Simulating analog oscillator drift

#1

To make my poly synth less sterile, I'd like to simulate small oscillator drift, as a value to be added to the note input of my oscillator.
What I need for that (I think) is smoothly interpolated noise within a specified range (f.e. [-0.1, 0.1]), and be able to specify the max speed at which it is allowed to change (to prevent sudden jumps/drops).

Can anybody point me in the right direction on how to go about that?
(Or if you have other suggestions for smooth, limited oscillator drift I'd love to hear that as well ofcourse)

#2

And ofcourse right after I typed it I realized one way to do it.

Get a noise value, multiply it with my bandwidth (0.1 for example), and use a glide object to smooth/interpolate. The only problem is that longer glide time means the final value will be smaller, so it's still not drifting within the entire range...

#3

There is a glide fast object:
drj/math/glide_fast

#4

I think that instead of noise it will be better a slow triangle LFO, because the drift of analog oscillators is not random, it depends mostly on slow changes in temperature. If you want a more unpredictable effect you could modulate the frequency of the LFO with another LFO or with some slew limited noise...

I tried with some VSTs and works nice. I tried with Axoloti and found a problem, I can't attenuate the modulation source enough... with minimun gain I still can hear the oscillator getting out of tune... I didn't experiment much... May be you will find a solution.