# MMBF5457’s and where they at?



## Kroars (Jan 9, 2022)

So, I recently went to stock up on a few items and seemed to be having trouble finding mmbf5457’s.  Then I came across a note that they’ve been discontinued?  Anyone know what’s going on with these? Is there a spot I can pick up 100+ for a decent cost (-$0.50)? Feel like I’ve been to all the usual spots with no luck.

Thanks!

Edit: digikey says these are a direct substitute -anyone try these in place of the 5457’s?






						MMBFU310LT1G onsemi | Discrete Semiconductor Products | DigiKey Marketplace
					

Order today, ships today. MMBFU310LT1G – JFET N-Channel 25 V 225 mW Surface Mount SOT-23-3 (TO-236) from onsemi. Pricing and Availability on millions of electronic components from Digi-Key Electronics.




					www.digikey.com


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## fig (Jan 9, 2022)

Mouser has an option to request a quote as a special order.


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## Barry (Jan 9, 2022)

Kroars said:


> So, I recently went to stock up on a few items and seemed to be having trouble finding mmbf5457’s.  Then I came across a note that they’ve been discontinued?  Anyone know what’s going on with these? Is there a spot I can pick up 100+ for a decent cost (-$0.50)? Feel like I’ve been to all the usual spots with no luck.
> 
> Thanks!
> 
> ...


Last I bought were from Quest, they still have some, but they are marked as discontinued






						Scheduled Maintenance | Quest Components
					






					www.questcomp.com


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## carlinb17 (Jan 9, 2022)

Their a little more but their on boards








						2N5457 JFET with TO-92 Adapter
					

The 2N5457 JFET in SMD format, pre-soldered to adapters for use in through-hole applications.




					aionfx.com


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## spi (Jan 9, 2022)

Have they really discontinued them or is this just supply chain issue?


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## JamieJ (Jan 9, 2022)

I know this isn’t exactly what your are after but Fuzz dog has 2n5457 in TO-92 which I placed an order for a load last week. I’m trusting that they are legit but I haven’t received them yet.









						2N5457 N-Channel JFET
					

2N5457 N-Channel JFET These are getting pretty scarce, so here at FD Towers we jumped on an opportunity to get major stock levels while we could. Manufacturer: Central Semicondutor Corp. Package: TO-92 Download DATA SHEET




					shop.pedalparts.co.uk


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## Harry Klippton (Jan 9, 2022)

Per storyboardist (effects layouts guy) on the Madbean forum, ON Semi discontinued them last year


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## spi (Jan 9, 2022)

Until very recently, GuitarPCB had some NOS 2n5457s, but have gone dry.

I thought about buying some, but didn't because I figured the the smd versions would still be around for a while.

Update:  looks like pedalhacker still has some in stock.


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## jjjimi84 (Jan 9, 2022)

They are in my butt


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## fig (Jan 9, 2022)

jjjimi84 said:


> They are in my butt


Well fart me a quad set bro.


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## jjjimi84 (Jan 9, 2022)

fig said:


> Well fart me a quad set bro.


I had an incident with packaging and those little fuckers went everywhere.


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## Bio77 (Jan 9, 2022)

Harry Klippton said:


> Per storyboardist (effects layouts guy) on the Madbean forum, ON Semi discontinued them last year


This is what I've heard, too.  I recently bought a few 2N5457 made by Central Semiconductors on Mouser.  Maybe they will make more next year.


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## Kroars (Jan 9, 2022)

carlinb17 said:


> Their a little more but their on boards
> 
> 
> 
> ...


Yeah, I’ve got a few of those where they fit.  Some boards are a little cramped for them, to me anyway.  Thanks!


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## Kroars (Jan 9, 2022)

Harry Klippton said:


> Per storyboardist (effects layouts guy) on the Madbean forum, ON Semi discontinued them last year


Man, I don’t wanna like that post…. But thanks for the clarification.


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## Kroars (Jan 9, 2022)

jjjimi84 said:


> I had an incident with packaging and those little fuckers went everywhere.


Oh Jesus, I can only imagine.  I knocked one off the bench last night, didn’t even bother looking for it.  If I have trouble finding a dropped ge diode, I’m never gonna find an smd fet.


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## Harry Klippton (Jan 9, 2022)

Kroars said:


> Man, I don’t wanna like that post…. But thanks for the clarification.


I was expecting them to stick around for a while in the sot-23 package too but oh well I guess


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## Kroars (Jan 9, 2022)

Barry said:


> Last I bought were from Quest, they still have some, but they are marked as discontinued
> 
> 
> 
> ...


