Build Your Own Clone Message Board

Introducing, the new and improved SILENCE, YOU FOOL!!!

This is a remake of my first pedal, which was called Vader. Hence, this one is called The Emperor.

The Name is far more impressive than the function: this is simply a secondary volume level that you can preset and then stomp on and off as needed. I got everything but the expendables (wire/solder) from Mammoth. Black textured enclosure. And world-class spaghetti wiring

My favorite thing about this piece of junk (apart from the classy black and silver exterior) is the bicolor LED. I wired it into the second channel of a duel-gang pot that I used for the volume. Basically, as volume increases, the LED goes from red to violet to blue. I haven't seen that feature on a pedal before, and I must say that I positively love it. I can tell approximate volume level just by glancing at the LED.

Anyway, I've done enough gabbing. I don't actually complete a pedal very often so when I do it's a rather momentous accomplishment for me Here are some pics:

Slick!
I dig the stealth bomber look.
LED trick is wicked.- where the hell did you find a red/blue led, all I've ever seen are boring ol' green/red.

Cool! Dont let George Lucas get ahold of it or he'll completely fuck it up.

Mammoth!! They updated their stock list recently.......

That's awesome! Electric tape for the win!

And seriously, +1000 on the led trick, super cool, coolest little trick that i've seen in a while!

Ya, +1 on the LED trick, totally stealing that one! Too bad they dont make dual gang clear shaft pots!!!!

awesome LED maneuver!!

This build would go nicely alongside my 'Imperial Sagulator'.. join the Dark Side!


Oh and I love your new Avatar.. that's my cat every morning..

Thanks! My cat looks (and acts) exactly like the one in the avatar, which is why I got it. It's actually a T-Shirt from [url]shirt.woot.com[/url] that I turned into an avatar because it was so funny.

What they should do is make a glowing pot with my LED effect built in

Totally should have learned to google before i assert by now! So I found these http://ca.mouser.com/ProductDetail/Alpha-Taiwan/RV142F-40-35BL-A5K/?qs=sGAEpiMZZMuarXojuOTsczmsK%2fu4Q6ul0QwQ7LIY9RI%3d, they are "Dual" clear shaft pots, but is that the same thing as dual gang, should there not be 6 pins instead of 5 if that was the case? The data sheet on these has no info on the pinout. Anyone know what the scoop is?? If they are indeed dual gang, then color changing knobs coming up!!!

I have two thoughts. Either both "gangs" share a center pin, which wouldn't be conducive to color-changing knobs, or the clasps on the side of the pot are the other center pin. Maybe I'll purchase a few and experiment

A final thought is that the pins on duel-color LEDs are a bit harder to manage than on single color, so it might a be a bit tricky to get them inside the pot, but it's probably possible. The builder might have to insulate the pins

Anyway, definitely a neat idea

Ok, well after a bit more digging it looks like Crankston your first guess was right, dual gang pot with a shared ground? Crankston, to you mind posting a quick description or diagram of how you have the LED and pot wired up currently. I am still a bit of a lego builder when it comes to the electronics side of things so I always seem to understand better when i can see things.

I must say, that's a pretty useless pot configuration in my book. If you have a circuit that can use a shared ground, it's just as easy to use a single-gang pot. Oh well.

Here is my basic schematic.

The upper right hand corner is my best ( ) representation of a duel gang pot with one set of lugs set aside for audio and the other for the LED. You run the center pin of the LED through a resistor and then into ground (by way of a stomp-switch on my pedal). Pins one and three on the LED each control one color. You then attach the center pin on the pot to +V, and pins one and three to pins one and three on the LED, respectively. In a nutshell, when the knob on my pedal is turned clockwise, the pot diverts power from the red LED pin and into the blue LED pin.

Thanks for posting that wiring! I was just working it out on the breadboard, and I had come to the same layout as yours (after frying the first LED ).

However, I only have some diffused Red/Green & Red/Yellow bi-color LEDs on hand, and what I'm getting is a dead spot in the middle of the rotation. Both colors are lit, but so dim, there's no perceivable color at all.

