quick question about input voltages

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slow_riot
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quick question about input voltages

Post by slow_riot » Sat Jan 30, 2010 8:20 pm

I have a motu 828 .

According to the output specification sheet, it outputs a voltage within -2.3 V and +2.3

Is it likely that this is the input range for CVs as well? I.e. do I need to use something to convert control voltages into this range to fit them into my computer?

thanks in advance

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doctorvague
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Re: quick question about input voltages

Post by doctorvague » Sun Jan 31, 2010 9:52 am

slow_riot wrote:I have a motu 828 .

According to the output specification sheet, it outputs a voltage within -2.3 V and +2.3

Is it likely that this is the input range for CVs as well? I.e. do I need to use something to convert control voltages into this range to fit them into my computer?

thanks in advance
It appears you are misunderstanding some basic concepts of how Volta works. Volta sends CV (via your interface of course). The only thing that needs to get sent back IN to the computer is audio- specifically the audio output of the oscillator you're calibrating. MOTU recommends using a sine wave or barring that a triangle wave. If the specs are correct for your interface you should get around 4.5 octaves of 1V/Oct tracking as you have potentially 4.6Vp-p.

Cheers
Phil

slow_riot
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Post by slow_riot » Sun Jan 31, 2010 10:29 am

Hi Phil. thanks for your answer

I'm not actually using Volta but it seems like this forum is the best place for discussing issues about getting CV to and from computers. I'm gonna be using Max/msp and hopefully using translated CVs in a number of ways inside that.

Anyways I'm not really familiar with voltage, and this point is confusing me. I think maybe I need to research voltages generally a bit more. Starting with the difference between polarized and non polarized voltage and when both are used or not.

It seems logical that a soundcard that outputs within a certain range would take inputs within that same range though.

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doctorvague
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Post by doctorvague » Sun Jan 31, 2010 11:37 am

slow_riot wrote:Hi Phil. thanks for your answer

I'm not actually using Volta but it seems like this forum is the best place for discussing issues about getting CV to and from computers. I'm gonna be using Max/msp and hopefully using translated CVs in a number of ways inside that.

Anyways I'm not really familiar with voltage, and this point is confusing me. I think maybe I need to research voltages generally a bit more. Starting with the difference between polarized and non polarized voltage and when both are used or not.

It seems logical that a soundcard that outputs within a certain range would take inputs within that same range though.
I suggest you ask this in the Silent Way forum. I believe he has done something more along the lines you're looking for and IIRC correctly figured out a way to get CV back in, but not really sure about that. That would probably be the place to ask - or maybe the software forum where there are people using Max/msp would be even better. Good luck!

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