Awesome, that’s exactly what I needed! Thank you very much.  I went through four pages on the google and nothing….  Out of curiosity I noticed these have an “LT1” at the end, I’m guessing they’ll work for our needs?  Thanks again!!

Edit:  I quickly scanned through the data sheets and they seem to jive.  Maybe the LT1 is ON Semi’s code and the regular 5457’s are FSC.  Also, now that I google MMBF5457LT1 I’m finding a lot more in stock in other sites.  Maybe it’s just FSC that’s discontinuing them.  Hopefully ON Semi’s are just as good, mojo and all.  Although doesn’t ON own FSC?


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## Bricksnbeatles (Jan 9, 2022)

spi said:


> Until very recently, GuitarPCB had some NOS 2n5457s, but have gone dry.


Dang. I only bought 10 of them because I thought they’d be around for a while since they’ve been in stock there for a full two or three years I believe. Should have gone for 50 or more.


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## Barry (Jan 9, 2022)

Kroars said:


> Awesome, that’s exactly what I needed! Thank you very much.  I went through four pages on the google and nothing….  Out of curiosity I noticed these have an “LT1” at the end, I’m guessing they’ll work for our needs?  Thanks again!!
> 
> Edit:  I quickly scanned through the data sheets and they seem to jive.  Maybe the LT1 is ON Semi’s code and the regular 5457’s are FSC.  Also, now that I google MMBF5457LT1 I’m finding a lot more in stock in other sites.  Maybe it’s just FSC that’s discontinuing them.  Hopefully ON Semi’s are just as good, mojo and all.  Although doesn’t ON own FSC?


I think their going away, the Quest site list what they have in stock as discontinued


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## Barry (Jan 9, 2022)

I noticed @PedalPCB adapterboards aren't dual sided anymore, so I guess we're just install the 5457's flipped around the board layouts


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## DAJE (Jan 9, 2022)

I have two of the Aion adaptor board 5457s left. I don't need any soon but I'm thinking about doing a Pharmacist which requires four 5457s. So, alternatives would be good.


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## jimilee (Jan 9, 2022)

DAJE said:


> I have two of the Aion adaptor board 5457s left. I don't need any soon but I'm thinking about doing a Pharmacist which requires four 5457s. So, alternatives would be good.


J201s can be used. You may have to increase some resistance. Tayda has a little over 5K.









						MMBFJ201 SOT-23 JFET N-CHANNEL TRANSISTOR J201 SMD
					

Fairchild - Get It Fast - Same Day Shipping




					www.taydaelectronics.com


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## Robert (Jan 9, 2022)

Barry said:


> I noticed @PedalPCB adapterboards aren't dual sided anymore, so I guess we're just install the 5457's flipped around the board layouts



It wasn't necessary.    The component libraries that were floating around the net a few years ago had the drain and source reversed on one of them (either MMBFJ201 or MMBF5457, I can't recall)...    This was incorrect but went unnoticed because the drain and source are interchangeable anyway.

I left the J201 marking on the adapter just so it isn't confused with some other SOT23 pinout but you can use them with either, no need to reverse anything.


I have a few hundred MMBF5457's that I've been meaning to add to the site I just keep forgetting.


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## DAJE (Jan 9, 2022)

0.48US $ |10pcs 2SK246 K246 TO 92 2SK30A 2SK117 2SK241 2SK439 2N5486 2N5460 2N5484 2N5485 2N5457 2N5088 2N5089 2N6517 2N6027 2SK170 2SK105|Integrated Circuits|   - AliExpress
					

Smarter Shopping, Better Living!  Aliexpress.com




					www.aliexpress.com
				




For what it's worth, I bought 20 x 2N5089s from this seller, they test in spec and I've used them in a couple of pedals which are working as expected. I've bought a few other items from this seller, all working.

I just bought 20 x 2N5457s. If they turn out to be duds, OK, but I'm reasonably optimistic. Not all Chinese sellers are dodgy, in general I've found that as long as you have some critical reasoning skills, you can avoid most of the rip-offs.


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## Barry (Jan 9, 2022)

DAJE said:


> 0.48US $ |10pcs 2SK246 K246 TO 92 2SK30A 2SK117 2SK241 2SK439 2N5486 2N5460 2N5484 2N5485 2N5457 2N5088 2N5089 2N6517 2N6027 2SK170 2SK105|Integrated Circuits|   - AliExpress
> 
> 
> Smarter Shopping, Better Living!  Aliexpress.com
> ...


I've used that seller as well and had good results


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## temol (Jan 10, 2022)

DAJE said:


> I just bought 20 x 2N5457s. If they turn out to be duds, OK, but I'm reasonably optimistic. Not all Chinese sellers are dodgy, in general I've found that as long as you have some critical reasoning skills, you can avoid most of the rip-offs.



