# Future of the J201 - Moving forward



## Robert

As everyone is aware by now, through-hole J201s are obsolete and obviously aren't making a comeback.    It seems like even the dark corners of the net have run dry.

In the past, when possible, I have tried to include both through-hole and SMD pads for designs that require J201, 2N5457, 2N5485, etc...   Some designs are simply too complex to allow this while keeping the board within reasonable dimensions.   (or it just looks plain messy)

The majority of the issues reported here with builds involving through-hole J201s has ended up being fake/poor spec transistors, so most are resorting to SMD transistors with a SOT23 adapter board.

*This brings me to my question...*

From this point forward, when a design doesn't lend itself to "both", should we just omit the through-hole pads and go with SMD pads for the hard-to-find JFETs?
If everyone is using an adapter board _anyway, _it seems silly to keep beating a dead horse.


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## reubenreub

I've honestly given up on most through-hole JFETs and have stocked up on SMD J201s, 5457s, and 4393s. It took a bit of getting used to soldering them but I've been so much happier with the results.


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## Nostradoomus

I’m very much fine with SMD...but I am also prepared and experienced enough to do so. The hard bargain is for the beginners but maybe run an option as you do with the FV-1 and have them pre soldered? Not sure you want to take that on as well though


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## Robert

The beginners are _usually _the ones who aren't aware of the situation with through-hole J201s and end up getting burned buying fakes....

So on one hand it might deter some of the first-time builders, but on the other hand it could raise awareness to the situation before money is wasted.


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## Mourguitars

Can someone post a link to the Jfet sockets and sockets for the diodes  to swap in and out, i want to buy the right ones..

Mike


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## Nostradoomus

Mourguitars said:


> Can someone post a link to the Jfet sockets and sockets for the diodes  to swap in and out, i want to buy the right ones..
> 
> Mike











						40 Pin 2.54mm DIP SIP IC Sockets Adaptor Solder Type
					

Lead Free - Get It Fast - Same Day Shipping




					www.taydaelectronics.com


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## Barry

I think we should embrace learning to solder SMD is the future


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## Mourguitars

Nostradoomus said:


> 40 Pin 2.54mm DIP SIP IC Sockets Adaptor Solder Type
> 
> 
> Lead Free - Get It Fast - Same Day Shipping
> 
> 
> 
> 
> www.taydaelectronics.com



Thanks !


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## temol

I use almost exclusively MMBF/MMBFJ transistors but when possible  I prefer to have through hole footprint. It's easier to swap transistors soldered to adapters  than solder-desolder smd transistor.  But I do not see any problem with "smd only" path. 

T.


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## Many__Of__Horror

It will force me to learn SMD soldering, I'm game


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## phi1

I’m all for SMD pads on the pcbs going forward. 

I’ve seen several places selling smd converions boards, which is a great option in the meantime or for building on vero board or bread boarding, which I often like to do. But, I’m surprised I haven’t seen anywhere selling a finished package (smd jfet soldered to conversion board with lead pins). This would be a great replacement option for beginners or  builders who just don’t want to mess with it. I’d think there’d be a market for it even priced at a few bucks per jfet. If done at significant volume, chip mounting, with reflow solder and vcutting could make the process very quick for the manufacturer. Anybody heard of something like this?


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## niketplos

phi1 said:


> I’m all for SMD pads on the pcbs going forward.
> 
> I’ve seen several places selling smd converions boards, which is a great option in the meantime or for building on vero board or bread boarding, which I often like to do. But, I’m surprised I haven’t seen anywhere selling a finished package (smd jfet soldered to conversion board with lead pins). This would be a great replacement option for beginners or  builders who just don’t want to mess with it. I’d think there’d be a market for it even priced at a few bucks per jfet. If done at significant volume, chip mounting, with reflow solder and vcutting could make the process very quick for the manufacturer. Anybody heard of something like this?


guitarPCB was selling 5 packs like this a year or two ago.  https://guitarpcb.com/product/j201-factory-soldered-converter-board-5-pack-w-gold-pin-headers/

sadly not anymore.


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## Dreamlands

I've really been wanting to learn to work with SMD, so I'm game.


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## K Pedals

I’ve been putting off surface mount for awhile and I recently ran out of 2n5457 and was forced and it was way easier than I thought I’d be... 
but yeah I got burned a lot first starting out with J201 and 2N5457s... and none of my builds worked and I couldn’t figure out why... it would probably save beginners a lot of discouragement to just have SMD....


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## phi1

Last year I spent a few weeks breadboarding and then building an overdrive design based around j201s I got from eBay before I really understood the situation. I was really happy with the result but now sadly I can’t duplicate it with good smd ones because I now realize the ebay ones measure way out of spec. So in any case, I think education is key. Maybe a note would be helpful on existing projects’ product page or build docs.