Since everything else seems consistent with your layout, I'm led to believe that a) diffused vs. waterclear matters, or b) the colors matter. Just thought I'd post my results..

Wow! I did'nt came back to look in here, forgetting that led trick, but there's seriously something hot to dig out of those dual gang clear shaft pot.....

Ducty, it will end with another run of daughter boards and dual gang pots!

Very nice Crank.

And leave it to Dave to dig out something new for us !

LOL I Almost fried my first LED but got lucky

The thing about this schematic, like you noticed, is that when you get to the middle of the turn, both LED's get so little power that the color gets very dim. In effect, all that a bi-color LED consists of is two LED's in the same piece of plastic. The problem with diffused is that they let less light through than a non-diffused. This can be good if you want six different very specific shades of red, because if the LED is tinted, it only lets one very small spectrum of light through, and the rest is reflected back by the plastic encasing and turned to heat (ever notice how a diffused LED can be easier to fry than a normal one?).

In Short, my setup has the same problem that yours does, but because your LED's are diffused, they don't let the whole range of light through, only one or two specific channels. This makes the problem much more noticeable.

If you notice in my picture when the pedal had a violet-colored LED, the pot isn't in the middle, it's more to the red side, because I have the same problem that you do: albeit mine is probably a bit less magnified.

It might be conceivable that the colors also matter to some degree, simply because some colors (Blue and Green) get brighter than other colors (Red and yellow).

There's definitely some experimentation to be had!!

I have one more thought!!

Let's say that you're building a simple two-knob fuzz box. You can use two duel-gang pots, and have each control one color on a bi-color LED. Thus, by one glance at the LED, you don't just find out your volume, but your approximate volume AND fuzz at the same time!!

Did some more digging last night, and just got myself more confuzed. The 5 pin clear shaft pots are definitely dual gang, and definitely share one pin between the two gangs, but I cant figure out which one is the shared one. All the data sheets I can find only have info on the physical dimensions, nothing on pin out. I am thinking I will have to just order a couple to try out.

hmm, okay. let's throw function out the window for a sec and work on this brightness problem. Let's say you were to devote the whole dual gang pot to the LED situation (useless I know, but hear me out).. could you parallel the CLR with the resistance of the other 'gang' of the pot, such that in mid-rotation, the resistance is reduced? (thereby giving the middle part of the sweep more brightness?)

I don't know where this would get us, just trying to push the idea along

That's definitely a good thought. What if we used the Pot in conjunction with a few transistors and resistors? I'm going to work on that.........I'll get back with something in a bit.......

EDIT: Okay, so I'm using an A500K pot. I don't know what size PowerPopGuy is using. To my understanding, that means that when the pot is in the middle of it's cycle, pins 1 and 3 are each getting voltage through 250K of resistance, which doesn't leave much for either LED. What if we wired two resistors of slightly less value onto the pot? One would go from pin 1 to pin 2, one from pin 2 to pin 3. We might also have to slap in some diodes so one LED doesn't yank voltage from the other? All that would do is give a constant, set voltage to each LED. When in the middle, both LED's would be brighter. When on one extreme, both LED's would still be glowing, but one would have a lot more voltage than the other. Any thoughts on this

Getting more interesting by the second I'm using A100K as per your diagram. I just put resistors between pins 1&2, and pins 2&3. (let's call them 62K, though I tried several values) Still gets dimmer, but less so, even with my diffused LEDs.

Then I added two 1N914 diodes in parallel with those two resistors. (stripes/cathodes facing the LED's anodes). Now there is a constant brightness, and the color change is instant, not gradual. Downside- the color change is all bunched up at one end of the rotation. (due to the Audio taper maybe?)

Gee I'm having fun though! Too bad I have to go to work now..

Nice R&D!

I'm a bit unsure of your circuit. Is it something like this?

yeah, I'd say that looks just like what's on my breadboard currently. the CLR i'm using on the LED's common cathode is around 1K I think..