at the risk of beating a dead horse...
I'm creating some BOMs for a few projects that i want to do. all of them use the J201, but this JFET is listed as obsolete by mouser and digikey and there are no suitable replacements suggested.
What have you guys used to replace the J201 that is readily available? I saw that the 2n5457 was suggested, but again it is listed as obsolete or "not available" by mouser.
Thanks
check your pm
Tayda or there are still a few sellers on eBay. You may want to stock up a few extra while you can
Tayda as the J201 and shipping will cost you next to nothing.
They also have the 2N5457.
I also assume our other beloved venders also have them.
NTE 458 is what is crossed at NTE's site. I've used them in place of the J201 with success.
The diystompboxes.com store still has them. They will be there unless you need a ton of them.
See....no need to worry. All is well in DIYStompbox land. ;D
Is there a surface mount equivalent of the J201 and the other discontinued through hole jfets?
Oh jeeze...so now what? In a couple of years these J201 trannies will be up there with other expensive Germaniums selling for $20+ a piece? As the J201s become scarce, I'm sure someone will find some mojo with these transistors :)
Quote from: fuzzymuff on February 25, 2013, 03:58:47 PM
Oh jeeze...so now what? In a couple of years these J201 trannies will be up there with other expensive Germaniums selling for $20+ a piece?
remember, many ge's are 40+ years old
I recall that Steve from Smallbear said he stocked up on them for years to come. However, I don't see him offering them at the moment.
You can still get J201's from mouser... SOT-23
MMBFJ201 - It's inevitable, you must conform or be assimilated :icon_twisted:
Then you can use this so you don't have to redesign your boards... Procrastinate I always say!!
http://dl.dropbox.com/u/11178619/MMBF-J201%20to%20TO-92.pdf
Use the really thin PCB and you can cut it with scissors or you can use one of those scary paper cutters :icon_twisted:
Quote from: petey twofinger on February 25, 2013, 12:45:29 PM
check your pm
Hey petey twofinger, it's not nice to tell secrets... You got a secret stash supplier we aught to know about? :-X
Quote from: J0K3RX on February 25, 2013, 06:23:30 PM
MMBFJ201 - It's inevitable, you must conform or be assimilated
Resistance is futile!!!
(http://i1160.photobucket.com/albums/q485/jdansti/9290442D-0211-49ED-AEFF-9422EE496FC7-3774-0000057FB49568D7.jpg)
well it was just that i know a place that has these , they conveniently had everything i needed for a few builds , my last order which was 97 dollars worth of crap , but i digress .
i just wasnt sure about promoting this other place here , for some reason i thought about it and it seemed like a better idea to pm the info .
i was really just trying to help where i could , trying to boost my "karma" , something i have been trying out for a lil while here :)
as too my secret stash , man those days are long gone ... :(
Tayda still has them for .20 cent a piece
I got to liking the 2n5257 anyway.
The NTE is ''hotter than ='', and 'could' be described as.. 'hard edge sounding' [even though transistors make no sound].
I apologize for forgetting to restore the line items for those devices; it's done now.
I had addressed this issue in a post maybe a year ago before Fairchild actually lowered the boom. I invested a godawful amount of money last year in numerous TO-92 parts, so as to be able to serve our market comfortably for some years. Also, I investigated the possibility of getting a foundry to take SMD JFETs and bond to headers. It can be done, though I have not had to go that route because I picked up enough parts between Fairchild's "Last Buy" and broker stock.
Take a deep breath, and know that SBE will be able to keep feeding your habit...
Regards
SD
Very cool Steve, that's sorted then. Great price point too.
Quote from: Jdansti on February 25, 2013, 10:05:17 PM
Quote from: J0K3RX on February 25, 2013, 06:23:30 PM
MMBFJ201 - It's inevitable, you must conform or be assimilated
Resistance is futile!!!
(http://i1160.photobucket.com/albums/q485/jdansti/9290442D-0211-49ED-AEFF-9422EE496FC7-3774-0000057FB49568D7.jpg)
R = U/I :D
can seven of nine do my assimilation? I don't even much like j201's.
anyone else ever used j210'S?
Quote from: Seljer on February 27, 2013, 03:43:11 AM
Quote from: Jdansti on February 25, 2013, 10:05:17 PM
Quote from: J0K3RX on February 25, 2013, 06:23:30 PM
MMBFJ201 - It's inevitable, you must conform or be assimilated
Resistance is futile!!!
R = U/I :D
+1 ;D
Somehow, capacitance is futile just didn't sound right. ;)
Quote from: duck_arse on February 27, 2013, 10:01:09 AM
can seven of nine do my assimilation?
It was tempting to post a seven of nine!!! :icon_twisted:
BTW-Sorry-haven't used the J210, but have used the J112. I'm no sure how well a J112 would work in a circuit designed for J201.
newb here, late to the party.
I want to build the ROG Supreaux. Can I use...
MMBFJ201 instead of the J201?
and
MMBF5457 instead of the 2N5457?
here's a 2N5457 link: http://physics.gac.edu/~huber/classes/phy270/SpecSheets/2N5457.pdf
thanks,
joejoe
Quote from: joejoe226 on January 10, 2014, 11:53:56 AM
newb here, late to the party.
I want to build the ROG Supreaux. Can I use...
