Asys LFO reset - is there a trick to this?

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Rozzer
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Asys LFO reset - is there a trick to this?

Post by Rozzer » Tue Nov 10, 2009 8:08 am

Can anyone with an Asys RS-85 LFO explain to me how to get the Reset-IN working?

What I want to do is feed it a trigger so the LFO phase resets on every trigger, for predictable vibrato and similar effects. Instead I get all sorts of unpredictable behaviour. Mostly the triggers are ignored. I've tried lengthening the triggers to gate lengths and then the LFO seems to pin to a certain value and stops oscillating altogether.

If I feed the Reset a square wave from another LFO then the Reset seems to work more like a Sync. The two LFOs will oscillate in time, but this isn't the result I'm after.

I've tried allsorts, passing the trigger through a preamp, inverting it, shaping it. Nothing seems to work.

Anyone got one and figured out how to trigger a phase reset?

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Re: Asys LFO reset - is there a trick to this?

Post by bubblesound » Tue Nov 10, 2009 11:06 am

Rozzer wrote:Can anyone with an Asys RS-85 LFO explain to me how to get the Reset-IN working?

What I want to do is feed it a trigger so the LFO phase resets on every trigger, for predictable vibrato and similar effects. Instead I get all sorts of unpredictable behaviour. Mostly the triggers are ignored. I've tried lengthening the triggers to gate lengths and then the LFO seems to pin to a certain value and stops oscillating altogether.

If I feed the Reset a square wave from another LFO then the Reset seems to work more like a Sync. The two LFOs will oscillate in time, but this isn't the result I'm after.

I've tried allsorts, passing the trigger through a preamp, inverting it, shaping it. Nothing seems to work.

Anyone got one and figured out how to trigger a phase reset?
it sounds like the Asys LFO needs a bi-polar input for the sync/reset. you could probably use the trigger pulse you're trying to use if you level shift it to +-5V. there is a doepfer module that does level shifting, but i'm not sure what the model number is.
i've tried nothing and i'm all out of ideas...

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Post by Rozzer » Tue Nov 10, 2009 12:17 pm

Thanks bubblesound. Yeah that did occur to me. I have an Asys Shifter which add or subtracts DC signal to any input, so presume I could achieve the same thing. I have tried passing the trigger though it at various settings. No dice though.

I have asked Bob Williams of Asys, but he's just shipped his system to the US for NAMM, and hasn't got anything to test on. I'm sure he'll get back to me soon. Was just wondering if anyone had any direct experience in the meantime.

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Karl Jeffers
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Post by Karl Jeffers » Wed Nov 11, 2009 9:58 am

The RS-85 resets when a positive voltage is on its input. And as long as there is voltage on it it stays in reset mode. So you could use an envelope to change the gate to a short trigger, or any other kind of module that can do that.

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Post by Rozzer » Wed Nov 11, 2009 12:11 pm

Thanks Karl - the output from the midi>cv is already a trigger (you can switch between gate and trigger outputs).

Your post did lead me to try an envelope output as the trigger instead, and it worked within certain parameters. Unfortunately if the envelope decay is too short, the LFO won't register it, which is perhaps why using a proper trigger didn't work. Also, the reset only seems to work within certain frequencies of the LFO. So at very low frequencies the reset gets ignored. Shame, as I was hoping to be able to make reproducible drones using long LFO times.

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Post by Karl Jeffers » Thu Nov 12, 2009 8:14 am

Last night I tried it and mine behaves just like you said.
You could use the RS-95 as LFO with reset, but that has some quirks to if I remember correctly.

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Post by Rozzer » Thu Nov 12, 2009 8:49 am

Karl Jeffers wrote:Last night I tried it and mine behaves just like you said.
You could use the RS-95 as LFO with reset, but that has some quirks to if I remember correctly.
Thanks Karl. Yeah I've been using the rs-95e which seems to work a lot better for my purposes. It resets at any frequency using only a trigger, which is great, except that uses up a precious oscillator, and the frequencies don't go as low as the LFO.

I think I'll have to invest in a different LFO. Anyone know of one that will reset properly even at really low frequencies?

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Post by hogberto » Thu Nov 12, 2009 4:54 pm

Rozzer wrote:…
I have asked Bob Williams of Asys, but he's just shipped his system to the US for NAMM…
[thread hijack]

holy crap is Winter NAMM around the corner already??? :nana:

[/thread hijack]

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