I bought MMBF5457 from them - no luck, all out of specs.


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## thesmokingman (Jan 10, 2022)

saw this post, saw my parts list for my delay needing a 5457 ... immediately ordered 8 from aionfx 

you guys gotta quit using up all the good stuff on your crappy builds


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## finebyfine (Jan 10, 2022)

DAJE said:


> 0.48US $ |10pcs 2SK246 K246 TO 92 2SK30A 2SK117 2SK241 2SK439 2N5486 2N5460 2N5484 2N5485 2N5457 2N5088 2N5089 2N6517 2N6027 2SK170 2SK105|Integrated Circuits|   - AliExpress
> 
> 
> Smarter Shopping, Better Living!  Aliexpress.com
> ...



I've bought 2n5457s from this seller before and they're just a shy out of a spec but more than fine for pedals. My ATMega transistor tester didnt recognize them as JFETs but my DCA75 did.


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## DAJE (Jan 10, 2022)

finebyfine said:


> I've bought 2n5457s from this seller before and they're just a shy out of a spec but more than fine for pedals. My ATMega transistor tester didnt recognize them as JFETs but my DCA75 did.



I have a DCA75 too, went a bit crazy with the spending during one of the interminable lockdowns. The bag of 20 x 2N5089s all measured around hFE 350, which is about right for them, maybe slightly low but - as you say - fine for pedals. And they sound great where I used them, five of them in a Carcass (Carcosa) pedal, so I'm entirely satisfied with them.


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## thesmokingman (Jan 11, 2022)

thewintersoldier said:


> I think we are in the final stretch of the golden age of diy pedal building. Many thru hole transistors, jfets and ICs are either obsolete or entering EOL. Even alot of smd parts are going the way of the dodo. How long before thru hole resistors and caps are phased out? The future is smds, hot air stations, solder paste and ovens. Get it in while we can.


I should have insisted on PIFmas this year to blow out the cold storage pcbs ... there's shit in there I have no intention of doing and by the time I get around to it there won't be parts left to do it with


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## Kroars (Jan 12, 2022)

thewintersoldier said:


> I think we are in the final stretch of the golden age of diy pedal building. Many thru hole transistors, jfets and ICs are either obsolete or entering EOL. Even alot of smd parts are going the way of the dodo. How long before thru hole resistors and caps are phased out? The future is smds, hot air stations, solder paste and ovens. Get it in while we can.


Try this guy. His names Mike, good dude.  I’ve been working with him as of late and already received numerous orders that were all professionally packed and shipped quickly.  He’s got literally 1,000’s more components than what he has listed on eBay, so if you don’t see something you need just send him a message.  He’s also got thousands of smd fets 5457’s, 4393 etc.  Mikes super easy to work with and is more than happy to negotiate price.  He literally said to me he’s got more products coming in then going out at this point and needs to reverse that asap.  Seems like the perfect solution to our predicament. 

Also, he’s got a money back guarantee.  









						myparts2468 | eBay Stores
					





					www.ebay.com


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## finebyfine (Jan 12, 2022)

thewintersoldier said:


> I think we are in the final stretch of the golden age of diy pedal building. Many thru hole transistors, jfets and ICs are either obsolete or entering EOL. Even alot of smd parts are going the way of the dodo. How long before thru hole resistors and caps are phased out? The future is smds, hot air stations, solder paste and ovens. Get it in while we can.



This is one of those pedal opinions that I agree with just a hair more than I disagree with it and flip flop every other day.

We all know the negative side any time we look for obsolete components, so let me share some of the things that make me excited to be making pedals now:

PCB Fabrication and SMT assembly is constantly getting cheaper and faster. Feel like you don't have the time to breadboard a circuit? (That's a lie, but) Embrace hyper-globalism instead of despairing in it! Have a pcb of it show up in your mailbox in a week for a few bucks instead.
DSP is constantly getting better and more accessible to hobbyists. You can run Faust (!!!!) programs on ESP-32s that cost a buck (although the $25 Teensy might be a better option). Garageband, software free with an OS, _still_ has amp emulators that are better than modeling amps you can buy at a guitar center, and I say this as a Katana owner.
I probably thought a TO-92 was crazy small the first time I soldered one. SOT-23s don't feel so tiny to me anymore (just in time for most manufacturers to have been moving to smaller packages for years)
For all we covet them for, germanium transistors are the ones that killed tubes, not silicon transistors.
I like being challenged in this hobby because it makes it keep feeling new. The obsolete parts that we use a lot in pedals are being replaced by something in the industries that dictate manufacturing, even if not a direct substitute, and learning how to cobble that shit together to keep making pedals sounds like exactly the kind of fun challenge I like.
Less time to build pedals is more time to find new reasons to avoid practicing 
All of that said, bending resistor leads and dropping them into PCBs is practically meditation for me. I could gladly do it for hours.  Stepping further and further away from the physical elements I enjoy like that is a bummer.


