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Weird distortion when modulating Pan(?)

Weird distortion when modulating Pan(?)
« on: March 20, 2017, 03:15:12 AM »
I am experiencing some weird distortion that I am trying to understand the cause of. It occurs on the preset in factory bank 1, program 6, named Wurly Trem ModWheel. The distortion sounds similar to when an audio signal is clipped, but lowering the volume (main, oscillators) does not help.

It is easy to reproduce the noise by playing big chords (both hands, 2-3 octave span) with high velocity. Especially by setting the Mod Wheel above the midpoint and by pressing hard enough to trigger Aftertouch. Both of these modulate the LFO 2 Amount, which controls Pan.

The amount of Pan modulation amplifies the issue, but why? I can't make the distortion disappear without disabling the Pan tremolo effect (LFO 2). I've tried turning on/off modulations and LFOs and have reduced levels but can't isolate the cause. I also tried adding the same LFO 2 modulation of Pan to another patch but can't reproduce the distortion. Why does Pan distort in this preset?

Does anyone else experience this distortion on this preset? I'm running OS 1.4.1 (same issue on 1.4, and probably earlier).

Re: Weird distortion when modulating Pan(?)
« Reply #1 on: June 02, 2018, 10:04:05 PM »
Sorry Mods for reviving an old post, but I am also having the same issue.  I get weird distortion when I try to pan oscillators, when using the pan mod or pan spread mod.  I thought maybe the gain into the filter was distorting so I tried turning down the oscillators, but the weird phasey distortion is still there.  Can anyone help?  Do we have defective Prophet 12's or is it just the way it is?

Re: Weird distortion when modulating Pan(?)
« Reply #2 on: June 02, 2018, 11:03:19 PM »
Hey mate, can you supply a patch, or patch setting so I can try to replicate it please?

As for the original post, I think the amplifier section is simply being overdriven.  I have the same on that patch, but I see the Amp ENV is full, and then you have LFO 4 set (via the mod wheel) to increase it further.

When I reduce this the noise goes away for me.


Re: Weird distortion when modulating Pan(?)
« Reply #3 on: June 03, 2018, 02:38:28 AM »
...
As for the original post, I think the amplifier section is simply being overdriven.  I have the same on that patch, but I see the Amp ENV is full, and then you have LFO 4 set (via the mod wheel) to increase it further.
...

With these procedure is it possible to speed up even more a LFO frequency?

Re: Weird distortion when modulating Pan(?)
« Reply #4 on: June 03, 2018, 03:56:58 AM »
***edit, I’ll leave my original reply below, but I just realised the previous reply question wasn’t from the other poster and you had not misunderstood what I’d said at all but were just posing another question, apologies for MY misunderstanding.

In answer to your question.... I don’t know, but you’ve got me curious so I am going to try it :). EDIT2, doesn’t work.

————————


Sorry, I meant that the mod wheel is set in that patch to raise the ‘amount’ on LFO4 which in turn is set to increase the amplifier envelope amount, which I believe is causing the amplifier to overdriven leading to the clipping of the signal,so just turning down the amp env amount won’t help if you’re using the mod wheel.

BUT...while turning them down certainly gets rid of it on mine, upon a further play I think Drive, which is set to 84, is actually the main culprit in that patch. Turn that off and it’s gone even if you leave the amp env at full.  If you want Drive in the mix then the amp env needs to be lowered and so does the mod 1 if you’re using the mod wheel.



« Last Edit: June 03, 2018, 04:20:00 AM by Frocktar »