Sabbra Caddabra JFETs?...

[Coda]

Working on a Sabbra Caddabra. Does anyone know what I should be looking for, Idss/VP-wise?...

 

[Coda]

Ok, to kind of answer my own question: it seems that any JFET within the “standard” spec (for pedals) will work. However, that doesn’t mean it will sound good. I’ve spent the morning popping in all sorts of different JFETs, and they all sound different. I’ve zeroed in on some SK193. I’ve also have a 5089 at Q1. Of course, it’s not 100%…it sounds a bit gated on the attack. But I suppose that’s another thread…

 

[spi]

2 of the gain stages are mu-amps. I've heard that the specs of the lower transistor is much more important than the upper one for the sound.
Check the data sheets of the 4393 for their ISS/VP and put the ones you have which are closest in the lower positions. You can be less picky about the others. I did that when I built a BSIAB and it worked out good.

Also, I think Aion sells those transistors.

 

[Coda]

I think I have the muamps (Q2,3,4, and 5) figured out well. I am getting signal no problem, it’s just gated on the attack. The pedal sounds more fuzz than anything. With the Range control down I can almost get an octave effect…

 

[jwyles90]

I’m sure you know about this already, but Aion Fx sells matched sets of the MPF4393 fets. That might not answer your question specifically, but I used those when making that build and they sound freakin killer

 

[Coda]

I’m sure you know about this already, but Aion Fx sells matched sets of the MPF4393 fets. That might not answer your question specifically, but I used those when making that build and they sound freakin killer

I ended up using PN4393 (and one 2n5246 for Q6, since I ran out of PN4393's). I don't really think it matters which JFET's you use, as long as they are in spec...

 

[Coda]

I ended up using PN4393 (and one 2n5246 for Q6, since I ran out of PN4393's). I don't really think it matters which JFET's you use, as long as they are in spec...

Actually, the one real change was Q1. With the Bc183 that the BOM calls for, I wasn’t getting what I should have, gain-wise. The 2N5089 that I ended up with does the job nicely…