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## Kroars (Jan 12, 2022)

finebyfine said:


> This is one of those pedal opinions that I agree with just a hair more than I disagree with it and flip flop every other day.
> 
> We all know the negative side any time we look for obsolete components, so let me share some of the things that make me excited to be making pedals now:
> 
> ...


Nothing better than a good audiobook and a couple pcbs


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## JamieJ (Jan 13, 2022)

If it got to that level I think I would just focus on designing my own PCBs for enjoyment  for every build. Rather than the fun of populating and actually building the board.


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## fig (Jan 13, 2022)

I've enjoyed the SMD stuff so far.
_They'll never take my breadboard!_
SMD components are cheaper, and take up less space.
_I have enough thru-hole to last me! I just need to rent that mini warehouse for my passives._
DSP is good, just different.
_I just bought a $3K tube amp!_
You can still build analog circuits with SMD.
_There goes the badass clipping options._


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## Kroars (Jan 13, 2022)

fig said:


> I've enjoyed the SMD stuff so far.
> _They'll never take my breadboard!_
> SMD components are cheaper, and take up less space.
> _I have enough thru-hole to last me! I just need to rent that mini warehouse for my passives._
> ...


Ooh! Which amp?


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## fig (Jan 13, 2022)

Fender '64 CDR. 20 watts of tubular bliss. I'm not saying it's the last amp I will buy, but it's certainly the only one I really need covet.


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## Harry Klippton (Jan 13, 2022)

fig said:


> Fender '64 CDR. 20 watts of tubular bliss. I'm not saying it's the last amp I will buy, but it's certainly the only one I really need covet.


How many amps have you been through in the last 2 years? 😰😬😂


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## fig (Jan 13, 2022)

All of them.

I never had a lot of time for music in my 20s....30s....40s.....50s.....work....kids....life.....but now! No kids, no life! Very little work involvement! Yay! (until the proverbial cement truck hits me)


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## Kroars (Jan 13, 2022)

fig said:


> Fender '64 CDR. 20 watts of tubular bliss. I'm not saying it's the last amp I will buy, but it's certainly the only one I really need covet.


Very cool, congratulations!  I’d love an old fender.  After 30 years of playing solid state amps I finally purchased my first big boy amp (Orange TH30 with an Orange PPC212c) about a year or so ago.  I was blown away by the tonal difference.  Unfortunately, I’ve yet to turn it up past about 2 (if it went to 10) because of how incredibly loud it is -I’ve never turned it off the 7.5w setting.  However, I’ve got a Fryette PS-2 on the way that I hope will help in that dept.


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## fig (Jan 13, 2022)

That's a sweet attenuator!


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## Kroars (Jan 13, 2022)

fig said:


> That's a sweet attenuator!


That’s what I hear.  When I couldn’t find one on the used market I figured that was a good sign.  Never owned one before -never needed one with solid state amps.  I’ve been told it’s important that I hook it all up correctly


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## finebyfine (Jan 13, 2022)

thewintersoldier said:


> I fully appreciate your insight, as we all have different reasons for why we love this hobby and everyone's journey is different. I like the old school. Always have, always will. It's a dying art form, I like that I can work on Amps and pedal like they did years ago. I think thru hole looks awesome. I don't need everything in a 125b. I also feel like you that there is something relaxing and fun about populating boards. I don't mind smd jfets or transistors and even some ICs. But a whole board? Not for me. I don't want a hot air station, I like the technique of soldering thru hole with an iron. I don't like digital because the future of digital is algorithms. I don't want to program 1s and 0s. I'm all about learning as well but I want to keep that analog aspect, like analog circuit with digital switching or tap tempo. But all digital?.I want loud, heavy tube amps pummeled with fuzz at house shattering levels cause at the heart of it to me, that's what rock n' roll and playing guitar is all about.


