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Tayda... What's safe to buy there vs. what to avoid???

Started by Leevibe, March 18, 2014, 08:49:11 AM

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sturgeo

No they are - as you would expect but not in the given range of true J201s

HailToTheBlues

Quote from: sturgeo on July 03, 2014, 09:55:28 AM
Sorry they are Vgs, so basically, yup avoid J201s from Tayda!

ok then, thanks for warning me!

selfdestroyer

Quote from: sturgeo on July 03, 2014, 10:06:40 AM
No they are - as you would expect but not in the given range of true J201s

Unfortunately this is not always the case. I have had success with them lately. I really think it depends on the batch they get from their supplier. It really is a crap shoot.

Cody

pickdropper

Quote from: sturgeo on July 03, 2014, 10:06:40 AM
No they are - as you would expect but not in the given range of true J201s

Ah, so the voltages are negative.
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pickdropper

Quote from: selfdestroyer on July 03, 2014, 10:55:18 AM
Quote from: sturgeo on July 03, 2014, 10:06:40 AM
No they are - as you would expect but not in the given range of true J201s

Unfortunately this is not always the case. I have had success with them lately. I really think it depends on the batch they get from their supplier. It really is a crap shoot.

Cody

I think this is true.  But considering that Small Bear still sells them, I would be inclined to go there (although I realize they aren't as good of an option if you aren't in the US).
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selfdestroyer

Quote from: pickdropper on July 03, 2014, 11:09:57 AM
Quote from: selfdestroyer on July 03, 2014, 10:55:18 AM
Quote from: sturgeo on July 03, 2014, 10:06:40 AM
No they are - as you would expect but not in the given range of true J201s

Unfortunately this is not always the case. I have had success with them lately. I really think it depends on the batch they get from their supplier. It really is a crap shoot.

Cody

I think this is true.  But considering that Small Bear still sells them, I would be inclined to go there (although I realize they aren't as good of an option if you aren't in the US).

I do agree with that, I just add 4 to 6 with each Tayda order and test them when I get them. If they are good then its a win, if they are out of spec then I bag them and find other uses for them. I wish DIYSB still sold J201's, I got a nice batch of 40 from them 2 months ago.

Cody

HailToTheBlues

Is there any equivalent to j201 to put in a weener project? i think i read that it was difficult to swap it for other model.

GermanCdn

Quote from: selfdestroyer on July 03, 2014, 10:55:18 AM
Quote from: sturgeo on July 03, 2014, 10:06:40 AM
No they are - as you would expect but not in the given range of true J201s

Unfortunately this is not always the case. I have had success with them lately. I really think it depends on the batch they get from their supplier. It really is a crap shoot.

Cody

Yeah, I had a really good batch from them when Chi_boy first put out his boards for the Tweedy and Blackbird, I think out of 40 I had one bad one.  Haven't ordered any lately, as I cleaned out Aron's stash last time when I ordered the Taptation chips (which came with out of spec digital pots).

Long story short - it's a crapshoot on the FET end of things.  I bought 20 2N5952s from them, managed to get two quad sets and three twin sets out of them.  Probably couldn't replicate that success again if I tried.
The only known cure in the world for GAS is death.  That's my story, and I'm sticking to it.

alanp

If the FETs bias up in circuit, then they are usable. If it's at the range of the trimmer, well, that's why we have trimmers and not fixed resistors.

So buy from the sources posted, but do not throw away J201's if they are out of spec -- you might yet find that they work in-circuit.
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marauder

Quote from: sturgeo on July 03, 2014, 09:55:28 AM
Sorry they are Vgs, so basically, yup avoid J201s from Tayda!

If the FET tester is based on the Geofex matcher, then it doesn't measure VGS, but the voltage at which something or other is 10k, or something like that, can't remember exactly what it measures.  It's useful for matching, but its not VGS, its always lower.  Those are the figures I get with some of my genuine J201s.

I now use the ROG Fetzer valve FET testing circuit, which has no active components, it just measures VGS, and with a flick of a switch IDSS.  Some Tayda J201s I had measured fine for VGS, but the IDSS wasn't in the expected range.

sturgeo

Quote from: marauder on July 03, 2014, 02:48:47 PM
If the FET tester is based on the Geofex matcher, then it doesn't measure VGS, but the voltage at which something or other is 10k, or something like that, can't remember exactly what it measures.  It's useful for matching, but its not VGS, its always lower.  Those are the figures I get with some of my genuine J201s.

I now use the ROG Fetzer valve FET testing circuit, which has no active components, it just measures VGS, and with a flick of a switch IDSS.  Some Tayda J201s I had measured fine for VGS, but the IDSS wasn't in the expected range.

Ahh, thank you, it is based on the Geofex matcher, it does refer to the measured voltage as Vgs but as you say, probably at different parameters to the datasheet. Heres the info for those interested: http://www.geofex.com/article_folders/fetmatch/fetmatch.htm

I've not yet built any JFET pedals, just bought some to measure and see how they vary, as mentioned they can hopefully be biased, some are relatively close and if bought in larger batches I'm sure you'll get a better selection and hopefully no DOA ones.

As i'm in the UK unfortunately Small Bear isn't really an option, SMD adapter boards are next on my OSH Park order!

m-Kresol

Any experiences with their rotatry switches? I need some for the meatball build and thought I might go with theirs
I build pedals to hide my lousy playing.

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muddyfox

I bought some from ebay and they work fine. It's not actually soldered to the board yet (too many boards in the works  ::) ) but I've tested continuity and it's all good. I bought from this guy here

http://www.ebay.com/itm/5-3-Pole-4-Position-PANEL-Wiring-ROTARY-SWITCH-3P4T-/390363700194?pt=LH_DefaultDomain_0&hash=item5ae37d5be2

micromegas

#73
Sorry to resurrect this thread.

Has anyone had a bad experience with Tayda's bjts like 2n3904 & 2N3906? They say those are Fairchild and I wanted to buy a bunch of them..
'My favorite programming language is solder' - Bob Pease

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flanagan0718

Quote from: micromegas on August 26, 2014, 02:37:01 AM
Sorry to resurrect this thread.

Has anyone had a bad experience with Tayda's bjts like 2n3904 & 2N3906? They say those are Fairchild and I wanted to buy a bunch of them..

I've used a ton of them. Only had one bad 2n3904 and it was probably my fault.