Delayed Vibrato Help Needed!
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Author:  Kyhotay [ Mon Oct 31, 2011 11:43 am ]
Post subject:  Delayed Vibrato Help Needed!

Hi Scott,

I was attempting over the weekend to add a delayed vibrato to a Flute patch. I thought running the 4700 LFO through a VCA with a slow attack would work. It didn't: instant vibrato despite any settings of the ADSR. I tried the decoupling caps on the 4700 power supply, the inverter...I even tried running the LFO through my ARP 2600 lag processor to see if that would do anything useful. It didn't. Since the Flute part was being controlled by my MIDI>CV, I just manually increased the LFO output to the VCO. But isn't that what voltage control is for???

I have 2 dual 4700 cabinets with plenty of modules. Any suggestions on getting delayed vibrato that I haven't thought about? While we are on the subject, what would be the process on the 9700?


Author:  James [ Mon Oct 31, 2011 6:30 pm ]
Post subject:  Re: Delayed Vibrato Help Needed!

this site has some great basic patching info and includes some vibrato and modulation patches. Might be worth a look. ... synth.html

Author:  Kyhotay [ Mon Oct 31, 2011 7:57 pm ]
Post subject:  Re: Delayed Vibrato Help Needed!

Thanks James,

I saved the article to review in depth later. The part about advanced uses of VCA's (5.33) is close to what I was doing: If we add a second vca and eg to the modulating signal, we get a vibrato that varies over the length of the note. This feature can be added to any of the modulations for a process refered to as DYNAMIC MODULATION.

The patch was showing, in this case, a LFO going into a VCA, controlled by an EG and the VCA output controlling another VCA which was modulating a VCO. More like VC Tremolo than vibrato. What I was trying to do, without success I might add, was the same patch, but going into the VCO along with the pitch CV. That makes sense in my alleged mind but somehow the analog gods are not in agreement.

Brian Folkes

Author:  PAiA-Scott [ Tue Nov 01, 2011 10:11 am ]
Post subject:  Re: Delayed Vibrato Help Needed!

Going into the 2720-1 VCA, you'd need to also connect some negative CV to one of the other control inputs to effectively shift the LFO control down. Then as the envelope control occurs, its positive control will counteract the negative control and you'll get the LFO at the output.

On the 9741 VCA, the panel control works to provide the negative offset.

It won't take very much LFO for a vibrato effect so it might be necessary to attenuate it some too.

Author:  Kyhotay [ Tue Nov 01, 2011 5:08 pm ]
Post subject:  Re: Delayed Vibrato Help Needed!

Of course! Negative voltage. I figured it had to be something simple I was missing.


Brian Folkes

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