Repro 1: clock rate vs LFO speed

[ghostwhistler]

I want to assign the Mod Wheel to the CLock rate to modulate the speed during a sequence (played in the vst's own sequencer).
I cannot do this.
But I can assign the MW to the LFO.
So, is there a formula I can use to calculate the required LFO speed to match the clock speed, for example 1/8 triplets.
Unless I can match the speeds exactly the sequence will play out of time and thus suck.
I do not want to suck.
Thanks

[Urs]

We do not encourage modulating clock rate, because drift and thus running out of sync would be inevitable. You can try this for yourself by MIDI Learning the Clock parameter, play a sequence and switch tempo. After very short time, the notes will be out of sync.

The same will happen when using the LFO. Unfortunately I'm on vacation and thus can't verify any formula to match LFO speed to clock rates, but I'm afraid I doubt that a 128-step MIDI controller will hit the exact values needed.

To be fair, there are ways around this, but they require a different paradigm and feature set than what the reference hardware was about. We have tried to solve this in Hive, but even then modulating sequencer clock rate often leads to unexpected results.

[ghostwhistler]

We do not encourage modulating clock rate, because drift and thus running out of sync would be inevitable. You can try this for yourself by MIDI Learning the Clock parameter, play a sequence and switch tempo. After very short time, the notes will be out of sync.

The same will happen when using the LFO. Unfortunately I'm on vacation and thus can't verify any formula to match LFO speed to clock rates, but I'm afraid I doubt that a 128-step MIDI controller will hit the exact values needed.

To be fair, there are ways around this, but they require a different paradigm and feature set than what the reference hardware was about. We have tried to solve this in Hive, but even then modulating sequencer clock rate often leads to unexpected results.

Thanks. So you are saying that the very fact of modulating the clock rate means that it will stop playing in time even when there is no modulation actually happening?

[Urs]

The problem is only when you change modulation while playing a sequence. If you play a sequence at constant tempo, no drift occurs.

However, MIDI CCs do not necessarily have the right resolution to hit perfectly synched values.

If you need this live, sounds like an opportunity for a host developer. If you need this within production, I'd still recommend programming the sequence in the host and copy/paste/stretch it accordingly for best results.

(I'll keep thinking about this though, maybe there's a mathematically correct way of solving the issue *including* staying in sync)

[EvilDragon]

The answer is quantizing modulation changes to a certain division of the grid (say, quarter notes), along with limiting the values you want to modulate between (you don't necessarily want/need the in-between dotted and triplet values between 1/4 and 1/16 in a lot of cases, you want a straight jump) - having less values to switch between will allow even 7-bit CCs to switch between just the values you want. Massive X did this commendably, where for tempo syncable parameters you get a slider that switches between 5 values, and you can set exactly what those 5 values are.

But yeah, this is quite rare.