Hello there,
Something on my Moog Sub 37 has grabbed my attention lately. When I go into the square and pulse wave range of any of the 2 oscillators and the feedback knob is turned completely up, the tone begins to change octaves randomly. My question is, if that is a normal behavior.
Thanks in advance.
I do think so. I don’t have my unit at my side but hopefully I am able to do the same test tomorrow morning and confirm
Thank you!
Indeed, when you get to the square and pulse the feedback goes nuts.
I couldn’t tell if its the pitch that is jumping but the sound does go wild. The same behavior to a lesser extent is shown on the sawtooth and triangle. I found that if you turn the Sub 1 osc up it goes away, almost completely
Yeah, mine does it, too, and I LOVE it! I get some great effects by setting the feedback control just slightly before the wildness starts and then modulating the wave shape with an lfo, velocity, or pressure.
I definitely see it as a feature, not a defect.
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Moose
Ok, thank you all! This community is awesome!
Hi DStocker,
I think one way of looking at it is that the very point of feeding the output of a system back into itself is precisely to create these types of instability. And that the exact nature of these instabilities can vary per unit.
Why? Because the nature of system feedback strongly accentuates any aspects that have even the slightest amount of gain above unity. As the feedback amount increases, these qualities overpower other sonic aspects that have a gain that’s less than unity.
So each unit, while being very similar to other units, may exhibit different feedback behaviors based on slight differences in their component values, as well as their trimpot settings.
Embrace the chaos!
Yes it is normal behaviour, and even desirable to some (including me).
Feedback by its very nature is inherently unstable and unpredictable and that’s what makes it a fun and creative opportunity.
Check out Robert Fripp and Brian Eno’s collaborations.
Thanks again for your responses and explanations!