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DIY Stompboxes => Building your own stompbox => Topic started by: haveyouseenhim on April 19, 2014, 12:09:50 AM

Title: LED clipper question.
Post by: haveyouseenhim on April 19, 2014, 12:09:50 AM
I was just wondering if instead of using two LEDs for clipping, would a single bi-color led work? What I'm referring to is the bi-colors with two leads. I have one that has a green and yellow diode with almost the same forward voltage that I figure might work.
Title: Re: LED clipper question.
Post by: PRR on April 19, 2014, 12:35:57 AM
> I have one

So put it in and tell us.
Title: Re: LED clipper question.
Post by: haveyouseenhim on April 19, 2014, 01:28:53 AM
It's on a fabbed board that isn't anywhere near done. I was just wondering.

Thanks for your help ::)
Title: LED clipper question.
Post by: pappasmurfsharem on April 19, 2014, 01:30:52 AM
Quote from: haveyouseenhim on April 19, 2014, 12:09:50 AMI was just wondering if instead of using two LEDs for clipping, would a single bi-color led work? What I'm referring to is the bi-colors with two leads. I have one that has a green and yellow diode with almost the same forward voltage that I figure might work.

It would need 4 legs wouldn't it?

Otherwise one diode will be shorted or it would be the same as two in parallel I guess
Title: Re: LED clipper question.
Post by: haveyouseenhim on April 19, 2014, 01:38:02 AM
Quote from: pappasmurfsharem on April 19, 2014, 01:30:52 AM
It would need 4 legs wouldn't it?

Otherwise one diode will be shorted or it would be the same as two in parallel I guess

It seems to be two in parallel like in a clipping section. I'm just wondering if anyone has used it before, and it if works well.
Title: LED clipper question.
Post by: pappasmurfsharem on April 19, 2014, 02:04:38 AM
Quote from: haveyouseenhim on April 19, 2014, 01:38:02 AM
Quote from: pappasmurfsharem on April 19, 2014, 01:30:52 AMIt would need 4 legs wouldn't it?

Otherwise one diode will be shorted or it would be the same as two in parallel I guess

It seems to be two in parallel like in a clipping section. I'm just wondering if anyone has used it before, and it if works well.

Yes parallel but it would only clip one half if the waveform. Since both cathod leads or anode depending on the led would be on the same side. So it would work but you'd need another diode in anti parallel( if that is the correct term) to clip the other half of the waveform

Since most of these LEDs share a common anode or cathode. Unless it has 4 lega
Title: Re: LED clipper question.
Post by: haveyouseenhim on April 19, 2014, 02:14:52 AM
They are anti parallel. If I put power to it it shows one color. When I reverse the polarity it shows the other color.
Title: Re: LED clipper question.
Post by: pappasmurfsharem on April 19, 2014, 02:18:23 AM
Quote from: haveyouseenhim on April 19, 2014, 02:14:52 AM
They are anti parallel. If I put power to it it shows one color. When I reverse the polarity it shows the other color.

Ooo it's not a common cathode/anode type then fancy.

Throw it to ground after a booster and see if it clips both sides. :)
Title: Re: LED clipper question.
Post by: samhay on April 19, 2014, 02:43:44 PM
The bicolour LEDs with 2 legs work great anywhere you would use antiparallel clipping diodes. They are often my preference if I want asymmetric clipping LEDS.

Edit - yes, they clip both sides.
Title: Re: LED clipper question.
Post by: zintolo on April 19, 2014, 03:37:08 PM
Done, they work perfectly and of course they clip both sides, asymmetricaly.
Title: Re: LED clipper question.
Post by: chi_boy on April 19, 2014, 05:05:03 PM
Sounds like a neat trick; I haven't run into those yet.  Where did you find them?  A link perhaps?
Title: Re: LED clipper question.
Post by: haveyouseenhim on April 19, 2014, 06:06:02 PM
I found a few on a gutted mixer board. I figured they might work. I just don't have anything built at the moment to test it on.
Title: Re: LED clipper question.
Post by: boogietone on April 19, 2014, 10:17:42 PM
Quote from: pappasmurfsharem on April 19, 2014, 02:18:23 AM
Quote from: haveyouseenhim on April 19, 2014, 02:14:52 AM
They are anti parallel. If I put power to it it shows one color. When I reverse the polarity it shows the other color.

Ooo it's not a common cathode/anode type then fancy.

Throw it to ground after a booster and see if it clips both sides. :)

I think it would be this. Anode - cathode for one color. Cathode - anode for the other.
Title: Re: LED clipper question.
Post by: Jdansti on April 20, 2014, 01:17:06 AM
Quote from: haveyouseenhim on April 19, 2014, 06:06:02 PM
I found a few on a gutted mixer board. I figured they might work. I just don't have anything built at the moment to test it on.

I think you made a Valvecaster. Tie the bi-LED between the Valvecaster's output and ground. You could do this from the output jack and not have to open up the enclosure. Turn the Valvecaster's gain down so you only hear clipping from the diode. You could do this with any high gain pedal. I've got a passive clipping box with several diode types that does the same thing.