Beads Cv

Hello. Today I received my Mi beads. I want to control all cv ins with my voltage block, it gives out +5v. I could not really find which control voltage the inputs from beads need. Is there a list or something? If 5v not fine I can use my Frap tools 321 to hopefully adjust the cv.
Thank you.

If you set the main knob to the minimum, and the attenurandomizer to the maximum, a CV of 5V will be equivalent to turning the main knob to the maximum – so the 0V to 5V range of the CV is mapped to the entire range of the parameter.

What happens if i send a +/- 5 v ?


Just kidding, but that’s exactly why writing “+/- X V” in the specs is misleading and vague: Are these maximum ratings? Is this the range to get a full sweep of the parameter? But isn’t it dependent on the position of the attenu•ators/verters/randomizers? And what about the value of the main knob?

So let’s say you are sending a triangle LFO going from -5V to +5V, the knob is at the minimum, the attenurandomizer set to the maximum.

Then, during the first half of the LFO’s period, when it goes from -5V to 0V, nothing will happen, the module will behave just as if the knob is set to the minimum - the CV can’t just turn it further CCW. During the second half of the LFO’s period, when it goes from 0V to +5V, this will be equivalent to turning the knob CW from minimum to maximum.

Thus, if you want the parameter to go from minimum to maximum, with a +/- 5V bipolar LFO you need to:

  • Set the main knob to the center.
  • Set the attenurandomizer around 3 o’clock so that the modulation is attenuated by 50% (you can identify this by ear, at the right spot there won’t be any plateau in the modulation).

Negative CVs turn the knob CCW, positive CVs turn the knob CW, and it takes 5V, without attenuation, to turn from end of the knob to the other.

A link to another long explanation of the same topic: How to MI Attenuverters Work? - #3 by Dasein1980


Hello Emilie.

Thanks for your answer. I am still in „finding out mode“ it seems that 0-5v works for cv input „dry/wet“, shape, pitch and density.

With the cv input time and size it seems like the „last 10% clockwise“ I don’t get, compared to the potis on the Modul itself. Do I need more control voltage there?

Possibly… Except for the pitch and density controls, the CV inputs are not calibrated, so they can have a little loss (5V will be read as if it was 4.95V on another input).

Ok, good to know. So it could be that I need 5.x V at max. But probably not more than 6v?

Hm, still don’t get it. And actually the „clockwise endposition“ via Modul poti. Time and size sound to me like the „middle position“ of booth. Is that possible?

:grinning: That’s what i thought !
Thank you very much for this clear answer.

Best advice is to spend a lot of time using the module… try different things with cv… make an educated guess at what’s happening and listen carefully to the results… eventually it will all click…

Thats a good hint, thx

That’s strange, can you post a photo of the module settings? Are you sure your CV source is sending those CV in the expected range (0 to 5V).

I will give it a try, once more and will come back in a couple of days. But yes, I am shure with the cv source. I am in a range of 0 to 5. I checked it with the multimeter.

Hello Emilie. Now I made some videos. For me it’s a little bit strange behaviour. Can I send it you via email? Or is it also possible here in the forum?
Thank you

Yes, please send the video to support@

Mystery solved!

When the SIZE knob is fully clockwise, the module is in delay mode. In delay mode, the attenuverter is repurposed as an EQ control, and the CV is added to it.

When the SIZE knob is not turned fully clockwise, it is not possible to push it towards that position (ie, enter delay mode) with a CV alone.

1 Like

Thank you, that helped a lot