KVR Audio

emersonrailroad · Post by **emersonrailroad** » Mon Dec 12, 2011 1:58 pm

I accidentally posted this in the Synth forum a moment ago, but now I've found the proper place.

I am looking to buy 2 potentiometers that can be used in a midi controller I'm building. They will be used as selector knobs, so they need to turn endlessly and they preferably need to be notched as you turn them. I would need them to be standard sized, as in, having the same size as a standard guitar actuator. Could someone point me in the right direction or send me a link?

Thanks*

whyterabbyt · Post by **whyterabbyt** » Mon Dec 12, 2011 2:07 pm

If they're used as selector's arent you talking about a rotary switch?

emersonrailroad · Post by **emersonrailroad** » Mon Dec 12, 2011 2:18 pm

Yes, a rotary knob. I already have 12 guitar style potentiometers to use for adjusting perimeters, but I can't seem to locate some that turn endlessly (as they do on most midi controllers). The ones I found, for instance, only turn 300 degrees, which is fine for what they will be used for, but not for endless scrolling.

jupiter8 · Post by **jupiter8** » Mon Dec 12, 2011 2:28 pm

From the other thread (Dear God multiple threads are annoying) which was in the right forum BTW.

jupiter8 wrote:http://iteadstudio.com/store/index.php? ... alch7d5b46

http://www.aliexpress.com/product-fm/49 ... alers.html

Do note that endless rotaries aren't actually potentiometers. They're digital devices so you'll need a micro controller to get the data. A simple ADC won't work.

emersonrailroad · Post by **emersonrailroad** » Mon Dec 12, 2011 2:33 pm

Thank you. Your info is very helpful.

jupiter8 · Post by **jupiter8** » Mon Dec 12, 2011 2:41 pm

What kind of controller chip are you planning on using ? Arduino ? The Doepfer DIY kit ?

emersonrailroad · Post by **emersonrailroad** » Mon Dec 12, 2011 3:21 pm

I am using the Doepfer USB 64

jupiter8 · Post by **jupiter8** » Mon Dec 12, 2011 3:38 pm

emersonrailroad wrote:I am using the Doepfer USB 64

I see. As far as i can tell that won't work with endless rotaries.

emersonrailroad · Post by **emersonrailroad** » Mon Dec 12, 2011 3:49 pm

Thank you. I looked it up and you are correct.

Meffy · Post by **Meffy** » Mon Dec 12, 2011 6:22 pm

Please don't post multiple threads on the same topic. I moved your first thread to the Do It Yourself forum, which is the right place for it. I'll move this one there too and lock whichever has fewer replies. [edit: Deleted it instead since the only posts were yours and one reply that jupiter8 has duplicated here.] If you do post in the wrong forum, instead of making another thread just send a PM to me or any moderator and we'll move it for you.

emersonrailroad · Post by **emersonrailroad** » Mon Dec 12, 2011 11:17 pm

Meffy wrote:Please don't post multiple threads on the same topic. I moved your first thread to the Do It Yourself forum, which is the right place for it. I'll move this one there too and lock whichever has fewer replies. [edit: Deleted it instead since the only posts were yours and one reply that jupiter8 has duplicated here.] If you do post in the wrong forum, instead of making another thread just send a PM to me or any moderator and we'll move it for you.

I won't post multiple threads. It was a simple mistake and then I was unable to delete it.

Thanks everyone, for your advise.

Meffy · Post by **Meffy** » Mon Dec 12, 2011 11:21 pm

No trouble, different forums handle that kind of thing in different ways. Just PM a mod if you do need a thread moved.

jupiter8 · Post by **jupiter8** » Mon Dec 12, 2011 11:58 pm

I thought it was odd that there are no endless potentiometers (since all you need is to remove the endstop) and went looking and there are endless potentiometers! Found one called Piher N15 but where to get one i haven't got a clue.

flynsk · Post by **flynsk** » Tue Dec 13, 2011 12:13 am

Do you mean encoders? On a midi controller, the knobs you can turn around and around are usually encoders, not pots. they click too.

justin3am · Post by **justin3am** » Tue Dec 13, 2011 12:26 am

Some encoders click, some don't. I've never come across and endless pot (they call it a 'position sensor') before, interesting.
jupiter8 is correct, encoders work based on increment decrement logic, different models will have varying 'pulses per rev' resolution anywhere from 3 pulses/rev to thousands. You need a micro to turn these increment/decrement pulses into values. We use PIC or Holtek processors (some Holtek chips also contain an on-board MIDI codec), typically.

looking for Potentiometers