Calculating the rate of lfo to match tempo

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Posted by G-Con on Jul-24-2007 15:53:

Calculating the rate of lfo to match tempo

Hi there.

I've got a virus ti and as much as i love it, it does have a few niggles.

One of which is that you can't automate the LFO rate when it is clocked to the bpm.

Does anybody know if there is a way of calculating what value to set the rate to so that it is in sync with the tempo.

Eg. My track is 130bpm. I want the LFO to cycle every 1/4bar. Is there a formula to work it out?

Posted by DiscoStew on Jul-24-2007 16:02:

Re: Calculating the rate of lfo to match tempo

quote:
Originally posted by G-Con
Hi there.

I've got a virus ti and as much as i love it, it does have a few niggles.

One of which is that you can't automate the LFO rate when it is clocked to the bpm.

Does anybody know if there is a way of calculating what value to set the rate to so that it is in sync with the tempo.

Eg. My track is 130bpm. I want the LFO to cycle every 1/4bar. Is there a formula to work it out?

I don't have a Virus TI (...yet), but I assume the parameter you can set is in milliseconds. If so, here's a good little widget to convert BPM's to milliseconds for different note lengths: http://www.macmusic.org/news/view.php/lang/en/id/3645/

The drawback to this widget is that it only goes up to quarter notes, but you can simply multiply that value out to get it to a bar, etc.

Posted by Sanguis Mortuum on Jul-24-2007 16:03:

Re: Calculating the rate of lfo to match tempo

quote:
Originally posted by G-Con Eg. My track is 130bpm. I want the LFO to cycle every 1/4bar. Is there a formula to work it out?

Well duh.

1/4bar = 1 beat (in 4/4)

60/130 = 1 beat every 0.461538462 seconds.

Posted by G-Con on Jul-24-2007 17:00:

Re: Re: Calculating the rate of lfo to match tempo

quote:
Originally posted by Sanguis Mortuum
Well duh.

1/4bar = 1 beat (in 4/4)

60/130 = 1 beat every 0.461538462 seconds.

so whats that in milliseconds

Posted by Storyteller on Jul-24-2007 17:08:

x1000

461 or 462 if you want it integer or rounded :P

Posted by G-Con on Jul-24-2007 17:17:

unfortunately the virus rate control isn't in milliseconds, its valued just from 0 to 127.

any ideas?

Posted by Sanguis Mortuum on Jul-24-2007 17:29:

Re: Re: Re: Calculating the rate of lfo to match tempo

quote:
Originally posted by G-Con
so whats that in milliseconds

Are you really that stupid?

quote:
unfortunately the virus rate control isn't in milliseconds, its valued just from 0 to 127.

any ideas?

Im not certain because I dont own a Virus, but from lookin at the PDF of the manual it sounds like you should be able to set the master clock of the Virus to a specific BPM then sync the LFO to it, not sure whether it can sync to MIDI clock too or not...

Posted by Zombie0729 on Jul-24-2007 17:35:

gcon i haven't needed to automate an lfo in clock mode yet but have you tried using an outside controller for it? cc value is listed in remote mode

Posted by DiscoStew on Jul-24-2007 17:42:

quote:
Originally posted by G-Con
unfortunately the virus rate control isn't in milliseconds, its valued just from 0 to 127.

any ideas?

0 to 127 is a midi data range. again, haven't used the Virus, but you may be in the wrong mode if you are seeing that range.

Anyway, for automation, it may be easier to do it via software. (Just a thought.)

Posted by G-Con on Jul-24-2007 19:28:

The virus's lfo's can be synced to the master tempo but can no longer be automated in this mode.

All the virus's values for every control is 0-127. I'm not in the wrong mode, this is how the virus is setup.

Cant do it in software because it wont allow the rate to be assigned for automation when clocked.

- I'm not sure what you mean. How will using an outside controller help?

Posted by Zombie0729 on Jul-24-2007 20:06:

quote:
Originally posted by G-Con

- I'm not sure what you mean. How will using an outside controller help?

Click on midi ctrl, and lets say your lfo is midi cc 85, just click on cc85 in the next box down, then draw in your envelope.

If you are trying to automate the lfo in the plugin this may be a problem, if that is the case then i would suggest creating another empty midi track and going midi out from your soundcard directly to midi in of your virus, with midi cables. This is the oldschool method that will bypass the plugin and should work.

sorry G-Con i'm not at home so i can't give you a step by step. i remember noticing the lfo couldn't be automated in clock mode so i'm doing a work around in my head. when i get home tonight i'll test this but you should be able to midi-cc it from an outside source.