Variable volume output between VCF modes
  • Hello everyone

    I’m new to this community and would like to start things of by saying that i really love what Olivier is doing with Mutuble Instruments and all the community in general.
    I’m sorry if it will be a dumb question or if it is an obvious answer but i cant seem to find it in the manual or in this troubleshooting section.
    I’ve already successfully assembled a shruthi and kind of successfully assembled an Anushri without any major problem, but im getting this awkward variable volume output in my anushri between VCF modes. (High-pass filter being much higher in volume than the other two modes)

    Due to my career i travel a lot and since i work in economics and many times am forced to be faaar away from my pretty humble amateur studio, it is not possible, for now, to test if there is something wrong with my anushri.
    So the reason for this long post, since i was only able to enjoy my freshly assembled anushry for one night and left intrigued by that volume question. I’d really love some feedback about if that is normal, if i am just dumb or if it is something wrong with my anushri

    Once again congratulations on what you are achieving with this project

    Thanks in advance

  • This is not a problem, just how a filter works…

    The sound of basic waveforms like square or saw have a spectrum with decreasing energy – they have more way more energy in the lowest harmonics than in the higher ones. So the output of a high pass filter (which removes the lowest harmonics) will have less energy than the output of a low-pass filter (which removes the higher harmonics). The bandpass filter eliminates harmonics outside a small frequency band ; so the higher the cutoff, the lowest the signal energy (as you increase cutoff, you select higher and higher harmonics, which all have a decreasing energy).

  • Thanks for your quick response

    I would think that way but if i decrease the cutoff all the way isnt expectable the same volume on each mode since the filter presumably isnt cuting nothing?

    Once again sorry if this is dumb… Im only trying to understand if that was a normal behavior

    I have learned pretty much around here but by no means want to waste anybody’s time

    Thanks again

  • In high-pass mode, the filter does nothing when cutoff is set to the minimum. In low-pass mode, the filter does nothing when cutoff is set to the maximum. In band-pass mode the filter is always eliminating something, so the output will always have less energy than the input (except if the input has only 1 harmonic, but this won’t happen with a square or triangle signal)

  • It seems that everything is ok then…really love the anushri :)

    Thanks pichenettes for your help…and for your synths!