    Arduino for Musicians - http://global.oup.com/us/companion.websites/9780199309320/book/

    And

    https://thonk.co.uk/documents/Books/MAS_sampler.pdf

    You need to have basic electronics skills but it's nothing to be scared of and there's another Make book which will guide you through those basic skills.

    https://makezine.com/wp-content/uploads/2014/01/make-electronics-excerpt.pdf

    Both of the Make pdf samples are generous with 40+ pages each, so they should provide enough information to help you decide whether brushing up rusty soldering skills will be a worthwhile journey.

  • @j_liljedahl said:
    I don't have iVCS3 installed to verify this, but it sounds like it's not using the correct kAudioUnitParameterFlag_DisplayLogarithmic AUParameter flag for frequency and such parameters.

    Hi Jonatan, the iVCS3 knobs goes from 0 to 10 and the value are used as index to interpolate a table contains the real VCS3 values.

    I've encountered some problems with AUM using the kAudioUnitParameterFlag_DisplayLogarithmic since (as know) the minimum value must be > 0 (e.g. 0.00001) for this reason I've decided to skip all of these knobs with the minimum value is zero although they are exponentials. Maybe you could clamp in AUM the value to the next minimum value grater than zero?
    Cheers

  • @scarbo said:

    @j_liljedahl said:
    I don't have iVCS3 installed to verify this, but it sounds like it's not using the correct kAudioUnitParameterFlag_DisplayLogarithmic AUParameter flag for frequency and such parameters.

    Hi Jonatan, the iVCS3 knobs goes from 0 to 10 and the value are used as index to interpolate a table contains the real VCS3 values.

    I've encountered some problems with AUM using the kAudioUnitParameterFlag_DisplayLogarithmic since (as know) the minimum value must be > 0 (e.g. 0.00001) for this reason I've decided to skip all of these knobs with the minimum value is zero although they are exponentials. Maybe you could clamp in AUM the value to the next minimum value grater than zero?

    Logarithmic params can't be 0, that's just how it works mathematically :) You should either use the real min/max values for the parameter, or if you want a linear scale like 0 to 10 you also need to convert it to the correct curve:

    freq = pow(maxValue/minValue, value/10.0) * minValue; // for 0 to 10
    

    As it is now it's half of two worlds, leading to trouble.

    Cheers

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