Author Topic: Will these diodes be ok for K.O.T build?  (Read 428 times)

Governor

Will these diodes be ok for K.O.T build?
« on: September 17, 2019, 05:04:35 AM »
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

Re: Will these diodes be ok for K.O.T build?
« Reply #1 on: September 17, 2019, 05:43:50 AM »
Can't follow your signature changes, Stephen..!!
but I like what follows:
"put the coffee down, Antonis, and nobody will get hurt."
"Arggg, Jim ...."

Governor

Re: Will these diodes be ok for K.O.T build?
« Reply #2 on: September 18, 2019, 04:13:28 PM »
ok, so theses wont be any good then?

Kevin Mitchell

Re: Will these diodes be ok for K.O.T build?
« Reply #3 on: September 18, 2019, 04:45:27 PM »
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

Governor

Re: Will these diodes be ok for K.O.T build?
« Reply #4 on: September 19, 2019, 03:37:56 AM »
Thanks, yes I did come across the pedal hacker site - are these legit authentic parts?

patrick398

Re: Will these diodes be ok for K.O.T build?
« Reply #5 on: September 19, 2019, 05:10:58 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

Re: Will these diodes be ok for K.O.T build?
« Reply #6 on: September 19, 2019, 06:18:09 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. 
« Last Edit: September 19, 2019, 08:22:53 AM by EBK »
No affiliations. If I glowingly mention specific merchants or products, it is because I like them without having to be paid to like them.

Fenton Bresler

Re: Will these diodes be ok for K.O.T build?
« Reply #7 on: September 19, 2019, 07:53:13 AM »
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

Re: Will these diodes be ok for K.O.T build?
« Reply #8 on: September 19, 2019, 09:07:18 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:
Can't follow your signature changes, Stephen..!!
but I like what follows:
"put the coffee down, Antonis, and nobody will get hurt."
"Arggg, Jim ...."

Governor

Re: Will these diodes be ok for K.O.T build?
« Reply #9 on: September 20, 2019, 06:06:59 PM »
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

Re: Will these diodes be ok for K.O.T build?
« Reply #10 on: September 21, 2019, 12:55:05 PM »
Id say, put them in and let it rip. No harm done when experimenting with clipping diodes.
"In the beginning there was nothing - which exploded" - Terry Pratchett