[heavy sigh] yep. exactly my thoughts unless I go out of my way to argue against it like in that post, and even then this side usually wins out


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## finebyfine (Jan 13, 2022)

thewintersoldier said:


> After reflecting on my distaste for digital effects that are programmed, I think it has to do with the fact that most of these effects change the fundamental sound of the guitar. I want my guitar to sound like a guitar, but sometimes with delay or tremolo and phaser. Many of the digital effects are more the instrument and the guitar is a mechanism to operate them. I get how some people are into ambient playing. I see myself as someone who plays guitar and not pedals. If that makes any sense 😂



That makes total sense, I mean I rattled off all of those reasons but I really only use fuzz pedals lmao


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## Harry Klippton (Jan 13, 2022)

Kroars said:


> Very cool, congratulations!  I’d love an old fender.  After 30 years of playing solid state amps I finally purchased my first big boy amp (Orange TH30 with an Orange PPC212c) about a year or so ago.  I was blown away by the tonal difference.  Unfortunately, I’ve yet to turn it up past about 2 (if it went to 10) because of how incredibly loud it is -I’ve never turned it off the 7.5w setting.  However, I’ve got a Fryette PS-2 on the way that I hope will help in that dept.


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## fig (Jan 13, 2022)

Harry Klippton said:


> View attachment 21548


I found that to be true of a JVM as well. If you're not wearing ear protection, you're doing something wrong.


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## jimilee (Jan 13, 2022)

fig said:


> I found that to be true of a JVM as well. If you're not wearing ear protection, you're doing something wrong.


I'm wearing hearing aids as a nice alternative to years of ear protection.


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## xefned (Jan 17, 2022)

Bricksnbeatles said:


> Dang. I only bought 10 of them because I thought they’d be around for a while since they’ve been in stock there for a full two or three years I believe. Should have gone for 50 or more.



Are those 2n5457s from GuitarPCB working out for you?

I recently bought a batch of 10 (at $1.69 each) and my tester shows them as BJTs, not J-FETS. His site says, "Guaranteed Genuine" and "from my own personal collection." But I ordered in Dec. 2021 and I'm concerned his personal collection ran dry and he re-stocked with some re-badged BJTs.


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## fig (Jan 17, 2022)

xefned said:


> Are those 2n5457s from GuitarPCB working out for you?
> 
> I recently bought a batch of 10 (at $1.69 each) and my tester shows them as BJTs, not J-FETS. His site says, "Guaranteed Genuine" and "from my own personal collection." But I ordered in Dec. 2021 and I'm concerned his personal collection ran dry and he re-stocked with some re-badged BJTs.


Have you reached out to Barry? I picked up 25 from him about 2 weeks ago. They read as FETs and the Idss readings were in spec, but the Vgs(off) readings were low on all samples. I imagine everyone's stash of popular THDs are thinning.


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## xefned (Jan 17, 2022)

fig said:


> Have you reached out to Barry? I picked up 25 from him about 2 weeks ago. They read as FETs and the Idss readings were in spec, but the Vgs(off) readings were low on all samples. I imagine everyone's stash of popular THDs are thinning.



I did actually, just before I posted.  Because I didn't want to seem like I was smack talking without first reaching out to him. I've been meaning to write him, just forgetful.

Just to check that my cheap transistor tester wasn't misreporting, I snipped an ancient 2n5457 from a scrapyard project and it read as a JFET. Then I tested some Aion SMT 5457s and they also read as JFET. 🤔

I didn't even ask him for a refund cuz I know it's hard to run a small business and I'm sure these will be useful for something. But I'm reluctant to use them as 2n5457s. I just wanted him to know in case he got a bum batch.

On a positive note, the quad-matched 2N5952s I got from Barry tested right and sound perfect in my Tractor Beam.


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## Bricksnbeatles (Jan 17, 2022)

xefned said:


> Are those 2n5457s from GuitarPCB working out for you?
> 
> I recently bought a batch of 10 (at $1.69 each) and my tester shows them as BJTs, not J-FETS. His site says, "Guaranteed Genuine" and "from my own personal collection." But I ordered in Dec. 2021 and I'm concerned his personal collection ran dry and he re-stocked with some re-badged BJTs.


Haven’t tested them yet. I ordered in December too I think, and since then my work bench has been blocked by boxes while my parents get some renovations done. It’ll suck if they’re bunk


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## xefned (Jan 17, 2022)

Bricksnbeatles said:


> Haven’t tested them yet. I ordered in December too I think, and since then my work bench has been blocked by boxes while my parents get some renovations done. It’ll suck if they’re bunk



Hey, no need to worry. Barry wrote me back and assured me that he tests everything before he ships. And he sent me a screenshot of his Atlas DCA55 testing one. I'll just copy-and-paste his message in here since it demonstrates the pinnacle of customer service so I don't think he'd mind.



