J201 vs. 2N5457... Any Difference?

[squirrels]

Hey everyone... I’ve got a question about JFETs, mainly the differences between J201s and 2N5457s. I haven’t done many JFET based builds and only had a few 2N5457s on hand for my Wizard build. I find it a bit underwhelming honestly. I’m using a 2N1304 (@100 hFe and around .08 leakage) if that helps. Would using the J201s be beneficial? I’ve read that some people favor one over the other. Any opinions/advice would be appreciated.

[Sensei Tim]

j201's typically have more gain than 2n5457.

check the data sheets!

j201:  https://www.mouser.ca/datasheet/2/308/MMBFJ201-1301461.pdf

2n5457:  https://www.mouser.com/datasheet/2/308/MMBF5457-1301410.pdf

j201's also have a much wider voltage range compared to the 2n5457.

[squirrels]

Thanks Tim.

[Sensei Tim]

also, make sure that if you're using thru hole versions of the JFETs that they are real, legit versions.  the majority of the ones you get on ebay and tayda are either fakes, out of spec, or work-a-likes.

The best way to be sure that you're getting "real" ones is thru reputable places like smallbear or mouser or digikey, or to use SMD versions with a TH adapter (I'm pretty sure this is still cheaper than buying "real" TH versions)

[squirrels]

I had a few 2N5457s from Small Bear that I used for The  Wizard. I haven’t tested them besides in the pedal which works but wasn’t what I was looking for. I was just wondering if J201s would possibly make a difference in the circuit. Generic J201 are still available from Small Bear.

[Sensei Tim]

not familiar with the wizard circuit, but were they biased properly (if they needed to be biased)?

[JSquires820]

CONTENTS DELETED

The author has deleted this message.

[Muadzin]

The problem and pain in the ass with JFET circuits is that you need to bias them. Either via trimpots and multimeters, or by selecting matching sets of transistors. Which produces better sonic results, but in which case you need a buttload of them in order to sort and find matching sets. And while ordering a bag of 100 J201's was easy and affordable when they were like $0,05 a pop, today that means dropping serious money. Let alone that there are so many fakes out there.

Mu amp pedals like the Catalinbread pedals are far more forgiving.

[squirrels]

I get that, the Citrus was the first one ( elides the Sonic Titan) that I had to bias the JFETs manually. I used my new multimeter and socketed resistors. The odd thing was that I after I had it boxed up it started to sound off. I checked the bias again and Q4 was reading at 6.9v. I give up on that one.

Back to the original question, I didn’t notice much difference between the J201s and 2N5484s in the Wizard.

[Sensei Tim]

Muadzin wrote

The problem and pain in the ass with JFET circuits is that you need to bias them. Either via trimpots and multimeters, or by selecting matching sets of transistors. Which produces better sonic results, but in which case you need a buttload of them in order to sort and find matching sets. And while ordering a bag of 100 J201's was easy and affordable when they were like $0,05 a pop, today that means dropping serious money. Let alone that there are so many fakes out there.

Mu amp pedals like the Catalinbread pedals are far more forgiving.

that's the exact reason why i dumped TH jfets and went to SMD with adapters for stripboard builds and now i just design my PCBs to use SMD jfets from the start.

I've wasted so much time (and money) as a result of fake/out of spec/workalike parts that i refuse to even look at buying those things from places other than mouser or digikey

[Travis]

Some of the more popular through hole FETs have been reissued by ON Semi. I have bought some of the 2N5457 and I got a lot of matches in a small batch. They seem very consistent.

I’m happy because I don’t know how to match the FETs using SMD parts without the annoying adapter board. It’s faster for me to work with the through hole parts. Thank you ON Semi!!!

[Sensei Tim]

Yeah I can see how matching smd fets would be a pain.... unless they all match out of the box hah.   I’ve never built anything that needed get matching.

On Sat, Feb 1, 2020 at 9:27 AM Travis [via Guitar FX Layouts] <[hidden email]> wrote:

Some of the more popular through hole FETs have been reissued by ON Semi. I have bought some of the 2N5457 and I got a lot of matches in a small batch. They seem very consistent.

I’m happy because I don’t know how to match the FETs using SMD parts without the annoying adapter board. It’s faster for me to work with the through hole parts. Thank you ON Semi!!!

---

If you reply to this email, your message will be added to the discussion below:

http://guitar-fx-layouts.42897.x6.nabble.com/J201-vs-2N5457-Any-Difference-tp48048p48151.html

To unsubscribe from J201 vs. 2N5457... Any Difference?, click here.
NAML

--

[Travis]

I’ve been curious if the SMD ones are so consistent that they just match right “out of the box”. Haven’t had the confidence to solder something together based on that premise.

You should build an 1176 clone, I think you’d like it