Flipguitarist
Member
I’m trying to build this pedal and I’d like to ask before I solder the components if it’s ok to use jfet 201’s in place of mpf4393’s on q2-q6 and a 2n2222 on q1? Thanks.
I have two boards ordered the correct parts so while waiting I’m gonna build one with the mentioned replacements. Would they work? Thanks again.you could use sockets to preserve some options on transistors and give it a go.
Thanks a lot once again! Will update once complete.The JFET gain stages are mu-followers and are pretty forgiving of FET types because the bias point is set by the resistor string connected to the gate of the upper FET and NOT by Vp. Most N-channel JFETs will work. That being said, MPF4393s are easily obtained in the US. Try Electronic Goldmine. They sell a pack of 5 for $5. That's where I get mine. Any high-gain, low-noise Si transistor will work for Q1. We'd be hard-pressed to hear the difference between BC184, BC550 and 2N5089. I would not use 2N2222 because it is not a low-noise transistor.
Oooohhh I don’t know how. I can try though. Link me where to get them? Thanks.Theres definitely something special about 4393s in catalinbread circuits! The SMD versions are still plentiful if you’re ok soldering those tiny things.
Electronic Goldmine is not showing any MPF4393s in stock right now, but that no doubt changes over time.
https://shop.pedalparts.co.uk/PN4393_N-Channel_JFET/p847124_17055653.aspx Fuzzdog has some PN4393s as well if you dont want to bother haha. But if you want to try just search for MMBF4393 at mouser or DigiKey etc, you’ll need an Adapter board too but pedalpcb has those.
So how did you go about installing them through hole without an adapter?Oh yeah those little buggers are last resort material haha. I’ve had to do it for 5457s because I’m not paying 5 bucks a pop or whatever it is for proper working ones.