Author Topic: J201 substitute  (Read 10832 times)

mrbridgewater

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J201 substitute
« on: April 02, 2014, 09:57:20 PM »
Hey! I was wondering what the best substitute would be for a J201 JFET? They are either expensive or kind of difficult to find. It's the last part of my order that I need and the only one that the store I'm using is out of.

Thank you!

jimilee

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Re: J201 substitute
« Reply #1 on: April 02, 2014, 10:18:37 PM »
Pin out is different, and it depends on the application but recently I used a j201 in place of an mpf102 beacis has a great Pinout guide for most trannies made up until a few years ago. It's a good starting place.
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RobA

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Re: J201 substitute
« Reply #2 on: April 02, 2014, 10:41:47 PM »
Hey! I was wondering what the best substitute would be for a J201 JFET? They are either expensive or kind of difficult to find. It's the last part of my order that I need and the only one that the store I'm using is out of.

Thank you!
It depends on the usage. What circuit are you working on?
Affiliations: Music Unfolding (musicunfolding.com), software based effects and Rock•it Frog (rock.it-frog.com), DIY effects (coming soon).

midwayfair

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Re: J201 substitute
« Reply #3 on: April 03, 2014, 07:33:13 AM »
It depends on what you're building.

If you're using it in a buffer, there are better FETs. If you're building it in a boost, there MAY be better choices.

If you're building it in an overdrive, there isn't really a good sub for the J201. Their gain is much higher than almost every other FET, and their input headroom is also much lower. This means that when you're cascading them, they produce more gain AND distort easier, so you need fewer stages to achieve higher gain sounds. The closest you can get on pure gain specs without finding something truly exotic is the 2SK170, and they still only have just over half as much gain. 2SK30 is the next step down.

Also, as has been noted in many threads in recent years, through-hole FETs are obsolete and consequently difficult to source. They're going to be expensive. But it's a 50c part ... not terribly expensive in the grand scheme of things. You can also buy SMD J201s and use an adapter board. Chromosphere posted about those recently.

Jimi: The pinout of the MPF102 is identical to the J201. :-\
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peAk

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Re: J201 substitute
« Reply #4 on: April 03, 2014, 07:41:10 AM »
You could always go this route:

http://www.madbeanpedals.com/forum/index.php?topic=14492.0


cheap as hell!

ggarms

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Re: J201 substitute
« Reply #5 on: April 03, 2014, 09:24:17 PM »
Or check out chromosphere's SMD j201 with adapter board option. I just snagged 20 of em-His prices are good too! I think it works out to approximately 25 cents each with the adapter board, and you don't have to worry about them being out of spec like the j201's from the parts store who must not be named



http://www.diyguitarpedals.com.au/shop/index.php?main_page=product_info&cPath=6&products_id=52

Clayford

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Re: J201 substitute
« Reply #6 on: April 03, 2014, 09:34:20 PM »
I'll vouch Chromosphere all day every day. Great guy to deal with. Don't be scared, use a good set of tweezers, and pre-tin. Oh and watch the video.

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chromesphere

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Re: J201 substitute
« Reply #7 on: April 03, 2014, 10:11:25 PM »
Thank you friends!  I have another !@#-load of adapter pcb's coming in the next few weeks as i'm getting a bit low, so if you miss out don't worry, there's more coming and they will be a permanent item on the store.
Cheers
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jimilee

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Re: J201 substitute
« Reply #8 on: April 03, 2014, 10:14:30 PM »

Jimi: The pinout of the MPF102 is identical to the J201. :-\
My misake, I was working with a j201 an mpf102 and nte458 Got them confused here.
Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.

mrbridgewater

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Re: J201 substitute
« Reply #9 on: April 05, 2014, 07:31:00 PM »
Hey! Sorry I took so long to get back. I'm working on the Sharkfin. I finally got around to getting the PCB and am about to order parts. Thanks again!

midwayfair

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Re: J201 substitute
« Reply #10 on: April 05, 2014, 09:15:00 PM »
Hey! Sorry I took so long to get back. I'm working on the Sharkfin. I finally got around to getting the PCB and am about to order parts. Thanks again!

In that case, definitely get the J201s. They'll have a wider switching range than other JFETs, probably the reason Bean liked them the best.
Myself's music & things I make: http://jonpattonmusic.com. My band: http://midwayfair.org. PCBs of my designs from: http://www.1776Effects.com (Bearhug Comp & Cardinal Harmonic Trem); http://www.jmkpcbs.com (Hamlet+ delay & Blue Warbler envelope vibe); Snow Day OD/Flabulanche: www.madbeanpedals.com

mrbridgewater

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Re: J201 substitute
« Reply #11 on: April 05, 2014, 09:42:15 PM »
Sounds like a plan. It looks like I should just buy a bunch in one go, so I have the part on hand for future builds. I just don't like the cost of shipping on electronics components for small orders. Thanks for all the help.

chromesphere

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Re: J201 substitute
« Reply #12 on: April 05, 2014, 09:48:48 PM »
My webstore is pretty cheap for postage as it's untracked.  You should be able to order up to 150g of components (quite a lot) for $7 untracked or if you worried about the package $21 tracked.  Tayda is probably a similar cost as well, they are pretty inexpensive for shipping.
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