This Week on the Breadboard: The Nut Job OD

[YourGuitarist]

We have

What the heck, was looking for an excuse to test drive KiCad 10!

(Still not sure if I like it. DRC and zone fills are so much slower. And it's back to doing the thing where it crashes if you run DRC after making too many changes)


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Jfets at home...

 

[Chuck D. Bones]

J210's work also, just had to pick the right ones and tweak the source resistors a little bit.

Note: not a typo. I used three J210 JFETs. The ones I measured have Vp around -2.1V to -2.5V & Idss between 2.3mA to 5.7mA. Similar to 2N5484 & 2N5952.

 

[anevilspar7an]

Unfortunately I can't find J210 anywhere that isn't ebay or Digikey for under $5 a piece.

 

[Chuck D. Bones]

There are plenty of JFETs that will work.

 

[music6000]

One more update...
I recently picked up some J2902 JFETs (no datasheet) for a good price and was looking for an application. I measured a few and they are similar to the 2SK30A-Y (different pinout). Lots of other JFETs will work, we just have to fiddle the biasing and gain on each stage.

View attachment 125206

Q1 is lower right, Q2 is up and to the left, Q3 is far left. A couple of spare JFETs bottom center.
Knobs(L-R): LEVEL - BASS - MID - TREBLE - GAIN

I give you a Nut Job: