Post your questions, opinions and reviews of the MPC1000. This forum is for discussion of the OFFICIAL Akai OS (2.1). If you wish to discuss the JJ OS, please use the dedicated JJ OS forum
By punkydoodle Tue Aug 20, 2013 11:05 am
hi,

i need a CV ( controlVoltage) source directly on my 1k.
My tought is:
if the Faders in the 1K are working with voltage i could make one fader beeing my CV source.
Or otherwise, is there a point within the MPC where i could tap +5V ( or 9V or 12V ) ?


the apllication:
i need to have a Pot or Fader, acting as CV source for my Modularsynth. ( sending a control voltage)
The Modular is then fed back via CV2Midi to my MPC.
I need to control/adjust things in the modular from as near to the pads as possible. (jamming )
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By sciguy Tue Aug 20, 2013 9:23 pm
m56p87 wrote:keep in mind even if you find a tap in there, the fader is probably not scaled to 1 volt per octave...


read that again...

It's just a linear potentiometer; it just outputs a variable voltage. It can't be scaled to 1v/oct, because it has nothing to do with any frequencies.


punkydoodle wrote:hi,

i need a CV ( controlVoltage) source directly on my 1k.
My tought is:
if the Faders in the 1K are working with voltage i could make one fader beeing my CV source.
Or otherwise, is there a point within the MPC where i could tap +5V ( or 9V or 12V ) ?


the apllication:
i need to have a Pot or Fader, acting as CV source for my Modularsynth. ( sending a control voltage)
The Modular is then fed back via CV2Midi to my MPC.
I need to control/adjust things in the modular from as near to the pads as possible. (jamming )


Just connect any potentiometer to a battery, boom, variable voltage output.
Or are you talking about having it record sequences and things, and play back the CV data?
If so, nope. I've never checked, but I can almost guarantee that the fader is just connected across the 5V supply, and the wiper pin of the pot goes thru an ADC to the processor. The processor handles what the fader is set to control, including recording motions, etc.
If you want to have recordable CV signals, you could try using one of the assignable outputs. Make a sample in Audacity or whatever that is just a DC offset, just a flat line at max amplitude from 0. If the MPC outputs are DC coupled (I'm not sure that they are), then looping this sample would just make the assignable out output a DC voltage. Changing the volume of the sample changes the voltage. You can then record qlink automation on the pad volume. (If the outputs are instead AC coupled, then you wouldn't be able to output a steady DC voltage; it would decay back to 0 over time)
User avatar
By Funkydrops Wed Aug 21, 2013 9:34 am
sciguy wrote: If you want to have recordable CV signals, you could try using one of the assignable outputs. Make a sample in Audacity or whatever that is just a DC offset, just a flat line at max amplitude from 0. If the MPC outputs are DC coupled (I'm not sure that they are), then looping this sample would just make the assignable out output a DC voltage. Changing the volume of the sample changes the voltage. You can then record qlink automation on the pad volume. (If the outputs are instead AC coupled, then you wouldn't be able to output a steady DC voltage; it would decay back to 0 over time)


Serious Hacking Right There. (black) Hat Down.
User avatar
By tapedeck Wed Aug 21, 2013 4:15 pm
i have tried outputting dc signals for some light controllers i built, and the mpc filtered them out pretty heavily.
i generated the dc signals in audacity, and transferred them via CF to the mpc (totally digital).

it did not work.

i got better results using noise bursts.

fyi.
By punkydoodle Wed Aug 21, 2013 9:18 pm
sciguy wrote: Or are you talking about having it record sequences and things, and play back the CV data?

no, not meant to deal/record with CV within the MPC.
1V/oct is also no question

sciguy wrote: ...... but I can almost guarantee that the fader is just connected across the 5V supply, and the wiper pin of the pot goes thru an ADC to the processor.

GREAT !
that was what i was hoping for.
so i just could tap this voltage coming from the fader i guess........
then patch to a buffered multiple, and work with that CV in the modular parallel with what i control/jam in the MPC.

you say there is a 5V suply ? thats then the other thing i hoped.
anybody has by coinsidence instructions or pics where exactly i have to tap ?
i would like to tap the 5V directly too. need also to install a Pot or two for sending CVs out.
.......i´l see :lol:
great news, Much thanks !


edit:
i was into DIY, built me a DIY modular,
but still don´t like to deal with power/voltages and such,
and still don´t understand any electronics :lol:...its now anyway a few years back