# 2n5457 Replacement



## Billyhank (Sep 13, 2021)

What would be a good substitute for a 2N5457 in a Bluesbreaker circuit?

 I’ve included the schematic if that’ll help.


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## Billyhank (Sep 13, 2021)

Awesome!!! Thank you!


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## temol (Sep 14, 2021)

Try to source SMD versions of the transistors. 

btw - depending on a circuit, J201 may not be the best replacement for the 2N5457. Here, it should be ok.


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## jeffwhitfield (Sep 14, 2021)

AionFX has 2N5457 chips for a reasonable price. They basically took the surface mount version and adapted them with a little PCB. Works well and gives you the same as a standard through hole version









						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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## bowanderror (Sep 14, 2021)

I'd 100% recommend the SMD adapter board route. There is much less risk of getting counterfeit parts (a big problem), and the Vp & Idss specs are much more consistent. I had 100 of these SMD adapter boards made at JLC PCB for less than $10. It has sides for DSG and SGD pinout, but none of my SMD JFETs have been the correct pinout for the SGD side. The DSG side works great though, and has the pinout labelled on the silkscreen. If you go to "Action" -> "Download", you can download the Gerbers and order them from your fab house of choice.

The boards + transistors will run you quite a bit cheaper than through-hole JFETs, especially if you buy a bunch:

~$1/each for less than 10
~$0.50/each for 10-100
~$0.30/each for 100+

You can get SMD 2N5457s (MMBF5457) at Digikey, Tayda (currently out of stock) and even Amazon (I've purchased these & they tested fine, but YMMV)

You can get SMD J201s (MMBFJ201) at Digikey, Smallbear, Tayda, and AES


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## Billyhank (Sep 14, 2021)

bowanderror said:


> I'd 100% recommend the SMD adapter board route. There is much less risk of getting counterfeit parts (a big problem), and the Vp & Idss specs are much more consistent. I had 100 of these SMD adapter boards made at JLC PCB for less than $10. It has sides for DSG and SGD pinout, but none of my SMD JFETs have been the correct pinout for the SGD side. The DSG side works great though, and has the pinout labelled on the silkscreen. If you go to "Action" -> "Download", you can download the Gerbers and order them from your fab house of choice.
> 
> The boards + transistors will run you quite a bit cheaper than through-hole JFETs, especially if you buy a bunch:
> 
> ...


I’ve got one coming from a member here, totally offered up to send me one. Lol. I was just impatient and wanted to finish the build with something that would work. 
I was planning on keeping an eye out for some 5457s or the smd boards.


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## bowanderror (Sep 14, 2021)

Nice! I was nervous to solder these at first, but it was actually super simple. The key is to secure the adapter board in place in a piece of blue tack and pre-cut 1-2mm lengths of solder to place near the pad. That way you can hold the tiny SMD part in place with tweezers and melt the solder onto one of the pins. It will be pinned in place after that and you can solder the other pins no problem.


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## Billyhank (Sep 14, 2021)

bowanderror said:


> Nice! I was nervous to solder these at first, but it was actually super simple. The key is to secure the adapter board in place in a piece of blue tack and pre-cut 1-2mm lengths of solder to place near the pad. That way you can hold the tiny SMD part in place with tweezers and melt the solder onto one of the pins. It will be pinned in place after that and you can solder the other pins no problem.


I’m a little nervous about them too. Lol. I’ve never worked with something that small.


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