SMD Fets

[Flying]

I'm considering a Tweed Man Overdrive, or Covert OD, and I'm planing on using SMD FETs, but was pulled up short when I read in the reviews of the Tweedman OD that MMBF5457's don't work due to the pinouts being different from the 4394, now I was planning on using MMBF4394 anyway as I've just bough some along with some MMBF5458's which share the same data sheet as the MMBF5457. And the pin out for all these SOT23 FETs including the MMBF201 are the same and also say the Drain and Source are interchangeable.

https://www.pedalpcb.com/product/tweedman/

I'm new to FETs, having basically avoided any project with them in as it meant SMD soldering, but I've come to realise that I'm avoiding pedals I really want to try so I'm going to lean how to solder SMD. But I'm confused by the review, so if anyone could shed some light on the pin outs not working I'd be grateful, I feel like I'm missing something simple.

 

[Robert]

I'm considering a Tweed Man Overdrive, or Covert OD, and I'm planing on using SMD FETs, but was pulled up short when I read in the reviews of the Tweedman OD that MMBF5457's don't work due to the pinouts being different from the 4394, now I was planning on using MMBF4394 anyway as I've just bough some along with some MMBF5458's which share the same data sheet as the MMBF5457. And the pin out for all these SOT23 FETs including the MMBF201 are the same and also say the Drain and Source are interchangeable.

https://www.pedalpcb.com/product/tweedman/

I'm new to FETs, having basically avoided any project with them in as it meant SMD soldering, but I've come to realise that I'm avoiding pedals I really want to try so I'm going to lean how to solder SMD. But I'm confused by the review, so if anyone could shed some light on the pin outs not working I'd be grateful, I feel like I'm missing something simple.

Both MMBF5457 and MMBF4393 are the correct pinout and will work.

I should probably remove that review because it is giving misleading information. I talked with the reviewer shortly after he posted that, and although I realize he did have an issue that seemed to be resolved after replacing the transistors, I do not think it was because of pinout / compatibility.

I didn't remove it at the time because I couldn't confirm nor deny the accuracy, but since then both of those parts have been used successfully.

 

[Flying]

Thanks PedalPCB, the review under it also says the MMBF4393s are discontinued, I'm assuming that's a typo and it's the MPF4393 that's discontinued. It almost had me panic bulk buying ;-)

And I slipped up as it's not 4394 it's the 4393 I meant! It's been a long week, that's my excuse!

 

[Robert]

Haha I did the same thing. Yes, MMBF4393 is what I meant.