J201 Nch J-fet's anyone?

[DavidU]

Anyone have any J201 Jfet transistors lying around?

[AdrianF]

No I dont but have you looked on www.ti.com (http://www.ti.com) ? Have a look through the samples. You might get some free ones;)

Adrian

[Jeffkop]

Hi Dave

I dont have any J201's however I may be able to get 1 if I ask my old business partner. I know much of the avionics designed in the 70's and 80's favoured this fet in audio stages and instrumentation amplifiers in VOR, localiser and glideslope ccts . We did have a couple stock. I will ask for you.

If no better substitute can be found then, its not ideal however an MPF102 can be substituted for the 201 but will probably require an increase in the source resistance of the circuit and this will tend towards less gain. If gain isnt a big issue then it could be your baby, if gain is an issue then perhaps bypass the source resistor with a capacitor, but gain will vary with frequency, with higher having more gain.

Just went looking Dave ... Farnell have them in stock http://au.farnell.com/fairchild-semiconductor/j201/transistor/dp/1017715?crosssellid=1017715&crosssell=true&in_merch=true&

[DavidU]

Thanks Jeff, they are getting harder to find these days. I usually buy 100 at a time.The tonal characteristics are the important thing for me and gaining up a MPF 102 was not quite right, even a 2N5457 is difficult to find.
I believe J201 have not been manufactured for a few years.

[Jeffkop]

Hi again Dave .. did you see the link in my previous post .. Farnell have 21800 of them

[DavidU]

Nice ! Thanks.I chew through these Jfets.
I also found lots of 200 avail from US Ebay.

[Bassnut]

Whaa, semiconductors in a musical audio product?, even FETs?, what about proper valves mate, sheesh :P, FETs are just pretendy valves ;):lol:.