Need source for 2sj109 jfet's

Matched pair.

mlloyd1,

I thought that the 2SJ109 was a pair of matched JFET's in one package. :confused:

Woody,

If you find a source, please let me know. I would be interested in buying 5-10 pieces as well. I remember seeing them available somewhere--can't remember. But, I think that they were ~$4.00 each. I am planning on experimenting with the Zen by building a differential JFET input stage.

Thanks,
 
Re: Matched pair.

You are right, each package is a pair of matched JFETs. I wasn't sure if the poster wanted matched 2SJ109 :) Maybe he is paralleling them for really low noise?
mlloyd1

Woody: I have recently bought GR grade from MCM Electronics. DO you know what IDSS grade you need?

stadams said:
mlloyd1,
I thought that the 2SJ109 was a pair of matched JFET's in one package. :confused:
 
I see it's time for the twice-per-decade resurrection of this
thread.

I've used "the Google" and tried a fair bit to get ahold of some
2SK389 and 2SJ109 to make a preamp. But no luck so far.

Anyone know where I can get a few of these babies - say 10
each so I can match them? Or, 2 each but expected to be
matched if the cost is over $1 or so.

Thanks.

Tried:
Digikey
Mouser
Linear Systems (have analog to '389 but not '109)
Newark
Allied
Borbeley
MCM
the first few hits on google....
 
Anyone know where I can get a few of these babies - say 10
each so I can match them? Or, 2 each but expected to be
matched if the cost is over $1 or so.

Really ?? :D :D :D

Sorry I usually keep myself away from making cynic posts, but are you serious??? If your search found this prehistoric thread, then you also found the unsuccessfull group buy thread, no?

Man, to get these parts you have to kill for. 1$ :D I know of 3 sources at the moment, all at 10$+.

http://www.bluestar-online.com/2SK389BL_K389BL_p/2sk389bl.htm

By the way, why do you want matched ones? That completely misses the point in using single die jfets if you parallel them again? Or do you want just perfect channel balance?

All the best, Hannes
 
So... here's how it goes.

I do a search.

It turns up a bunch of threads.

I see this one and look thru it. It's really old... so one logical
conclusion one can draw is that there is no longer much trouble
getting the parts. So I make a post that is reasonable given
that info.

THen I see the one about the group buy. And my hopes fall.

On the multiple parts, I want to have the same gain on the two
channels as you guessed. Thanks for the link.
 
I placed an order at Bluestar for 109s and 389s. They have
no 109s. So that does me no good since my project requires
both.

I guess it's not on.

Linear answered me and they said they plan to fab a 2SJ109
replacement but they can't say when, other than "sometime
perhaps in the next couple years". They already fab a
2SK389 replacement and I can say they work very nicely in
my "Xono Clono". So maybe I wait for "a year or two".
Apparently like a lot of other people.
 
Hannes,

Could you please write the full part numbers for these
replacement devices for me? I'm not an analog designer.

Is there a single device analog to the 2SJ109? Because
there are single analogs to the 2SK389, which I'm sure you
know is the 2SK170. I guess I'm wondering why not used
matched paris of 2SK170 and it's P-channel counterpart.
I'm guessing the answer is there is no single 2SJ109...

Thanks,

W.
 
wayne325 said:
Hannes,

Could you please write the full part numbers for these
replacement devices for me? I'm not an analog designer.

Is there a single device analog to the 2SJ109? Because
there are single analogs to the 2SK389, which I'm sure you
know is the 2SK170. I guess I'm wondering why not used
matched paris of 2SK170 and it's P-channel counterpart.
I'm guessing the answer is there is no single 2SJ109...

Thanks,

W.


Hi Wayne,

There is single analog to the 2SJ109, which is the 2SJ74. I am surprised you did see this info in your seach, such as the infamous group buy thread. But you should note that the max VGDS is lower for the singles, K389 (-50V), K107 (-40V), J109 (30V), J74 (25V), and use them with cautions. The 2SJ109 also pops up on the eBay, usually charging for a premium over the 2SK389.

Best Regards,
Edward Tam