Hi Y'all, I'm currently enjoying working my way through the Kaivo PDF Manual (which is awesome BTW) and exploring this brilliant synths inner workings and sound palette which is delicious! Really mind bending sounds and architecture, just so much fun to explore! Anyway, through this process I came across a strange phenomenon that I can't explain but its possible its just a MIDI Protocol thing to do with the way that the Pitch Bend CC is handled, so I thought I'd mention it to try and determine if its a bug or a feature!
Basically, there's this amazing Default patch (Kaivo Percussion --> Slap Tube) that sounds (to me) like Indian Percussion such as a Tabla or Dholak and I thought it would be awesome to be able to subtly (or non-subtly) bend it as a drum I used to own had tuning blocks on the side and you could twist them or pull them to create a pitch modulation (its also possible there's a playing style that creates this phenomenon too); but its an awesome sound regardless and really characteristic of the unique Indian percussion sound!
I'm not using an MPE controller, but a cute little Novation Launch-Key-25 Mk3 instead (which is incredible BTW) and it has Polyphonic After Touch on its drum pad section (fortunately for moi)! This is also perfect for what I wanted to achieve and sounds incredible (e.g. simply route After --> Linear Pitch) on the Resonator for instant sonic gratification! I'm so glad After Touch is a feature as it can add an incredible dimension to sounds, and its a somewhat ideal usage scenario in this particular case!
What this made me wonder is if the Pitch Modulation Wheel thingy could be used as well so you could switch between subtler pitch bends (e.g. a semitone) with After Touch, and perform more adventurous pitch deviations (e.g. Whole Tones++) using the Pitch Wheel! Unfortunately when I tried this, it seemingly creates a strange 'stair stepping' like sound (which traditional MIDI's limited CC resolution of 128 steps is known for, but usually with filter sweeps etc)!
Except, its a little more complicated than that as it sounds like the equivalent of tapping a drum membrane gently with your fingernails in a percussive motion, so its appears perceptually more like adjustments with the Pitch Wheel are somehow creating transient spikes/fluctuations, or somehow forcing the Resonator Module to reinitialize its simulation for each pitch deviation?
Fortunately this Patch makes this really easy to hear as the Modulation Wheel is already setup to control the decay, so merely winding it up to maximum allows you to clearly hear the transient stepping as with a lower register (C0 or C1) you literally get seconds to hear its deliciously lush, growling, resonating decay! What I thought was weird is that 'After' doesn't produce the same artifacts even if you crank its range up high but surely that's still limited to only 128 steps of resolution?
Upon further investigation I established that you can create these artifacts with the After Touch drum pad method too, but only if you alter the value of the Resonators Linear Input Dial whilst you are still modulating it (and its still decaying). Further, if you apply a relatively small pitch deviation with the Pitch Wheel, played on a low register (e.g. C1) it doesn't do it, but the higher the pitch the artifacts begin to appear in case that helps investigate or recreate the issue (or understand its cause/effect etc)!?
As such, I'm just wondering... Is there a way that the 'Pitch Wheel' functions over MIDI that is causing these artifacts, or is it actually a form of software bug in Kaivo? I'm just curious either way as naturally I love this synth (smitten in fact) and want to understand its weirding ways as much as possible! Regardless, its an incredible synth Randy - many thanks! :)
I haven't had a chance to dig into this, and I want to double-check before saying anything for certain. But what I think is happening is that the model itself in some modes has a discontinuity that makes a small click at certain pitch transitions. You could probably verify this by connecting the LFO via the patcher in place of the modulation sources you are wondering about. This will rule out MIDI things and provide a smooth source of modulation. So if you're still hearing clicks it's definitely in the model.
Hey Randy, thanks for the advice. I tried what you said with the 2D LFO in place of After Touch (on the Linear Resonator input) and it indeed produces smooth results. However, if you plug the 2D LFO into the Logarithmic Resonator input it always produces the ‘click’ artefacts. I also noticed that if you plug After Touch into the Logarithmic Resonator input, After Touch will also produce those weird ‘click’ artefacts too, so it appears like it’s the ‘Logarithmic ’ input! Then it dawned on me to feed the Key Pitch directly into the Linear Resonator input too, and sure enough it can indeed create smooth transitions using the Pitch Wheel (albeit with eccentricities) lol!
For experimentation purposes, I connected the 2D LFO to the Resonators Logarithmic Input using a tiny output ‘Level’ (0.020) and tried it with a variety of rates including fast (3.0), medium (1.0) and slow (0.5). However, regardless how subtle the ‘Pitch’ changes are, (and whether fast or slow) they always result in the phenomenon (rhythmic clicks which then become controllable by the rate setting) which is actually really interesting in itself as you can use it to generate some weird granular sounds (without using the Granulator)! So it definitely seems likely that the ‘Logarithmic’ input of the Resonator is the driving force behind it (but it can be circumvented)!
So the Pitch Bend Wheel can be set up for extreme Pitch warping like I originally wondered (e.g. +/- 24 semitones), but only if its connected to the Linear and not the Logarithmic Input of the Resonator, which does create some weirdness with bend range according to the note frequency and you have to drive the root note frequency using some other means (such as the sequencer) but I’ve certainly learned lots about Kaivo through this enquiry as inadvertently I explored the 2D LFO which is insanely creative/dynamic!
It’s all good anyway, as I’m able to perfectly reproduce realistic physical drum pitch bends using the ‘After Touch’ feature alone, (I was just curious where mystical rhythmic clicks were coming from)! Also coincidently ‘After Touch’ is ideal really as it’s also unipolar (positive polarity) which perfectly simulates pulling the side drum tuning pegs that can only increase the pitch and return it to its starting point, so it responds the same too!
I just wanted to say a huge thanks for your insight/advice which helped a lot and I’m excited about creating some intriguing physical modelled sounds as a creative exercise (e.g. Tibetan singing bowls, Aeolian harps and importantly some new unimagined ones) …thanks Randy anyway! :)