Random LFO Shape Wave Reset Bug?

The Dave Smith Instruments Pro 2 Analogue Synthesizer

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eisblau
Posts: 13
Joined: Fri Aug 01, 2014 8:00 pm

Random LFO Shape Wave Reset Bug?

Post by eisblau » Mon Jan 25, 2016 10:55 pm

When you choose LFO waveform random and put a wave reset on each key, the modulation does not have any effect. The LFO still behaves like "free running". It should modulate on each key I hit with another new value, for example for filter modultions of percussive sounds. On all other synths I know the LFO key trigger works with random (s+h) values right on the start of the sound.

Can somebody confirm this?

eisblau
Posts: 13
Joined: Fri Aug 01, 2014 8:00 pm

Re: Random LFO Shape Wave Reset Bug?

Post by eisblau » Tue Jan 26, 2016 7:22 pm

PS.: What workaround could be done? A different random value on each keystroke, how to accomplish this in the mod matrix?

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chysn
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Location: Metropolitan Detroit

Re: Random LFO Shape Wave Reset Bug?

Post by chysn » Tue Jan 26, 2016 9:24 pm

Don't have a Pro 2 (yet?), but I'll give you the workaround I used with my Mopho once. The goal was to have a random modulation amount for every keypress, so I set the LFO to random, and gave it the slowest-possible frequency. I think that the period was about thirty seconds. So as long as my notes were held for less time than that (and of course they were), I got the random-with-each-key to work fine.
DSI: Evolver #1431, previously Mopho Keyboard and Desktop Mopho
Hardware: Moog Little Phatty Stage II (Red), Arturia MicroBrute, Korg Volca Beats
DAW: Reaper for OSX through PreSonus AudioBox USB

eisblau
Posts: 13
Joined: Fri Aug 01, 2014 8:00 pm

Re: Random LFO Shape Wave Reset Bug?

Post by eisblau » Wed Jan 27, 2016 12:45 pm

This is exactly the problem. Even on a really slow LFO frequency and with different reset phases, the first LFO value has no effect when key sync is on - the LFO puts out always the same non-random start value. With keysync (wave reset) off, the LFO modulates independent from the pressed keys.
Last edited by eisblau on Wed Jan 27, 2016 2:05 pm, edited 1 time in total.

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chysn
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Location: Metropolitan Detroit

Re: Random LFO Shape Wave Reset Bug?

Post by chysn » Wed Jan 27, 2016 1:15 pm

Yeah, that's weird. What if you keep it super-slow, but turn off key sync? Will the occasional transitions ruin the effect you're going for?

Edit: Forget I said that. It's probably the value staying the same on a subsequent keypress that would ruin the effect.
DSI: Evolver #1431, previously Mopho Keyboard and Desktop Mopho
Hardware: Moog Little Phatty Stage II (Red), Arturia MicroBrute, Korg Volca Beats
DAW: Reaper for OSX through PreSonus AudioBox USB

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chysn
Posts: 863
Joined: Sun Aug 08, 2010 6:26 pm
Location: Metropolitan Detroit

Re: Random LFO Shape Wave Reset Bug?

Post by chysn » Wed Jan 27, 2016 1:29 pm

Does it seem like the Random LFO shape starts at zero for a full cycle before changing to a random value? I wonder if it would help to play with the phase? If you put it at an offset of 359 degrees (or a phase value of 126), perhaps it'll get off the zero value and into the next random value almost immediately.
DSI: Evolver #1431, previously Mopho Keyboard and Desktop Mopho
Hardware: Moog Little Phatty Stage II (Red), Arturia MicroBrute, Korg Volca Beats
DAW: Reaper for OSX through PreSonus AudioBox USB

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