How do you make the Klaus Schulze "Space Flitter" sound?

[MFOSser]

I have experimented with my modest modular but have not come up with the exact sound of Schulze's "space flitter". By which I mean this sound in Timewind (1975)...

https://youtu.be/qBn0Jnf7_3M?t=39

a sort of oscillating whistling sound that has both a noise and tone sound combined and oscillated by LFO. Froese used it too in his Aqua (1974) album

I was wondering if Klaus used a "Krautrock Phaser" for this or can it be replicated using VCO, noise and a few LFOs and VCAs.

A simple approach without need of a "Krautrock Phaser" would be great.

Thank you for any input.

[goedikey]

There are at least 3 sounds on the begininng of track ; a string machine pad, some windy sounds (filtered noise) and finally the whistling sound.

Whistling sound is also filtered noise but using an LFO (many cycles per second) to modulate cutoff. There is another slower LFO modulating the cutoff much slower to give it the up and down feel. You need to right type of filter and to set the resonance level high enough. There is also a stereo effect on top of it.

Then there is the sequenced droning portion that comes into play.

[goedikey]

There are at least 3 sounds on the begininng of track ; a string machine pad, some windy sounds (filtered noise) and finally the whistling sound.

Whistling sound is also filtered noise but using an LFO (many cycles per second) to modulate cutoff. There is another slower LFO modulating the cutoff much slower to give it the up and down feel. You need to right type of filter and to set the resonance level high enough. There is also a stereo effect on top of it.

Then there is the sequenced droning portion that comes into play.

[MFOSser]

Thanks for that. Looks like I need more LFOs. I guess you can never have enough of them.

[goedikey]

You'll need 2 Lfos.. the trick then is to keep your filter just above 3/4 open (in the higher pitch ranges) and modulate ever slightly to get a nice sound. If you modulate too much it will be a different sound. Let you ears decide.