Weird Parts needed - Stone Grey Dist

[motterpaul]

I see what you are saying.



But because he mentioned the weird pinout of the 2n3819 in the introduction I didn't really check the labeling in the layout - but if I had noticed I would have assumed that he just mislabeled the tranny in the layout;  I also read notes from other people that said that you need to twist the pins if you want to use other FETS than the 2n3819. I assumed that was why the 2n7000 has a different layout.

Anyway, it  is a moot point now, I also built an LED version of this and no matter what I do I can't seem to tame this circuit. Just so bright it is ridiculous. It makes a decent treble boost with the gain off, though.

I only wondered about JHF comments about the voltage going to the 3069 - he says it has a big effect on the tone quality. I wonder if anyone has experimented with that.

[Travis]

If you are getting enough low end, but there is too much treble, you could fix this with a simple low pass filter.

If you're not getting enough low end, keep increasing the value of the coupling caps and the added bass will reduce the perceived amount of treble

[motterpaul]

Travis. you mentioned the 2n2. I socketed it and tried a number of different caps, going up to 47n and down to 810p for example. Did not help. Then I looked at the tone 22n with a 50k pot, which seems to be a high pass filter (cap followed by resistor), and I tried a number of different caps in there and nothing changed. It seems that because it is a HPF lowering the corner frequency didn't add bass, it just seems to make it get less bright, but even with the tone full CCW it is too bright with any cap.

There is probably something else I am missing - but I don't know what else to try.

Thanks for input.

[Travis]

Check out the 10n next. Try increasing that along with the input cap. 100n is a pretty common value for coupling caps where you usually don't lose low end with a guitar. Many distortion designs trim low end to avoid "muddy" distortion. A lot of this depends on the guitar and amp used

[induction]

motterpaul wrote

... I looked at the tone 22n with a 50k pot, which seems to be a high pass filter (cap followed by resistor), and I tried a number of different caps in there and nothing changed. It seems that because it is a HPF lowering the corner frequency didn't add bass, it just seems to make it get less bright, but even with the tone full CCW it is too bright with any cap.

It's a cut-only high-shelf filter, just like a guitar tone knob. It bleeds treble to ground and leaves bass in the signal. Increasing either the cap value or the pot value will give more treble roll-off at full CCW, but should leave the EQ unaffected at full CW. Try a 100k pot or a 100n cap, if you haven't already. Go higher if necessary.

Because it's a shelving filter it reduces the high frequencies by a specific amount. At full CCW with high RC values, it will start to reduce bass as well. I low-pass filter would work better because it would reduce treble in proportion to frequency above the corner. So higher frequencies would be reduced even more.

None of these things will increase bass response though. And if the output is too shrill (rather than just too bright) then you might be better off cutting treble on the input side rather than the output side. Try turning down the tone knob on your guitar and see if that gets you closer to what you want. If so, you could put a low-pass filter on the circuit input to make it permanent.

[motterpaul]

Thanks for the input. What I do need is more bass (and I have the tone at full CCW, so I also need less treble).