J201's, fairchild, others, fakes etc....

[idgit]

so, seeing that I am new to all of this business, building pedals and all, I was wondering if anyone can explain the J201 thing to me..

I have  a number of builds that I am either doing or will hopefully do in the near future that require this Jfet.

I see that the Fairchild (preferred?) are no longer available but that there are a few other ones available, like the ones at Mammoth.

is there something I should be wary of?  I've read lots of things about fakes, what the hell is that? why would anyone fake a $0.40 piece?

is it something where the other rands will not stand up to the Fairchilds or is it ok to but whatever>

Confused

[GrindCustoms]

The J201 that you can source from Mammoth or Tayda are good to go.

If you plan on building an effect i.e. an OD with fixed Bias resistor for wich you have to pick through couple JFET to have the correct voltage at the Drain, my advice would be to buy 2-3x more than what you really need.

I don't see them as «fake», to me it's just the quality control that is different....a bit less consistency through out manufacturing.

Or another option wich is what i do, i buy them in lots on Ebay.

[culturejam]

Fairchild used to be the cheap brand. 

[midwayfair]

why would anyone fake a $0.40 piece?

Because they can manufacture them for a penny.

Okay, it's not so much that they're setting out to fake a 40c transistor. They're making JFETs and being less discriminating about whether the parts are in spec. If you read up on how JFETs are manufactured, it's an incredibly inexact process. Basically, you make a million FETs -- and then sort them afterward based on some number of different qualities. as you can imagine, that's where the real cost comes in (and why JFETs are more expensive than many other types of transistors in general, ignoring the rarity). This is also why FETs are so often treated like delicate snowflakes when you put them in a circuit, with a trimpot to dial them in.

I say this every time the fake issue comes up: Depending on the circuit you can probably get away with something out of spec. If it's a source-follower buffer, use any FET you can get your hands on; it won't matter. That's the most common usage, too, so How Lucky. If it's a generic gain stage that isn't driving something else to distort, you can, again, generally use almost anything. If it's a matching situation for a phaser or something, there are still many different part numbers you can use. If it's an overdrive, it may be harder to find a substitute, but a J201 isn't even the highest output JFET out there to begin with.

[pickdropper]

I generally agree with Jon on this one, although it depends on how far off they are.

Recently, I got some fakes from China and I don't believe they are even N-channel FETs.

[GermanCdn]

I've had similar success to Rej with the ebay multipacs, bought a pack of 40, matched them using George's matching rig, and all but three of them landed within 0.2 V on a 10k biasing resistor.  Of the three that were outside this range, only one was so far off it couldn't be used.