Random mod source & vowel filter, weird !

  • Today, I wanted to modulate the vowel filter with the random source. I started from the « init » preset and just added the filter, then the random modulation in the matrix. I must precise that I did that thru the Virus TI vst plugin.

    Soon, I noticed that the modulation was evolving on a longer note ! But the random source is supposed to work like a random « sample & hold » value given on each new note and not changing its value untill the next note. Strange...

    I wanted to understand... And by changing the LFO 3 rate, I was able to be sure that it wasn't the random that was the modulation source but the LFO 3 ! =O

    Then, I changed ONLY the modulation destination from filter bank freq (which in this case was the vowel parameter) into filter 1 cutoff. And suddenly, as didn't touch the source : always 'random' from the beginning, the modulation behaved normally as a random source is suppose to !?(:huh:

    And as soon as I put back the filter bank freq destination, the LFO 3 was in reality modulating the parameter with 'random' remaining display in the matrix. :!:"

    So, I had the idea to add filter 1 cutoff destination in the same matrix slot... The filter cutoff continued to be modulated by the random source and the filter bank freq was modulating by the LFO 3 !! 8| :wacko:


    I really think it's time for a real deep, clean, serious and spectacular update of the Virus TI !! :|


    Did I miss something and all this is quite normal ? Can you make the same test ? Maybe by trying without the vst plugin, those issues don't appear (I didn't try : no time to set all up for working on direct midi) ?


    Thanks for any info or help !

  • I‘d like to verify that but I’m currently rebuilding my studio an the Virus is somewhere in between a big pile of musical instruments...


    GESchwalm maybe you could try to reproduce this behaviour?

    Bass Player and Synthesist.
    Virus TI2 Darkstar | Virus TI2 Desktop | Moog Sub 37 | Blofeld | Machinedrum | Monomachine | Analog Four | Digitone | MPC Live | NI Maschine+
    Mac OS X 10.14.6 (Mojave) | Cubase Pro 11.0 | Ableton Live 9.6 | Logic 10.4 | MainStage 3.4 | NI Komplete Ultimate 13 | RME Fireface UFX+

  • It is a curious situation, but like Oli, my Virus is closeted at the mo' to give my limited work space to my Blofeld for some extended overdub sessions for my current recording project. I am very interested though to see if I get the same results as JoPo has on this as soon as I am able.

    Thank you for the reference, Oli. Very thoughtful! :)

  • Hi JoPo, as it seems that both Oli and GESchwalm are experiencing other...technical difficulties, i'll try and reproduce this (sorry for, uh, invading:)


    Yes i confirm that my virus behaved the same way. It's indeed weird, its essentially LFO 3 somehow controlling the filterbank frequency modulation rate although LFO 3 is not really connected to it. It's not connected to anything actually...


    Please see attached pictures for your reference. All other parameters are set to their default values except from OSC balance which I had it set 100% OSC 1 because I wanted to concentrate on a single OSC.


    I simply cannot explain this. I'm sorry I cant help more but at least you may relax; there is nothing wrong with your unit and you did not miss anything, at least to the best of my knowledge. Maybe try to modulate the vowel with a normal S&H LFO instead of using the modmatrix to get what you are after.


    Very interesting find!


    EDIT: I also replicated the same behavior without the DAW - directly on the synth. Note that the parameter here is named FreqShifter Freq.


    ghost modulation.jpg

  • Thank you Psylence for stepping in! No invasion at all! Looks like a mod matrix source internal mis-assignment by Access? Definitely undocumented in the manuals!

    Maybe try to modulate the vowel with a normal S&H LFO instead of using the modmatrix to get what you are after.

    And also check if any source other than Random is also being pre-empted by LFO 3 for vowel filter modulation?

  • Hi JoPo, as it seems that both Oli and GESchwalm are experiencing other...technical difficulties, i'll try and reproduce this (sorry for, uh, invading:)

    LOL :D


    Thank you for your detailed analysis!

    Bass Player and Synthesist.
    Virus TI2 Darkstar | Virus TI2 Desktop | Moog Sub 37 | Blofeld | Machinedrum | Monomachine | Analog Four | Digitone | MPC Live | NI Maschine+
    Mac OS X 10.14.6 (Mojave) | Cubase Pro 11.0 | Ableton Live 9.6 | Logic 10.4 | MainStage 3.4 | NI Komplete Ultimate 13 | RME Fireface UFX+

  • Just tried this myself. And indeed applying the Random Mod Source to the Filterbank actually applies the LFO 3.

    Bass Player and Synthesist.
    Virus TI2 Darkstar | Virus TI2 Desktop | Moog Sub 37 | Blofeld | Machinedrum | Monomachine | Analog Four | Digitone | MPC Live | NI Maschine+
    Mac OS X 10.14.6 (Mojave) | Cubase Pro 11.0 | Ableton Live 9.6 | Logic 10.4 | MainStage 3.4 | NI Komplete Ultimate 13 | RME Fireface UFX+