DIY ribbon controller

[Mr_-G-]

Hi
I thought that I would share my DIY project. I made a ribbon controller with a ribbon potentiometer.
I used a ThinPot 200mm, 10KOhm connected to the Control Pedal of the NS2.
http://uk.rs-online.com/web/p/potentiometers/7081520/

This is what it looks like. It is very thin and comes with a sticky pad underneath (no, I haven't glued it to the red panel and I do not think I will ).

ThinPot used as a ribbon controller

ribbon1.jpg (48.57 KiB) Viewed 7380 times

I connected the cable this way: the middle connector of the ribbon goes to the TRS connector's tip (red here), the other two (shield [black] and ring [brown]) go to the other two connectors, depending if one wants to increase the resistance when moving to the right (black [top connector above] to shield and brown [bottom one] to ring) or to the left (just invert those). This is not too much of an issue with the NS2 as the morphing function can start "high" and end "low" or viceversa.

Ribbon controller - detail

ribbon2.jpg (25.58 KiB) Viewed 7380 times

Sorry the images are not high quality, they were taken with a webcam.
Is it fun? Yes, very much so. you can just press the ribbon in the middle and jump to a different setting (something you can't do with a rotary pot or a pedal).
I also got a 30 cm thinpot (they come in various lengths) to try and works fine too, but maybe even a 10 cm ribbon would be enough. A short ribbon might be handy to be positioned vertically next to the pitch stick. The two I have are too long for this, but the 20cm one could be located one the left side of the panel without interfering with the keyboard split LEDs.
Any questions, just ask.

[mjbrands]

Ooh, nice find

[cosmodrome]

That's a pretty great idea. By connecting it directly to the pedal port you don't need MIDI, so it's dirt cheap. I don't know if the Electro handles pedals the same way as the Lead does, but a Nord Lead/Rack will also send the values from the pedal controller via MIDI, so you get a full MIDI ribbon controller for nuts.
I guess I'll have a ride to the electronics store tomorrow...

[Mr_-G-]

I have been wondering whether one of those magnetic rubber sheets (used to make fridge magnets) would be good to keep the thinpot in place on the panel (so I do not have to glue it the red panel, but glue it to the magnetic rubber instead).

Does anybody have a feeling as to whether this is a *bad* idea? Maybe there is some magnet-sensitive stuff inside the NS2? (relays? I wouldn't have thought so, but maybe there is ...).

[Mr_-G-]

I just checked that if you connect both the control expression pedal and the ribbon in parallel with either a "Y" cable or one of these stereo duplicator adaptors:
http://uk.rs-online.com/web/p/audio-vid ... s/0392586/
then you can use the control pedal as normal and when fully down, still use the ribbon (so it allows to keep the pedal inserted and functional).

[cosmodrome]

Magnetism should be no problem at all. But it's not a very solid connection - it particularly won't help against forces parallel to the ribbon. I'd rather go with a strip of wide, clear adhesive tape and cut out the ribbon's sensitive area. It will get off without residues if you just warm it up a little with a hairdryer. It will also do a failrly good job protecting the connections of the thinpot against tension.

[Mr_-G-]

And here is what the finished gadget looks like:

Ribbon controller, finished.

ribbon3.jpg (29.32 KiB) Viewed 7187 times

Since the pot comes with a 3M sticky film, I glued it to a piece of plastic (painted red ) and used a crimp connector to attach the pot to the cable to avoid breaking the connection.

I ended up using a piece of thin, very weakly magnetised rubber sheet (under the plastic) held in place with double-sided sticky tape. It is very firmly in place (no, it does not slide when "playing" the ribbon) and the length seems OK as it does not really obstruct the buttons. The magnetic tape allows it to be removed at any time without worries of damaging the panel finish.
I checked and yes, it sends MIDI CC data out in both the Global and Extern channels (one would expect this anyway, as the ribbon is functionally identical to an expression pedal).

[mjbrands]

That, sir, is a nicely made gadget

[Mr_-G-]

Update: I've been experimenting a bit more with this "controller" and by adding a 47uF capacitor connected to the shield with a variable resistor (in series) to the tip (i.e. a passive low pass filter, like in the guitar "tone" knob, but with a much larger capacitance value to reduce the frequencies to be filtered). This allows to tune the speed at which the controller jumps from one value to another and results in a kind of legato or portamento effect with the controller. The exponential decay in the capacitor discharge makes the transition of values to change very smooth. The variable resistor controls the amount of low pass filtering, which results in a control of the speed of the transition. If anybody needs further explanation, just ask.

[Mr. Marko]

Wow, this might solve an issue I have with the Nord Modular G1.

When you have both the pedal and ribbon connected...does the pedal set the master level and the ribbon work with that as the low limit?

Is there a smaller version of this part?