The don't fake JFETs now.......do they?

[GGBB]

if builders less prolific than you convince themselves fakes are a significant concern, they might waste time and money shopping for more parts instead of just building more things and learning a little theory and making less cold joints and shorts and broken wires, etc.

On the other hand, if someone less technically inclined about such things decides to build a Fetzer and gets all their parts including the FETs online from Discount Pedal Parts Emporium because they have everything and they are cheap, and then find their pedal doesn't work properly or sound right and they can't figure out why, and it turns out to be, after a big long debugging thread here, out-of-spec FETs, which when replaced by ones from Small Bear, work properly and sound great, isn't that just as non-productive?  (Talk about your run-on sentences.)

I agree about just building, learning, and honing skill, but bad parts can be a real frustration and discouragement as well as a huge waste of time.  I think once you go down that road you forget about iffy discount suppliers, so why bother in the first place?

[solderburn]

I meant if they were out of speck, Not if they were actually functioning or not. I do prefer to place as few orders as possible, and use a extremely low budget so tayda works good for me. I am going to get a Multimeter and buy some parts from Small Bear and Aron soon and will get some J201 for comparison to see if there out of speck.

[pickdropper]

Has anyone ever bought any transistors from Tayda? are they real?

Of course they're real. No offense, but this thread is crazy. People's pedals don't work because they make mistakes, not because of fakes. Swim through the forum, you'll find a million threads that start out with someone thinking they have fake whatever because they bought cheapo parts. Inevitably, the issue is incorrect orientation, cold solder joints, shorts somewhere, messy vero, etc. Yes, there are some fakes of really expensive rare items, yes some cheapies are out-of-spec, but no one is wasting their time trying to con pedal builders into dropping 3 dollars on fake FETs, get real.

Well, by "fake" most of us aren't talking about it not really being a transistor, or causing a build to fail, but rather that what's printed on the case isn't what it specs as. The "fakes" are a pain for two reasons: (1) Most of them are lower gain than the ones we want (J201s or 2N5457s), and (2) FETs are inconsistent enough without adding out-of-spec to the mix.

The gain issue is particularly relevant when making overdrives or FETzer valve stuff, because there's only so much voltage gain you can expect before you have to use a different bias point and mess up the sound qualities of the design.

If I buy 10 JFETs from Smallbear or the DIYSB forum, I can be reasonably sure I don't have to test them to find out if I need a different trimpot value or redo my biasing network so that something that's normally near 5-6V is suddenly 2-3V like they're a completely different transistor that's not even remotely comparable to the J201. When I was getting them from Tayda, I'd have to resort them when they came in the mail, and they're not any cheaper.

I've gotten Jfets from Tayda that had a VGS that was out of spec.  So they were most likely either: a.) relabeled JFets of another type or b.) way out of spec real J201's.  Either way, they weren't what I wanted.

At one point, I was researching a group buy of J201s and 2N5457s for the DIY community.  I deal with China as part of my day job, so I asked one of the folks I know in China to get some samples of J201 and 2n5457 for me from a reputable seller (ie: a reputable place with a storefront, not a garage/warehouse eBay type seller).  I bought 100 samples of each type with plans to buy thousands more if legit.

To cut to the chase, all were fake.  In fact, one of them was a p-channel jFET, not an n-channel jFet so they didn't even relabel the correct type.  :-)

I have some known legit ones here for comparison.  And everything I've gotten from Steve at Small Bear has been legit.  I wish I would've stocked up at Mouser before they went EOL.  Luckily, I happen to like working with SMT bits.

[hymenoptera]

Just reviving this old thread to share my experiences with buying fake JFETs.

I just received 10x fake 2n5457 from polida this week. When tested on the Peak Atlas DCA75 Pro they all show the correct range of pinch-off voltage, Idss saturation current, etc, BUT the pinout is wrong.

2n5457 should have the gate on the end. These all have their gate in the middle.

I'm eventually going to insulate and twist the leads on one and try it in something to see if they're suitable work-alikes for something, but for now I'm pretty disappointed in what I got. Now I'm looking at my desk (covered in $50 worth of various ICs from the same order which almost all have suspiciously similar looking laser engraving...) and wondering what else I bought that isn't quite as described.

Anybody out there have any idea what JFET has similar specs to a 2n5457, but with the gate in the middle??

