Will these diodes be ok for K.O.T build?

Started by Governor, September 17, 2019, 05:04:35 AM

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Governor

Hi, I know what your thinking - another "what diode to substitute MA856 for KOT build?", but I have found a stash of old (never been used probably 20+ years old) diodes (I work in the electrical industry with an electronics workshop).  I've found 2 different ones, both have a FV of 0.72V (measured with Fluke MM).  I was going to just going to use IN4148 as I cant get hold of any MA856, however I managed to source a couple of 1S1588.

One is grey and has a Motorola 'M' logo on it along with 1N4752A
The other one though I cant make out the marking, its clear and physically looks like a 1N4818.

Will these be better than 1N4148's?

antonis

"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

Governor


Kevin Mitchell

Nope.

Oh look what a quick google search shows as the 1st result;
https://www.pedalhackerelectronics.com/Original-Panasonic-MA856-Diode-p/ma856.htm

You could probably get by using a 1N4148, 1N914 or even a rectifier diode (1N400X series).

-KM
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Governor

Thanks, yes I did come across the pedal hacker site - are these legit authentic parts?

patrick398

Quote from: Governor on September 19, 2019, 03:37:56 AM
Thanks, yes I did come across the pedal hacker site - are these legit authentic parts?

I have a KOT i bought used years ago and i'm pretty sure it just uses 1N4148. Always sounded pretty good to my ears. Try some LEDs too, i'm a big fan of the way they clip

EBK

#6
Quote from: antonis on September 17, 2019, 05:43:50 AM
BTW, 1N4752A is 33V/1W Zener diode..
But, what's the forward voltage?  There is nothing inherently wrong with using a zener diode as a forward-biased clipping diode (unless the forward voltage is too high, I suppose).

Edit:  I see above that the forward voltage was measured at 0.72V. 
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Fenton Bresler

Yeah I don't see what's wrong with using zeners as clipping diodes. Isn't the Vf of a zener or avalanche diode roughly a silicon diode drop i.e ~0.65V?

antonis

Quote from: EBK on September 19, 2019, 06:18:09 AM
There is nothing inherently wrong with using a zener diode as a forward-biased clipping diode (unless the forward voltage is too high, I suppose).
Indeed, except for the case of using a single Zener diode for asymmetrical clipping.. :icon_wink:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

Governor

The other ones I found that looks similar to a 1N4148 is a 79C7V5 (I found a couple more I could make out the ID), these have a FV average of 0.73v.  Would these be ok to use?  0.73 is fairly close to the MA856 fv 0.75.

KarenColumbo

I'd say, put them in and let it rip. No harm done when experimenting with clipping diodes.
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