RGB Pedal

PelliX

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Just a random idea, but wouldn't it be funny to make an "RGB LED" pedal. Maybe back to back RGB LED's or just a single one. Obviously use them for clipping and have a gain control for the R, G and B channels as it were. A user could also dial in specific settings simply by remembering a colour instead of knob positions.
 

GustHFS

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The closest I've seen to something like that is my own old Digitech JamMan Solo loop pedal. The main central LED changes color according to the function of the pedal (red for REC, green for PLAY and yellow for OVERDUB). Anyway for the age of the pedal that doesn't seem to be an RGB led, maybe it's a multicolored one.

Gust
 

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PelliX

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The closest I've seen to something like that is my own old Digitech JamMan Solo loop pedal. The main central LED changes color according to the function of the pedal (red for REC, green for PLAY and yellow for OVERDUB). Anyway for the age of the pedal that doesn't seem to be an RGB led, maybe it's a multicolored one.

Gust

I was thinking about actually using the LED channels as the clipping or whatnot in the pedal. Each colour has a different forward voltage, which defines the clipping. Say you like the red LED clipping with some blue, but not the green, then you would select a mix that gives you a reddish purple sort of tint.

All just mental doodling, no actual plans to knock something like that up, honestly. I'm not that hot on diode clipping in general.
 

GustHFS

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I was thinking about actually using the LED channels as the clipping or whatnot in the pedal. Each colour has a different forward voltage, which defines the clipping. Say you like the red LED clipping with some blue, but not the green, then you would select a mix that gives you a reddish purple sort of tint.

All just mental doodling, no actual plans to knock something like that up, honestly. I'm not that hot on diode clipping in general
I have some experience in building pedal clones (most of them drives), with LEDs as clipping diodes. But unfortunately I don't have enough knowledge to the point of creating a circuit where a RGB LED itself emits a specific color according to the degree or type of clipping. In fact, I don't even know if that would be possible, because I've read somewhere that LEDs of different colors and sizes have different behaviors in a drive circuit. I don't know if I help in your conjectures or if this is really what you're looking for, but it's as far as I can get, LOL.

Gust
 
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PelliX

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I have some experience in building pedal clones (most of them drives), with LEDs as clipping diodes. But unfortunately I don't have enough knowledge to the point of creating a circuit where a RGB LED itself emits a specific color according to the degree or type of clipping.

Well, when you use a LED for clipping, it can light up of course - so what I was thinking of was using the resulting "blend" as "the colour" of the preset as it were. If that makes sense.

In fact, I don't even know if that would be possible, because I've read somewhere that LEDs of different colors and sizes have different behaviors in a drive circuit.

Exactly, the forward voltage is quite different depending on the colour of the LED. In most RGB LED's (which are really just three LEDs in one package) this is compensated, but not always. The differences between them are exactly what would make it worthwhile to 'blend' among them - or so I was thinking. To 'blend' it would just be a matter of determining an amount of signal per "LED channel". This could be done with a knob per channel, reducing the resistance on that colour/channel and thus passing an amount of the dry signal through it. Of course one would end up with 3 channels and depending on the 'mix' the LED (referred to in singular for clarity's sake) would exhibit a specific colour.

Maybe I should pop something together on a breadboard if I get bored sometime.
 

TheKman76

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OK, are we talking parallel clipping stages, one colour each and mixing together? Or are you thinking of using all three colours in a single stage somehow? Or, some other topology I haven't imagined perhaps.

And more to the point, how do you think Teal clipping will compare to Puce clipping? 🤔
 

PelliX

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OK, are we talking parallel clipping stages, one colour each and mixing together?

I guess that's more or less what I had in mind. Set the desired "level" per channel and the resulting mix would exhibit a given colour - provided enough signal is present. Of course, without any compensation one colour would 'kick in' faster than others, but that also gives one control over the clipping by varying the input signal amplitude. Like I said, it was just a mental doodle, I have no actual plans to make anything like this, unless I get very bored one day (unlikely, but you know).

main-qimg-10af241ce6d25fb49d10c68c41553aec-pjlq


And more to the point, how do you think Teal clipping will compare to Puce clipping? 🤔

No idea - I'm not into diode clipping at all, honestly. I tried a few different LED's long ago in my little VOX solid state amp, but ended up with two different silicon diodes and a low pF value cap. Better than the original back to back red LEDs? Yes. Worth using? No, not really. Bought and fixed up an AC15, problem solved. :D
 

TheKman76

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It's kind of absurd, really. I'm not a fan of diode clipping either, but some clever bugger is gonna' take this idea and make something marketable out of it.

If you can invent a new "brown" sound I'm sure there's money in it!
 

PelliX

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It's kind of absurd, really. I'm not a fan of diode clipping either, but some clever bugger is gonna' take this idea and make something marketable out of it.

I sure hope they do. If they mention me in the process it's cool, haha.

If you can invent a new "brown" sound I'm sure there's money in it!

No doubt! Now I just have to invent brown light... and when I do; Newton, eat your heart out!
 

GustHFS

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I think there's a problem with that too. The LEDs do not emit so much brightness with voltage passing during clipping (especially on soft-clipping situations) that it is interesting or visually striking. In practice, I don't even know if it really would have any visual appeal or help in adjusting some parameter. There is the fact that the size of the LEDs also influence the behavior of the circuit. But for those who have a good background in designing circuits (not my case) it might work, or maybe it really is possible to get some new "brown sound" from another world. Who knows? Anyway, I'm finding this thread very interesting.

EDIT: Just don't let Brian Wampler or Josh Scott read this thread💡💡

Gust
 
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PelliX

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The LEDs do not emit so much brightness with voltage passing during clipping (especially on soft-clipping situations) that it is interesting or visually striking.

That would be a key concern. As it happens, the LEDs will light up just fine when clipping - that's not a problem, but there has to be signal for them to light up. Not very user friendly, I guess. Perhaps one could have a second RGB LED powered straight from the power source (battery/PSU) which represents the current setting *without* signal.
 

PelliX

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That would be a key concern. As it happens, the LEDs will light up just fine when clipping - that's not a problem, but there has to be signal for them to light up. Not very user friendly, I guess. Perhaps one could have a second RGB LED powered straight from the power source (battery/PSU) which represents the current setting *without* signal.

Dual gang pots would do the trick... or just a few transistors. Many ways to skin this cat. I tend to ignore power consumption in these type of projects as I almost always work on the basis of their being a constant supply, but when dealing with batteries, I'd have to do some calculations to keep the consumption as low as possible. Perhaps a microcontroller which takes the input from the pots via ADC's and then drives optoisolators *and* the 'indication LED' with PWM. You can run an ATtiny on half a potato...
 

TheKman76

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Don't get bogged down in the detail, man. Think 'Vision', think 'Brown'!

Power efficiency... Pfst! Genius' don't concern themselves with such things. That's for the mere Engineering plebs!
 

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