[darron]

that's a turd. luckily you can normally tell (after learning your lesson) from the picture. fairchild FETs have a letter on the back. if i were buying a lot i'd normally ask "does it match the picture" and if i don't get a response back then let it go.

everyone said "you're making a fuss over nothing". and now, gone. i notice even small bear electronics can't keep a stock of fairchild J201 anymore. luckily i bought a stack of real 2n5457 for the future cheap.

the SMD versions of 2n5457 and j201 use gate in the middle.

sorry i don't know what they might have been originally.

[anotherjim]

Could be BF series with gate in middle. Don't know why anyone should fake them as something else. If they were cheap and work and you've been smart enough to catch the pin-out change, I'd count it as a win.
I know a main UK supplier that has Fairchild TO-92 2n5457 in stock. 1-24 price of £1.04 each inc tax (that would be $1.63USD). It's the only Jfet they have of any kind.

[duck_arse]

k30A has middle gate, near specs. one of the BF family is also middle gate, but the bf245's are end-gate, but opposite to 2n5457.

[pickdropper]

Small Bear still has some stock of real FETs.

Also, Central Semiconductor has started making TO-92 2n5457s again.  They are pricey, but Mouser does a few in stock:

http://www.mouser.com/Search/Refine.aspx?Keyword=2n5457

[LightSoundGeometry]

what am I looking for on the data sheet? my measuring gadget shows - I. which I am guessing is current? and a miliamps I think..its a bunch of symbols  - .51 - .74  they read

then a Vgs = 500-525

not sure how to read those data sheets.

[hymenoptera]

Hairball Audio (Mike Mabe in Seattle who does the 1176 FET compressor kits; wicked killer products btw) sells original Fairchild 2n5457's for what comes out to 0.50 each before shipping, so I just bought 10 pairs a few minutes ago. With shipping they come out close to $1 each, but it's still better price than I'm seeing in most places.

They are the leftovers from after sorting through hundreds (or thousands?) of FETs and matching them for their Vgs curve for use in his 1176 compressor kits. Each unit has 2 FETs, one which acts as a variable resistor to ground in a feedback configuration; the more signal going in the more the compressor opens up and dumps signal to ground, while the other FET is used in the VU meter, so each must be matched relatively close for the meter to track gain reduction with any accuracy. So I can only imagine that he ends up with piles of FETs that don't meet his specs.

I think I'll also buy some from Smallbear too, then I'll have enough to last me for awhile.

At least I'll know these orders will all be authentic 

[J0K3RX]

Posted this in another forum bout a year ago in response to the never ending debate in regards to suspected counterfeit electronic components...

To the nay-sayers - disbelievers
Look up/google - Detection of counterfeit electronic components through ambient mass spectrometry and chemometrics

Would Mouser, Digi-Key and other large distributors employ large "Anti-Counterfeit Parts Risk Mitigation" task forces if this were complete non sense?
http://www.mouser.com/anticounterfeitparts/
http://www.mouser.com/quality/

So, the next time you guys load your baskets up at Tayda just keep in mind... They are not a "AS9100C Registered Distributor" and they have no certifications what so ever the last time I looked but, they do however have a great satisfaction guarantee and return policy and from what I have seen they make good on it almost 100% of the time. I personally do not want to call up or email a supplier every time and ask for a refund or in store credit... I would prefer to get what I ordered the 1st time!

These "Hobbyist Suppliers" are just that and nothing more. I doubt they supply to the military, automotive, aviation, medical or any others that require industry wide certification of their components. Handling, packaging and delivery of components also falls under the guidelines of these certifications and must be taken into consideration as well.

If the supplier/s that you are buying from is not a "AS9100C Registered Distributor" with the following certifications then good luck to you and your pedals or whatever you are building...
AS9100C and ISO9001:2008 and ANSI/ESD S20.20-2007 certifications.

If they are registered and certified they will proudly and publicly display their certifications!
http://www.mouser.com/as9100C/



This is a HUGE deal for medical, aviation, military and countless other industries where lives and or money hang in the balance. They can not afford to have failures due to counterfeit, failing or out of spec/reject components and go to great measures to make sure this does not happen. This is nothing new and has been in place for years...

Also, keep in mind that this is not just something that is happening with a few parts like JFETs and PT2399's... This is industry wide and they do it with everything they possibly can! It is a multi-billion dollar maybe trillion dollar a year market and they can re-mark these components and ship them faster than you can say stompbox!

[pickdropper]

These "Hobbyist Suppliers" are just that and nothing more. I doubt they supply to the military, automotive, aviation, medical or any others that require industry wide certification of their components. Handling, packaging and delivery of components also falls under the guidelines of these certifications and must be taken into consideration as well.