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## Tremster

I use the adapters and treat these like through holes - because I can't measure and match the SMD ones. I'd be afraid soldering unmeasured and untested transistors onto the board.


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## Chuck D. Bones

I'm stockpiling thru-hole JFETs.  My last source of J201s dried up, but there are alternatives.  I've done some SMD soldering and I'm still not very good at it.  I've watched the pros hand-solder SMD boards and it's a slow painstaking process to do it right.  SMD boards are best assembled by machines. At the very least they should be soldered in a reflow oven.  Given a choice, I'll pick thru-hole every time.  If you can possibly manage it, dual footprint would be appreciated.  When the board I want isn't available, I always have Plan B: Vero. 
Yeah, that lone thru-hole vote is me.


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## jubal81

InterFet is making through-hole J201s and you can buy them at Mouser. Only drawback is they are $3.50 each.

Personally, I've moved on. I actually prefer soldering SOT23 and there are a lot of better JFET options out there than the J201, like the 2SK880. Of course the problem with legacy designs is people want to build them part-for-part.


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## Flying

I came to the party too late to stock up on through hole FETs, and so avoided all FET projects until recently when I discovered SDM soldering isn't as bad as I feared, so I'm all for SMD FETS now.

Would it be possible to design a utility board to test SMD JFETs for matching purposes?


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## Nostradoomus

Flying said:


> I came to the party too late to stock up on through hole FETs, and so avoided all FET projects until recently when I discovered SDM soldering isn't as bad as I feared, so I'm all for SMD FETS now.
> 
> Would it be possible to design a utility board to test SMD JFETs for matching purposes?



These cheapo components testers are pretty slick and have pads for SMD.


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## Robert

I certainly won't call it the best or easiest way, but I just solder them to one of the SOT23 adapters (with pins installed) when I want to test them on my DCA75.


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## Nostradoomus

A DCA55 or 75 is definitely on my list. The dinky component tester only goes so far. Its fine for SMD Fets but doesn’t give me a clue about old GE components haha


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## the_grumpy_gnome

SMD-only is logical and not going to be an issue for many, but I'm concerned that people new to pedal building or _new to soldering_ are going to have a lot of trouble with SMD stuff.  I suggest that projects which require them include a warning on the project page, as well as possibly a supplemental alignment illustration in the project .pdf.


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## Flying

Regarding SOT23 testing, I've just discovered Peak do an adapter: https://www.peakelec.co.uk/acatalog/pca23-peak-component-adapter-sot23.html#SID=27

I wonder if the clip is generally available and could be built into a JFET matching board?


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## Mourguitars

So....the J201's i bought off eBay most likely  not be good ?  I went to Tadya and put in my cart the SMD 201"s for my next order and ill get the boards here from PedalPCB any other JFET's i need to worry about be hard to obtain with out paying a arm and leg for ?

It is what is is on parts and don't mind using SMD unfortunately its the trend going forward ... The KTR went SMD i under stand that , but a lot of us are old school on things , im that way but learning new things keeps me sharpe..well, i would like to think so anyway ! lol

Mike


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## phi1

2N5457 is basically the same situation as J201, as far as I can tell.


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## Nostradoomus

Yeah any JFET through hole on eBay is pretty dicey unless it’s currently in production in which case it’s still kinda dicey.


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## Mourguitars

Nostradoomus said:


> Yeah any JFET through hole on eBay is pretty dicey unless it’s currently in production in which case it’s still kinda dicey.




What i thought...i guess i can socket them

Mike


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## K Pedals

Mourguitars said:


> What i thought...i guess i can socket them
> 
> Mike


Yeah I’d definitely socket ‘em...


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## Flying

phi1 said:


> 2N5457 is basically the same situation as J201, as far as I can tell.


Is it, damn, I already had some 2N5457s and just got 50 J201s!


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## Flying

It only dawned on me recently that different makes have different product codes for the SMD J201:

On semiconductor: MMBFJ201
InterFet: SMPJ201
Vishay: SST201

Maybe we could have a list? I've been waiting two months for MMBFJ201's to be available in the UK, if I'd twigged earlier that the MMBFJ201 was only On semiconductors product code, not the product code for all SMD J201s I might have been able to get some earlier.


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## Flying

Nostradoomus said:


> These cheapo components testers are pretty slick and have pads for SMD.


Sorry, I completely missed your post Nostradoomus, I have a similar device






This is the results I get for a MMBF5458... Now I need to go a learn what it's telling me! A quick look at the data sheet and I'm none the wiser 

(The JFET was pushed down onto the pads to get the reading)


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## Chuck D. Bones

This gives you one point on the transfer function.  The Vg displayed is actually -1.0V.  It looks like a healthy device, that's about all we can tell.  That tester looks pretty slick, I just ordered one.


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## Flying

Thanks Chuck D. Bones,

I feel I'm pulling this thread off topic so will start a new thread regarding JFETS.


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