rodneon

The fix is actually easier than I thought. I figured it out, after much fiddling... all you have to do is swap the wires between tip and ring. That's it. So I answered my own question, but the info is here forever, if anyone ever runs into the same problem.

It may not be the easiest way, but it wouldn't be too hard to engrave a notch in the pot's shaft and come up with a little spring mechanism that would click when the pot is centered. All you really need is a little click, so any little spring mounted onto the back of the panel should do the trick, if you bend it just right. Good luck!

I'm fairly new to electronics, so bear with me. Can I apply the parallel resistance formula to solve this problem? I mean: Re = (R1 * R2) / (R1 + R2) 8 = (50 * x) / (50 + x) x = 9.524 Kohms Which would mean a 10 Kohm resistor in parallel with the tip and ring would solve the problem. Right? Wrong? Any input would be much appreciated.

I recently bought a Yamaha FC7 pedal to use with my Roland A-33, which will eventually be part of a MIDIbox setup -- so this isn't completely off-topic ;) The problem is, the resistance values don't match. According to a technician at Sweetwater: The Yamaha FC7 manual states that the resistance between tip and ring is 50Kohm, the same between tip and shield. However, there doesn't seem to be a "trim pot in-line with the shield", which probably doesn't matter much here. I wouldn't give the feel of that pedal for anything, especially for those crappy, cheap-feeling Roland pedals. Is there any way to "convert" the tip-ring resistance range of the Yamaha pedal from 50Kohm to 8Kohm?

Another option, which is what I would do if I were to build a LEDring, is to make a plastic mold. I haven't tried this, but it's an idea... I'll try to describe the method using words: 1. Draw (or print) the arrangements of the LEDs and center hole on a piece of acrylic foil, like those used for overhead projectors. 2. Drill a hole in a fairly thin piece of wood the exact size of the whole piece (in other words, a big circle around the LEDs). 3. Carve or find a cylindrical piece the same size as the center hole for the encoder/pot. Something tells me that the game pieces in the old board game Risk would be perfect, but I'm not sure. 4. Using stick glue or a very thin layer of school glue, attach the LEDs to the acrylic foil -- you'll have to use LEDs that are flat on top, of course. Do the same for the cylindrical piece. 5. Using the same method as above, glue the acrylic sheet onto the wooden mold. Now you should have an exact negative copy of the "missing piece of the puzzle". 6. Pour any kind of liquid/malleable polymer into the mold. I would think that the caulk used to seal bathtubs and shower door rails would be okay to use. Even glue, paint, or clay might work. 7. Wait for it to dry and peel the acrylic sheet off the wooden mold. With a small blade, like a scalpel or an Exacto knife, remove the final piece from the mold. There you have it! If anyone tries this, let me know whether it works... or not! I'm not responsible if it doesn't though... ;)

That's kind of what I was thinking. It's pointless though, since you can use encoders. The thing I don't like about encoders is not being able to actually see and feel where the parameters are when you change patches. LEDrings take care of the visual part of the problem, but it seems like they use too many physical resources (i.e. 12 DOUT pins for 11 LEDs, and that's only one parameter). It appears to me that, while a motorized knob would be costly, it would require less resources from the DOUT or AOUT modules. Implementing a motorized knob should actually be fairly simple, conceptually anyway. The code would be "knob is at x. new value is y. motor turns counter/clockwise, until knob is at y". Sounds simple to me, but being new at this and never having built a MIDIbox myself, I wouldn't know how to implement such feature. It sure would be neat to see a MIDI-controlled Minimoog, driven by a MIDIbox, have all its knobs move to their correct position when a patch is called upon. :)

That is exactly what I was looking for -- a much more elegant solution to the LEDring problem. Thank you so much for the link!

You're right. Even the one I pointed out would be too slow (300 degrees/sec).

Has anyone tried using a motorized knob in their MIDIbox? Alps is the only manufacturer I could find that makes them: http://www.potentiometers.com/alps_rotary.cfm#motor (look at the RK25T model) Would that kind be compatible with the MIDIbox? If so, how could it be implemented? I could be wrong, but it doesn't seem like those are available to hobbyists. Bummer! Would it be possible/viable to make one "home-made", using a stepper motor?

Has anyone peered inside any of these commercially-available controllers to see what their LED rings look like? I couldn't find any info about any companies selling ready-made LED rings. I suppose it's not that hard to make a 9-, 11- or even 15- segment LED ring, but this 31-segment one takes the cake: http://www.plugzilla.com/press/photos/fp_limited Someone has to be making those custom for Plugzilla, as I haven't seen that kind anywhere else. Is there a way to build a "LED ring module" to use with the MIDIbox? I mean, something that wouldn't require so many pins from a DOUT? Some kind of multiplexer, maybe? I'm new around here, and I haven't build a MIDIbox yet, but I'm really interested in the visual and functional aspect of controllers and such, that's why I'm just baffled by the LED ring concept.

I connected my Korg MS2000 to Traktor once and I'm quite positive I used the Pan knob to do exactly what the jog wheel is supposed to do: rewind and fast-forward through the track as it's playing, at higher speeds the farther you go left or right. I don't use Traktor anymore so I can't test it. But, if I'm right, then the MIDI message should be just a standard CC, assigned to the appropriate control in Traktor. The values transmitted would then be as follows: Hard left=0; 9; 18; 27; 37; 46; 55; Center=64; 73; 82; 91; 101; 110; 119; Hard right=127 Good luck!

I like that idea. It may be way more work than I'd be willing to put into this, but it's definitely a possibility.

Wait! I just answered my own question. According to the Quantum Research Group website... I just gotta find out how to do it. Then I'll make millions and take over the world!!! ;D Sorry.

Don't discard that idea yet! I kinda like it. Does this slider use the same technology as the ribbon controllers found, for example, on the Kurzweil K2600, Roland AX-1 or Korg Triton? I have posted questions/suggestions about a motorized organ drawbar controller, but a slider-based organ controller would be much more interesting both visually and functionally. In an application such as this, the resolution doesn't need to be any higher than 8 or 9 steps, so 128 would be more than enough. I only wish the touch slider was transparent, so you could put 8 LEDs underneath it for an even fancier look! Any ideas on this? By the way, speaking of Kurzweil, the ribbon controller on the Kurzweil is a really long one. Is there a way to make a ribbon controller from scratch? Better yet, a transparent one? :)

I'm not sure yet, but I like the idea of having the LEDs sticking out of the panel just a little. I downloaded Eagle today and came up with a PCB layout for one LEDring, but something happened and it didn't get saved... :P Even though a 2-layer solution may be more logical, it looks like the design is possible using a 1-layer board. You'd need a ribbon cable going from the board to a "distributor board", which in turn is connected to the DOUT module. It maybe a bit too much, but it seems like a more elegant solution to the LEDring problem than just wires soldered to the LEDs glued to the frontpanel. Well, those tiny LEDs sit flush and flat against the PCB. It means you'd need a PCB *just* for the LEDs, with holes drilled for the encoders which would sit on a bord underneath the LEDring board. That may not be the most economical idea, but I might consider it. But hey, I've seen some excellent designs in here that look great on the outside and are a rat's nest inside, so who cares? ;) I just have a tendency to be extra picky, so bear with me -- I used to go to school for graphic design...