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Two questions (that I also asked in another build report): 1. Do you notice a volume change when you turn the MIX knob from Dry to Wet? 2. How did you go about setting the two trimmers?

“When a clown moves into a palace he doesn’t become a king, the palace instead becomes a circus." Turkish proverb shared by Dan Rather

I wonder what Mike Fuller's thoughts are on this?

Good catch! Vero corrected.

My final version. Yes, it really needs all 6 knobs. It's basically two ODs connected in series with the EQ in the middle. The GAIN & DRIVE stages can each be dialed-down to unity gain for (mostly) clean boost and EQ. Or run both stages at low gain (below noon) for some smooth OD. The MID...

Yes, there is a bootstrap in there too. C10 bootstraps R7, making it appear to be orders of magnitude larger than 100K.

It's all about getting the JFET biasing right. JFET circuits are not plug-n-play. Plan on selecting R4 & R12. Stock values might work, but there is no guarantee. We're looking for around 5V on Q1-D. If it's higher than 5.5V or lower than 4.5V, then adjust R4. Increasing R4 makes Q1-D go up...

That's normal. Really no way around the popping in this circuit.

Do you not read my responses?

Buy extras, you will need to screen them. If you buy 5, maybe they will all work in this circuit, maybe only three will.

Thanks for that! As expected, Bias centers the sweep. Turning DEPTH all the way up can get a bit extreme. Higher Vp produces a wider sweep, once Bias is dialed-in.

2N5089 is a BJT, not a JFET. It is still in production, but pricey at DigiKey & Mouser. Equivalents include BC549C & MPSA18. The pinout is reversed with BC549C. For the JFET, J113 is a good sub and is in production. Might as well buy at least 10 because they show up in a lot of pedals. As...

Testing that way is equivalent to the in-circuit test I described above. The only difference is meter polarity. If you want the true polarity, then connect the DMM + lead to GND (gate) and - lead to source. The drain and gate resistors don't impact the measurement because the the test...

Look at post #2. We're looking for Vp close to -0.2V. Your J201s are compliant with the J201 spec, but they are not suitable for this circuit.

You probably got lucky. You can measure Vp in-circuit if you lift one lead on R5 & one lead on R7. Power up and connect you DMM from Q1-S to GND. The voltage you read is essentially Vp. Then measure from Q2-S to GND.

I had not thought about it until now. The diode current is less than 200μA, so it's hard to gauge the LED's Vf from the datasheets. LED leakage and capacitance vary quite a bit so you might end up selecting LEDs or at least qualifying lots. 1N4148s are very consistent. Try it and let us know...

Ever think of looking at part 2?

Same process as N-channel JFETs, just reverse the polarities, i.e. drain voltage is negative. I should mention that my CCTT cannot test P-channel JFETs.

Sure, why not. If you don't mind the inversion. I thought about it and the parts count is about the same. TLC2272 would be a good choice. You'll probably ditch the red LEDs too 😜