			
				Barry@GuitarPCB said:
			
		

> Hi Matthew,
> 
> My batch of 2N5457s that I have been selling for the last 3 months are absolutely legit and work as intended in a circuit. Also if they were not I would have received hundreds of emails. You are the only one.
> 
> ...



His hunch was right; I'm using a $16 no-name transistor tester from aliexpress.com, so I definitely trust his Atlas more than my reject genero job.

In my defense, I'm not psycho, just very wary of counterfeits. The "F" logo on these is pencil thin. When I compare that to other Fairchild transistors in my stash, they use a thicker boldface *F* logo. There also seemed to be tiny micro-abrasions on the surface which made me worried they had been sanded and re-badged.


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## DAJE (Jan 17, 2022)

xefned said:


> His hunch was right; I'm using a $16 no-name transistor tester from aliexpress.com, so I definitely trust his Atlas more than my reject genero job.


I have a Peak Atlas tester and a T7 tester, I find they're both useful, but the T7 often gives screwy results for transistors. For Caps, resis, LEDs etc, the T7 is excellent.


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## Stickman393 (Jan 24, 2022)

In regards to through-hole components going away:

I'm skeptical of this train of thought.  After all, tubes haven't gone away as of yet.  BBDs we're getting harder to find, but then Coolaudio and xvive came along and started making new ones.

Through-hole J201's are still available on mouser, manufactured by interFET.  Same with 2n5457's: those are made by central semiconductor.

Remember the 90's?  Vinyl looked like it was headed the way of the dodo.  Nowadays it makes up a larger percentage of the market share than CDs.

Is this a momentary reprieve for those of us that desire these old, analog components in familiar packages?  Probably.  Partially.

The DIY community still exists...and there's certainly a demand from customers for analog gear.  The demand is nowhere near what it once was, though and that probably means that the major semiconductor manufacturers will stop making this stuff.  

But if there's still a demand...I have a feeling that smaller outfits will try to find ways to meet that demand.  There will be less to go around, likely leading to higher prices, and it's unlikely that ALL our favorite go-to components will be reproduced...but I imagine they'll be around long enough for intrepid folks to work out work-arounds for specific unobtanium parts.

I doubt through hole passives will ever stop being produced anyways.  You can slap those in screw terminal blocks like you would with a wire.  Take a 0-20mA signal and convert it to 0-10v by using a 500 ohm resistor in parallel.  Add power supply decoupling to a digital input.  

The market share will likely continue to shrink, but there will always be a fetishization of the old and the vintage that will come and go.

That is, at least another few years before society collapses and those of us that remain are just looking for some source of water that isn't contaminated by radiation.  They'll laugh at your cries for that pure, vintage tube tone then.


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## Barry (Jan 25, 2022)

Stickman393 said:


> In regards to through-hole components going away:
> 
> I'm skeptical of this train of thought.  After all, tubes haven't gone away as of yet.  BBDs we're getting harder to find, but then Coolaudio and xvive came along and started making new ones.
> 
> ...


I hope you're right!


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## DAJE (Feb 9, 2022)

I recieved 18 (paid for 20) and I've tested a few. Can anyone tell me what numbers I should be looking at here?

Given my luck with pedals lately, I'm assuming they're useless.

EDIT: I compared them to a couple of MMBF5457s I have, and the numbers are way too low. I don't think they're fakes, but I think they're out-of-spec rejects. They only cost a few bucks, so if I can't get a refund it's no big deal, but I would strongly advise against buying from that seller. I have had good results before, but not this time.


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## fig (Feb 9, 2022)

To match, I use the Vgs-off value within .01V of one another.
The datasheet says the tolerance for this value is between -.5 to -6.0.
These are not in-spec ( regarding that value). 

Here is the Datasheet


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## temol (Feb 9, 2022)

Vgs(off) seems to be suspiciously low. I would expect it to be somewhere between -1.2V to - 2V.

ps.  I have some  MMBF5457s from aliexpress with similar, low,  Vgs(off) values and I consider them as fakes. Does not matter - factory reject, fake, rebranded.. way out of spec for 57.


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## DAJE (Feb 9, 2022)

temol said:


> Vgs(off) seems to be suspiciously low. I would expect it to be somewhere between -1.2V to - 2V.
> 
> ps.  I have some  MMBF5457s from aliexpress with similar, low,  Vgs(off) values and I consider them as fakes. Does not matter - factory reject, fake, rebranded.. way out of spec for 57.


Yep, they're not useful for anything pedal related. The two MMBF5457s I have are genuine, not from AliEx, but those are pretty hard to locate these days too. I'm looking out for a good substitute.