MMBFJ201 instead of the J201?
and
MMBF5457 instead of the 2N5457?
here's a 2N5457 link: http://physics.gac.edu/~huber/classes/phy270/SpecSheets/2N5457.pdf
thanks,
joejoe
Yes, therethe same just in an SMD package.
Quote from: Ice-9 on January 10, 2014, 12:15:41 PM
Quote from: joejoe226 on January 10, 2014, 11:53:56 AM
newb here, late to the party.
I want to build the ROG Supreaux. Can I use...
MMBFJ201 instead of the J201?
and
MMBF5457 instead of the 2N5457?
here's a 2N5457 link: http://physics.gac.edu/~huber/classes/phy270/SpecSheets/2N5457.pdf
thanks,
joejoe
Yes, they're the same just in an SMD package.
So no, you can't use them instead of the other in the sense you can't drop them in. You will need to either build a small adapter board that takes the SMD to a through-hole, or create a new PCB.
Quote from: joejoe226 on January 10, 2014, 11:53:56 AM
I want to build the ROG Supreaux.
Common TO-92 JFets can be found here at reasonable prices:
http://www.smallbearelec.com/servlet/Categories?category=Transistors%2C+FETs+%26+MOSFETs
and I bought all of them from well-known distributors before Fairchild pulled the plug.
Hello ;)
A small list of replacements for the J201 in TO92 case:
J201- 2N5484, 2N5457, 2N5485, NTE458, BF245A, MPF102, 2sk117, 2SK170
Please double check with the datasheets to confirm the pinout and build a JFET MAtcher this will be a great tool with JFETS.
All of these possible replcements have a Vpo ( pichoff voltage) that allows them to be used for guitar effects, and maximum Vds that allow them to be used with 9VDC bateries.
Obviously the gain can be different , from transistor model to another, even from J201 to J201, as we all know JFETs in general suffer from lack of fabrication consistency,and thats one of the reasons companies stop producing them. I recomend using a multi-turn varianble resistor in the drain, and bias the JFET to the loudest or prefered point. Also some times the source to ground resistor will need to the exchanged to have more gain and match the J201.
Also its possible to choose th SMD version of the J201(MMBFJ201), but it will require redesigning the PCB. Its possible to simply etch a small adapter that will allow using it on a thru hole board. This solution is also good for adapting JFETs with different pin outs than the J201 to the PCB that will use J201s.
Pozdrawiam
M.
Quote from: Ice-9 on January 10, 2014, 12:15:41 PM
Yes, therethe same just in an SMD package.
Which are not that scary to solder as you think! :) You just need to add some tweezers and flux to your toolkit
At this scale you heavily rely on the surface tension to get the solder to run to where you want it so with "larger" components like transistors its not as precise work as it appears to be
Ice9, Mth5044, SmallBear, M23Bomber, Seljer
Thanks for the info. I'm not using a pre-made PCB, so I'll be ok with the SMD version. I was bummed my local shop didn't have them, then checked online and found out the TO-92 versions weren't being made anymore.
Might have to go back and see if they have a relacement M23Bomber mentioned.
joejoe
Quote from: joejoe226 on January 10, 2014, 08:11:35 PM
Ice9, Mth5044, SmallBear, M23Bomber, Seljer
Thanks for the info. I'm not using a pre-made PCB, so I'll be ok with the SMD version. I was bummed my local shop didn't have them, then checked online and found out the TO-92 versions weren't being made anymore.
Might have to go back and see if they have a relacement M23Bomber mentioned.
joejoe
Joejoe, How many j201's do you need, if you are in the UK I can pass a couple on to you, I still have a big bag full of them that I bought some time ago. Also 2N5457 I have.
JoeJoe pleasure to help, :) May I inquire you, what are you building?
But again remind you thatsome these replacements have diferent pin outs.
I also add that you will need to recalculate the source resistors to obtain the same gain. ;) I recomend reading a few tutorials about
A nice thing about knowing all the replcement for the J201 N-JFET, is, we can use recombine them and obtain different sounding stompbox.
I built a Dr Boogie , and i swaped arround several transistors (J201 (WERE MATCHED), MPF102 and 2SK117), swapped the source resistor,and I got a "better tone" out of it and with less noise but the same gain.
Quote from: Ice-9 on January 11, 2014, 08:31:29 AM
Joejoe, How many j201's do you need, if you are in the UK I can pass a couple on to you, I still have a big bag full of them that I bought some time ago. Also 2N5457 I have.
A true gentleman and a scholar!
I had seen a mention here somewhere that some of the currently available j201s (specifically from Tayda) are either counterfeit or just plain low gain. How much of a concern is this? I have only have maybe 1 dozen "vintage" j201s. Are the j201s I might get now anemic?
Possibly. The safest thing would be to buy JFETs from a known good supplier such as Small Bear.
The last batch of J201s I got from Tayda were all good, and actually every batch I've gotten from them so far. They list the brand as being National but when I get them they're labeled Fairchild. All test good and I sort them for Idss within a certain range so that I can keep drain/source resistors the same for certain circuits I use them for. Out of 45 I bought from my last batch, only 5 fell outside of the preferred range.
There is a thread from a year or so ago that someone got J201's from them that were out of spec and probably were less desirable fets relabeled as J201. Looks like they've got a better supplier now.
But ultimately, if you want to be sure you're getting something authentic, go with Small Bear.