# Diffuse or Crystal Clear LEDs in Distortion Pedals?



## Caldo71 (Jan 1, 2021)

Preemptively let me say I think I already know the answer, because every diode-based distortion pedal I own, or build photo I see here/elsewhere uses the DIFFUSE ones.

...BUT...

As I understand it, the diffuse LEDs are all just white LEDs with colored plastic housings. So if that’s the case, why would you see pedals like the Suhr Riot use a MIX of diffuse red and blue LEDs?

Meaning, you’d mix colors to get different VALUES out of the LEDs thus somehow affecting the pedal’s TONE OR GAIN I assume, right? Yet it the diffuse ones are all just WHITE LEDs with colored shells, then the diffuse “red” and “blue” LEDs should have the SAME value, yes?

Am I making any sense here?


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## zgrav (Jan 1, 2021)

see if *this* helps answer your question.


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## BurntFingers (Jan 1, 2021)

Diffused is just using a scuffed housing to make the light less direct, it doesn't change the operation of the actual diode. 

I use 3mm red LEDs for the most part, sometimes in parallel with a 3mm green for some asymmetrical action.


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## Caldo71 (Jan 1, 2021)

zgrav said:


> see if *this* helps answer your question.


it’s a cool chart and WOULD answer the question if the type mentioned in the chart (the “crystal clear” LEDs) were the type that I ever saw people using in their builds.

But they don’t seem to be using that type in any build I’ve seen photographed or in my collection: they’re using a red/blue (or whatever) mix of what are in truth just white LEDs with the same values/semiconductor materials, and they only “present” as different colors due to colored plastic housings.

So if people are using LEDs with mixed colors to do “assymetrical clipping” when in fact all of ‘em are the same whiteys under the hood, just with fake colored housing, aren’t they just fantasizing?


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## Caldo71 (Jan 1, 2021)

BurntFingers said:


> Diffused is just using a scuffed housing to make the light less direct, it doesn't change the operation of the actual diode.
> 
> I use 3mm red LEDs for the most part, sometimes in parallel with a 3mm green for some asymmetrical action.


Not sure that’s always true. Look at any build pic in this forum and you’ll see a housing that isn’t just frosted clear plastic...they’re made of translucent frosted plastic that is clearly pre-tinted in red or blue.

I explained myself a little more maybe in my reply to Zgrav above?


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## Danbieranowski (Jan 1, 2021)

Caldo71 said:


> Preemptively let me say I think I already know the answer, because every diode-based distortion pedal I own, or build photo I see here/elsewhere uses the DIFFUSE ones.
> 
> ...BUT...
> 
> ...


I’ve never seen an instance where diffused LEDs gave me the same clipping sound as if they were all the same on the inside. You can easily test this. Just socket the diodes and test swapping some out. You can also test this more scientifically by measuring the LED’s forward voltage.
This link ( https://www.guitarpedalx.com/news/news/a-brief-hobbyist-primer-on-clipping-diodes ) has the following good info:
LED Diodes​Typical Forward Voltage - 1.2 > 4.0Vf

Obviously the ubiquitous 2 Red LEDs is well known here - being around 1.7Vf - but LEDs can range to at least twice that across the spectrum. Not all bulbs have tonally unique Vf signatures - and there are many variations within Hue and type which yield significant difference. 

Infra Red (1.2Vf)
Red (1.7Vf) - P.h.A., Red Mist, Rat
Orange (2.0Vf)
Yellow (2.1Vf)
Green (2.2Vf)
Blue (3.2Vf)
White (3.3Vf)
Pink (3.3Vf)
Purple (3.3Vf)
Aqua (3.4Vf)
Ultra Violet (3.8Vf)


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## Nostradoomus (Jan 1, 2021)

Not 100% sure what you’re after, but for fun I just measured a water clear green LED and a diffused green LED (5mm each )and they both measured the same in regards to forward voltage at 1.85v. The white waterclear gives a reading of 2.5v. Orange diffused is 1.9v red is 1.7 etc.


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## BurntFingers (Jan 1, 2021)

Nostradoomus said:


> Not 100% sure what you’re after, but for fun I just measured a water clear green LED and a diffused green LED (5mm each )and they both measured the same in regards to forward voltage at 1.85v. The white waterclear gives a reading of 2.5v. Orange diffused is 1.9v red is 1.7 etc.


This reflects my findings also.


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## Danbieranowski (Jan 1, 2021)

You can also go to 2:20 on this video and see forward voltage measurements at different levels for different colored diffused LEDs. 1.8 for red. 2.6 for blue.


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## Caldo71 (Jan 1, 2021)

Cool, cool  thanks guys. Damn interesting stuff for a newb.


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