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## fig (Feb 9, 2022)

DAJE said:


> Yep, they're not useful for anything pedal related. The two MMBF5457s I have are genuine, not from AliEx, but those are pretty hard to locate these days too. I'm looking out for a good substitute.


Use _could try_ them as clipping diodes.


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## DAJE (Feb 9, 2022)

fig said:


> Use _could try_ them as clipping diodes.


That's an interesting idea. Thanks, Fig.


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## temol (Feb 9, 2022)

MMBF5457 available from Musikding now! https://www.musikding.de/MMBF5457_1


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## spi (Feb 9, 2022)

DAJE said:


> Yep, they're not useful for anything pedal related.


They might work in buffers or top halves of mu-amps.


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## zgrav (Feb 9, 2022)

Very interesting and wide-ranging discussion.  As noted, tubes are still being made and new tech to create other kinds of tubes.  

For that matter, vinyl records outsold CDs in  2021 (admittedly because CD sales have dropped to give way to digital music, but vinyl sales are increasing year to year and that is driving some new turntable and cartridge business).    I thought the efforts to use new tech to improve vinyl playback were interesting (scratch filters, rumble filters, some of the dbx tech that added dynamic range  -- apparently it is very hard to nearly impossible now to find Dolby encoding /decoding chips for cassette tapes  They went out of production years ago.) Maybe some of those concepts will come into play for digital modeling of vinyl playback as well.  The interplay of old tech and new tech still makes some interesting hobby niches along the way.

 Seems likely there is enough NOS on obsolete parts in the world to keep the boutique pedal biz going for a while.


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## finebyfine (Feb 9, 2022)

zgrav said:


> For that matter, vinyl records outsold CDs in 2021



This surprised me so much to read. My parents still buy and use CDs and I would have assumed that there were enough people like them that would have a hard time learning spotify/apple music, let alone setting it up in a stereo/car, etc etc. Mind blowing! And very cool to hear about the vinyl tech.

I’ve tried to be better about keeping up with new/upgraded IC releases for basically the same reason (and I’m a dork who finds it interesting). Ordered a relatively new analog freq divider to see if it can do anywhere near decent suboctaves. Worst case scenario will be fun 

 Last few posts in this thread are making me optimistic again 

Bummer to hear about the jfets @DAJE. Vaxny’s were, until this, my go to for avoiding the 5457 minefield on Ali. :/


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## benny_profane (Feb 9, 2022)

Regarding semiconductors, it's important to consider the trend of consolidation with fabs over the past three or four decades (NB: this is particularly applicable to ICs and not necessarily discrete devices). It used to be commonplace for semiconductor companies to have in-house die fabs to test prototypes and conduct tape-outs. Companies also used to have domestic (CONUS) fabs that could produce at scale. I'm not sure of any company that still has one. Some still have overseas fabs that are company-owned. There have been talks of a new Intel fab going to Ohio and a TI fab in Texas, but those are still years out and a reaction to the current fabrication issues. Niche companies may have their own in-house fabs (e.g., InterFET) or have a business model dedicated to legacy support (e.g., Central Semiconductor), but there has to be a viable market for the parts in order for them to be made at scale and made affordable. These companies have many offerings for analog front end blocks of new products. They have legacy portfolios to supply legacy needs. Central Semi produced Ge devices through the 1980s. This is almost assuredly due to big industrial/military/government customers with legacy equipment. The fact that they make legacy parts doesn't automatically mean that they will be made available for retail customers or wide release.

Companies dedicated to (discrete) analogue parts are rarer and rarer. The general trend in the industry is consolidation. So, companies are acquired and their portfolios are folded into the the purchasing company's IP. This can—and often does—result in (near-)monopolies on certain parts. For parts like the J201 with limited demand and vanishing commercial application, production is de-prioritized for parts with higher demand.

COVID-19 has affected silicon supply chains for myriad reasons, one of which is that there are a handful of giant fabs that handle the silicon for all companies. Another issue is raw material availability. Chip development is iterative. When you have long lead times and increasing demand, it becomes harder and harder to work on your new products. Since those new products are often the ones that are exciting for investment purposes, it's paramount that you be able to get those developed quickly and have some sort of public intro. When that pressure is raised and development cycles are condensed, you have to prioritize what gets produced. Semi companies are prioritizing new development that can establish footholds and contracts in new areas of innovation. This can lead to shortages in other parts if they are de-prioritizing extant portfolio items in favor of new development.

I don't know how appropriate it is to compare discrete JFETs to vinyl. Vinyl is a big part of overall music sales and has a wide customer base. It's been proven that there is a demand for it (so much so that many indie labels/bands are unable to secure spots at pressing facilities). Discrete JFETs don't have an analogous market space. So, while I don't think that we're looking at an extinction of the parts (either in through-hole or surface-mount packages), I think that this particular niche has an outsized need for them while the market demand is too low to really care from a business standpoint.