There is zero chance any of those industries would buy something from Tayda, for many reasons, quality being the primary one.  On a side note, there were some rumors of military contractors buying parts from Radio Shack back in the 80's because of convenience or scheduling issues.  I guess they don't have to worry about that anymore.

[Daemons]

I just received 10x fake 2n5457 from polida this week. When tested on the Peak Atlas DCA75 Pro they all show the correct range of pinch-off voltage, Idss saturation current, etc, BUT the pinout is wrong.

I bought from the same seller 08/31/15. I'm currently arguing with them to get my money back.
The ones I got look sanded, the leads are corroded, and have no markings in the back. Oh, and wrong pinout!
It pisses me off because I've bought from polida2008 in the past and had good quality. I really thought they were above such crap, but I see they couldn't resist the higher profits, just like other chinese sellers.

2n5457 should have the gate on the end. These all have their gate in the middle.

Anybody out there have any idea what JFET has similar specs to a 2n5457, but with the gate in the middle??

Pinout is same as 2N3819. I need to do the VP and Idss test posted on this thread to see what I have. I suspect they're 2N3819s. What were your values? I'll see if it matches mine.

I bought 2N5458s from Tayda, and they're correct pinout, look the part, and work great. Tayda has been out of 5457s for a long time now, so maybe they're having trouble finding a legit supply of them.
Tayda is in Thailand, not China.. not sure if that matters, but I haven't had problems with them, yet <fingers crossed>.

I'm just gonna order MMBF5457s from digikey. It's $5.47CDN for 10.. not cheap but at least I know they're real. Well.. not cheap compared to fake chinese parts on eBay.. so it's actually a very good price all things considered.

Daemons

[LightSoundGeometry]

I buy everything from tayda except my active parts come from small bear or this other dude on ebay, who I tracked to his facebook page and looked at all his projects. He is legit. his work is clean and beautiful and is money back guarantee like small bear if things dont measure out right. 

My new peak atlas should arrive in mail friday!!  I want to get me a bench power supply, a function ac generator and oscilloscope like we have in lab. I know they throw stuff out sometimes when they upgrade, I might have to dumpster dive for an item lol

maybe the forum has some outdated, old testors they no longer use that might be perfect for a first year EE student on the cheap 

polida ripped me off as well..I got some Fets and IC that would not work despite twisting legs.  I know RG probably will hate me but I ordered six of the juried engineering IC chips just to see what they were all about and run some tests with the other ICS I have. I only paid a dollar piece which is double the bear but i couldnt resist doing the a/b side by side and in same circuit tests

[Daemons]

Hello,

A quick update... I got my money back from polida for my Fake 2N5457s. I had to threaten them with neg feedback and opening a case with eBay for counterfeit item to get my refund, but it worked.
They still kept delaying it, until I sent them a note last night saying I guess they do want me to open a case and leave neg feedback, since I still hadn't received my refund yet. That seemed to get them to move.

It's very unpleasant to have to deal with miscreants like these shady sellers from China. I think eBay needs to make it easier for victims to report, and claim counterfeit items. As it is now, if you open a case the seller can demand that you ship the item back at your cost in order to get your money back, for an item that is counterfeit.. how is that right? They know you're on the losing end.. so they try to delay everything past your ability of leaving feedback, and then they know you have no power over them and they get away with it.

Anyways, I've come to the conclusion that there are no more 2N5457 being manufactured in TO-92 case, only SMT.
2n5458 seems to be the last ones, and I'm guessing it's only until the current stock is depleted. Better stock up on SMD adapter boards, as that's where we're heading folks..

D.

[jubal81]

I have embraced the new SMD overlords. All our favorite JFETs are available and even some great ones that never appeared in TO-92. The SMD versions have much more consistent specs, too.

In fact, just ordered this:



For use with this:

[hymenoptera]

jubal81, what is it??

[garcho]

the SMD to DIP boards are cheap and easy

[pickdropper]

I have embraced the new SMD overlords. All our favorite JFETs are available and even some great ones that never appeared in TO-92. The SMD versions have much more consistent specs, too.

In fact, just ordered this:



For use with this:

Those are useful.  I use one of those for testing and matching FETs.



You do have to be careful when loading it.  It's fairly easy to get the pins misaligned.

[jubal81]

I shared some SMD JFET adapter boards on OSH park anyone can order. There are two versions. One for DGS, and the other for GSD. Each has SMD pads on either side, meaning you can use any SMD JFET with either one, depending on what you need for the specific effect. GSD is the more common for us (5457, 201).

Here's a link to my shared projects:
https://oshpark.com/profiles/Jubal81