PF5102; need a sub. Here's what I have...

DAJE

DAJE

Well-known member
SMD MMBF5457s which I know to be good, already mounted on adaptor boards
SMD J201s which I suspect to be bad, also mounted on adaptors
J107s known good
2N5457s out of spec, bad

I have some good testing devices but really don't know what to look for; don't ask me to do any maths beyond the very basic.

I'm putting in a Tayda order soon but there's not much in stock for n-channel JFETs.

They have:
2N5458
J112
J111
MMBFJ202

I might be able to locate something locally (Australia) if anyone has another suggestion.

EDIT: For a Woodpecker Tremolo, if that matters.
 
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temol said:

Substituting the 2N5457 – Stompville

stompville.co.uk stompville.co.uk
especially the table with transistors specs (Vgs(off) and Idss)
Click to expand...
Interesting, but all of these discussions assume I know what a JFET does, and thus understand whether the numbers need to match or not in any particular circuit. I know nothing. I can solder OK, I understand some rock bottom basics, but the rest of it is gibberish to me.
 
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DAJE said:
SMD MMBF5457s which I know to be good, already mounted on adaptor boards
SMD J201s which I suspect to be bad, also mounted on adaptors
J107s known good
2N5457s out of spec, bad

I have some good testing devices but really don't know what to look for; don't ask me to do any maths beyond the very basic.

I'm putting in a Tayda order soon but there's not much in stock for n-channel JFETs.

They have:
2N5458
J112
J111
MMBFJ202

I might be able to locate something locally (Australia) if anyone has another suggestion.

EDIT: For a Woodpecker Tremolo, if that matters.
Click to expand...
You will not find them cheaper locally, being an obsolete part now.
They were 30c each 3 years ago from here :

PF5102 N-JFET TRANSISTOR [SEMN0035] - $4.20 : Pedal Parts Australia, DIY Guitar & Effect Pedal Parts

Pedal Parts Australia PF5102 N-JFET TRANSISTOR [SEMN0035] - DETAILS: PF5102 N-JFET
www.pedalpartsaustralia.com www.pedalpartsaustralia.com
 
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And sorry if I seem a bit clueless here, I'm running up against the limits of my ability in this area. There are other things I can do well.

I'll try measuring what I have and see if I can make sense of it.
 
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After reading through a few other's experiences, I'd try (in order) 5457, J112, 201. Mind the pinouts. Hope you land one!
 
I just spent a surprisingly interesting hour testing my various JFETs and making a text file of the results. Including some that I know work properly that I de-socketed from pedals. Looks like my SMD J201s may not be bad after all, the numbers aren't all that far from my known good ones.

Going to look through my saved build docs to remind myself what other pedals have JFETs I can test.
 
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