J201 and 2n5457 replacements

[tabbycat]

i don't think i'm a prolific enough user for the amount i consume to make a huge dent in the 3000. but if there were 30 of us who could commit to 100 each, that would work out ok. and i know there are hardcore builders here that are going to want a lot more than that each, which would reciprocally reduce the need for others to commit to so much upfront.

i know nothing of chinese soldering houses or which smd j201 are fit for that purpose, but if someone said 'would you be up for x pre-soldered boards at x cost?' i could commit to a certain amount, and adding my count to that of others they could maybe get an idea of whether this would be a viable thing. show-of-hands situation.

but i like the group buy notion. partly because it would mean i'm able to get bona fide 201 affordably (although i don't count on any meaningful savings, as my need for them is so modest). but even more as a community thing, because i think it might be a starting point for a flurry of interesting 201 related projects and experimentation.
'well now we've all got a reliable and plentiful supply of these things, what are we going to do with them...?' kind of thing.
so my interest is not only in the 201 boards themsleves but the climate of 201 related projects that might ensue as a result of having so many hit the membership's collective workbenches at the same time.

that spark in a tinderbox aspect of it amuses me.

[j-pee]

hi all,

I know this is not 2015 anymore, but 2020...
but this is a very fundamental thread, I wish everyone would read Beaker's comment, for example:

Beaker wrote

In short, there aren't any.

It may be possible to replace them with other JFETs, but only on a few circuits - most pedals that require these JFETS don't really work very well with replacements. (I think I read somewhere that J230 work in some builds that spec J201).

When you take into account the amount of fake 2N5457 and J201 transistors that you will come across - especially from Chinese ebay sellers, we are in a bit of a bind.

We have had guys on here already, having all kinds of problems with JFET builds - problems that they should not really be experiencing, or should be easy to cure. The problems result from the fact that they have bought a batch of fakes, and they don't realise it. It's only when they have swapped the fake parts for genuine ones, the problems resolve themselves.

The good news is that you can buy surface mount JFETS and tiny PCB adapter boards that you can use in their place - although they are not widely available. Hopefully someone will reply with a source for these.

I have found places to get 1000, but not 10 or 20!

also, since this is 2020 already, we shuold mention that J201 is being produced again,
see mouser.com

manufacturer is Interfet
https://mouser.com/datasheet/2/676/jfet-j201-j202-interfet.r00-1649170.pdf

another thing to mention is the 2SK170 which is also available (I didn't check mouser.com, buit at a local shop in Budapest they have it, good shop, realiable) in fact, two reliable local shops have it...

BUT, nevertheless, the SMD version + adapter buying project is absolutely the best !!! :)

[Sensei Tim]

I have gone full SMD for JFETs and haven't looked back.

I just bought 100 MMBTj201 for $20 or $22 CAD from mouser.  the interfet j201's are something like $4-5 CAD EACH on mouser.  no thanks.


For people who are interested in SMD adapter boards.

I've been thinking about ordering a few hundred and selling them in batches of 10 or 20 for a modest price.  for these smaller quantities i can post them via letter mail and avoid the outrageous shipping fees.

I've also been messing with a small 18v charge pump circuit with built in over-voltage protection.  you just supple a TH zener diode (9.1v or 12v or whatever you want the input voltage limit to be) and the charge pump and you're good to go.  the board can accommodate LT1054, 7660s and 1044 charge pumps.

Would there be any interest?

[joejoe]

so are the tayda j201s fake??

https://www.taydaelectronics.com/j201-jfet-n-channel-amplifier-transistor.html

[Pavlos]

not necessarily fake, but some people have been 'burned' in the past when buying through hole JFETs from Tayda, so could be worth going for a source that has a good reputation when it comes to the slightly less generic components (JFETs, unusual / out of production transistors and IC's)

Due to easier availability more reliable quality and reasonable cost, a lot of people on here have gone over to using SMD JFET's mounted on an adaptor board. They are quite fiddly little buggers to solder to the boards, but the big positive is that in my experience they are incredibly consistant compared to the through hole JFETs.


If you check the thread on reliable sellers you should find somewhere suitable.

Personally, for the SMD JFET's and boards, I've had good results on multiple occasions from Bitsbox (Shipping within UK is usually only about 3-4 days) http://www.bitsbox.co.uk/ and DIY Guitar Pedals (Shipping from Australia to UK has been less than 14 days and carriage charges are very reasonable) http://www.diyguitarpedals.com.au/shop/