The other possibility, since it happens on low notes, is that the DCO is only capable of changing pitch at the beginning of a cycle. Going back to what Jinsai wrote, 1/.024sec is 41.7 Hz, which IIRC is a low F. If you had a free running DCO that can only change frequency at the start of a cycle (perhaps because it reloads the timer on some kind of interrupt tied to the start of the cycle), and you played a low F and then jumped it to a high note, in the worst case it would take 24 ms to respond to the frequency change. However, it does seem like there would be odd effects with modulation if this were the case. But maybe not. I'll try to rig up a simulation in Csound.Stab Frenzy wrote:The theory that's been suggested by a few people is that the processor sends out the pitch control information after it sends out the envelope information, so the envelope opens and you hear a brief bit of the oscs at the old pitch, before it clunks up to the new pitch.masstronaut wrote:Either way this does not account for 24ms of glitch. So what the heck is going on with that?
I don't think the possibility of a Hammond-like key click should be discounted yet. I just went and played with the A100 for a few minutes, and although the key click has the same probability of occurring on any note, it is far less noticable on high notes. I'm not sure why this is. It could be due to high frequency rolloff occurring inside the Hammond. But it could also be (psychoaccoustic) back masking; the high frequency tone prevents your ear from registering the transient. If that's the case, it would appear to apply to the Evolver too.
EDIT: Just thought of something else concerning that last bit... if it's a Hammond-like key click, it should be noticable when playing a series of low notes. Is that the case? Or is it only noticed when jumping from a low note to a high note? If the latter, that would seem to discount the Hammond key click theory.