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## fig (Feb 9, 2022)

Logic prevails. Excellent read.

On that note, I have 100 of of the smd variety inbound from vendor I've used previously. I'll do another "Guess How Many" once measured and matched.


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## spi (Feb 19, 2022)

DAJE said:


> I recieved 18 (paid for 20) and I've tested a few. Can anyone tell me what numbers I should be looking at here?
> 
> Given my luck with pedals lately, I'm assuming they're useless.
> 
> EDIT: I compared them to a couple of MMBF5457s I have, and the numbers are way too low. I don't think they're fakes, but I think they're out-of-spec rejects. They only cost a few bucks, so if I can't get a refund it's no big deal, but I would strongly advise against buying from that seller. I have had good results before, but not this time.


I recently received a few jfets: 4 2n5457s and 4 J201s from GuitarPCB, and 1 2n5458 from Tayda.

To get nerdy with it, I wanted to measure and compare to those bought back in 2013.  I don't have a meter that measures transistors, so I used the technique found at the end of the article here: A closer look at the Fetzer Valve (runoffgroove.com)

I find  the J201s and  2n5458s to be right in the range that ROG measures (the J201s averaged 0.71mA and -0.98V, and the 2n5458 was 4.37mA and -2.62V).

But 2n5457s were out of range, averaging at 1.87mA and -0.43V.   Usually 2n5457s should have Vp around -1.5V.  They are very consistent though, all very close to each other, compared to older batches which had more standard deviation.

I also compared my measuring technique against some old ones, to see if I was consistent with previous measurements and found that it was.

So I'm guessing while manufacturers are still doing some runs of 2n5457s, the don't seem to be using the recipe they used to.


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## fig (Feb 19, 2022)

spi said:


> So I'm guessing while manufacturers are still doing some runs of 2n5457s, the don't seem to be using the recipe they used to.


It's also possible there are NOS-OOS floating about.


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## temol (Feb 19, 2022)

thewintersoldier said:


> If they are of the same quality as the kits they sell that make up 70% of the troubleshooting threads then I would stay as far away from them as possible 😬



I just measured two: -1.4V/2.9mA, -1.5V/3.1mA. I don't see anything suspicious here.


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## temol (Jul 15, 2022)

MMBF5457 available from Musikding now!


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## temol (Oct 23, 2022)

MMBF5457 available from Mouser now!


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## xefned (Oct 23, 2022)

temol said:


> MMBF5457 available from Mouser now!



Strangely, so are the non-surface mount ones. WTF?
Not that that's the subject of this thread. It's just surprising.


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## Kroars (Oct 24, 2022)

temol said:


> MMBF5457 available from Mouser now!


Man!! Put 500 in my cart last night, went to finish up today and they’re gone….  There was 2,000+ last night, figured I’d have a few hours.  Thanks for the heads up nonetheless!!


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## temol (Oct 24, 2022)

Shit happens... But, they're available from Musikding now


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## Robert (Oct 24, 2022)

I have some I've been somewhat hanging on to for prototypes, but realistically I don't think I'll ever use all of these, like ever...

I'll make them available to those who need them soon.


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## benny_profane (Oct 24, 2022)

Robert said:


> I have some I've been somewhat hanging on to for prototypes, but realistically I don't think I'll ever use all of these, like ever...
> 
> I'll make them available to those who need them soon.


Buyer’s remorse setting in so quick?


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## Robert (Oct 24, 2022)

benny_profane said:


> Buyer’s remorse setting in so quick?



Yeah you got me, I was planning to build a new transparent overdrive that uses 2000 JFETs but now I'm having second thoughts....


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## benny_profane (Oct 24, 2022)

Robert said:


> Yeah you got me, I was planning to build a new transparent overdrive that uses 2000 JFETs but now I'm having second thoughts....


Not a Phase 45,000?


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## MichaelW (Oct 30, 2022)

Kroars said:


> Man!! Put 500 in my cart last night, went to finish up today and they’re gone….  There was 2,000+ last night, figured I’d have a few hours.  Thanks for the heads up nonetheless!!


Quest Electronics still has them in stock. 

I bought some not too long ago. These these are the LT1-suffix ones.

Anyone know where I could find some MMBFJ201's? I haven't seen any of those anywhere.


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## Robert (Oct 30, 2022)

MichaelW said:


> Anyone know where I could find some MMBFJ201's? I haven't seen any of those anywhere.



I got some fer ye.


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