Shaper clicks and self-oscillates when modulated
Start with an empty track.
Add an LFO, then a Shaper, both with default settings. Attach the LFO to the Shaper's Amount, and turn it up to 100% modulation. Make sure there is nothing connected to the Shaper's audio input!
Set the Shaper Amount to about 75% and Bias to about 25%.
Turn up the volume a bit, and you should be able to hear a ticking/clicking sound above about 1.5Hz LFO rate. As you turn the freq up more, it becomes a buzz.
Is this intentional? If so, is there any way around it?
It's quite a cool effect if that's what you're after, but I noticed it the other day while trying to just modulate some saturation on an input signal, which was kind of annoying.
Also, if it is intentional, just for my curiosity -- what's the physics/maths behind why this would happen?
Thanks!
Comments
I can't reproduce what you describe.
Are you sure the buzzy sound doesn't come from your amp, speaker(s), headphones?
By the way, the input of your shaper seems to be disconnected.
you are modulating level at relative low frequencies (bias is hipass filter)
20 hz?
what you are hearing is artifacts because your listening equipment can't reproduce that
its at the lowest end of what your senses and equipment are able to get
(u r supposed to hear click click click if u make it faster it becomes a steady tone)
nothing unexpected happening here
(if u have bias at zero position its doesn't make a sound when modulated)
Yeah, I know there's no input, that was my point :-)
The LFO modulating Amount causes the Shaper to make an audible tone even when there's no input signal, and I wondered why. It's not coming from my equipment, you can see it on the oscilloscope in the screenshot. (Maybe it's not obvious from the colours, but that's connected to the output of the Shaper.)
Right, I get that it's just a very low tone, that's what I meant by "As you turn the freq up more, it becomes a buzz". You can actually get some pretty nice harmonics out of it when it's in the audible range.
I'm just curious to get my head around why it happens. In my dumb worldview a processing module with silence in would give you silence out, but I don't know a lot about the mechanics of signal processing.
Oh wait, I guess the bias itself is just another ‘input’ into the shaper function. You just can’t usually hear it because it’s a constant value... but if you start modulating the shaper amount, that constant becomes a cyclic waveform.
something like that??