Seventheaven: Clarifications and doubts

[Lobbetto]

Sorry to trouble, but I would like to ask you which of the two schemes are exact to build this pedal for guitar.
One is designed by Mark, the other edited by Johnk.




They are similar, but have differences in Cap 100n values in the layout of Jöhnk.
And the arrangement of components change in the path that leads to Q4 to Q5, and also two 100uf instead of 220uF.
Finally which of the two charge pumps works best.

I am about to begin the Mark layout, but I'd like to know which is correct and verified.

Thank you, I hope you can answer me as soon as possible.

[Beaker]

I have not built either layout, so don't know for sure, but both layouts are essentially the same, just arranged slightly differently as far as I can see.

John uses two 100uF caps in parallel (giving 200uF) while Mark uses one 220uF cap on his layout.

Both layouts are verified, so either one should work. Any differences should have little or no noticeable effect on the sound.

[Sensei Tim]

I have built the second one and it works

[Lobbetto]

Well, I'll start the layout of Mark then. Socket Cap that the Johnk changed if I would use its modification.
Thanks for the answers!
I decided to build this, because I built BlackForest by JOK3RX but I had no luck, the J201 does not produce distortion, and 2N5457 squeels.
Tried to mix transistors and squeel disappears, but the gain decreased a lot, so I disassembled components and I will make with BF5 PCB.

Thanks again.

[induction]

If you don't mind a recommendation: get a breadboard. Life's too short to spend your time and money building pedals that don't work or that you just don't like. You'll never have to wonder whether your jfets bias properly, or if you should have swapped input caps, or put this or that component on a switch. When you troubleshoot and optimize the circuit before your break out the soldering iron, you don't just save time and money, you also end up with a better pedal.

[Lobbetto]

The breadboard, will certainly be my next purchase, you're absolutely right. So I should first work on the prototype before moving to a permanent achievement, but I honestly thought that being verified layout, I should not have problems, I thought enough an audio probe to find the some problem.

I would add that I posted a request for creating the layout for the divided by 13 FTR 37.
If someone succeeds, I'd be curious to try it.

[induction]

Lobbetto wrote

The breadboard, will certainly be my next purchase, you're absolutely right. So I should first work on the prototype before moving to a permanent achievement, but I honestly thought that being verified layout, I should not have problems, I thought enough an audio probe to find the some problem.

I never build anything I haven't breaboarded first, and I have breadboarded many circuits that I decided not to build, but that's me. It's actually very satisfying because you get to try out the circuit in far less time than it takes to build it. Sometimes you just want to taste it, and then you realize you don't like it enough to build it, or maybe you'd like it better if it had more or less of this or that.

Verified layouts are fairly safe with many circuits, but the risk of a circuit not working or not sounding right increase dramatically when there are jfets involved. The tolerance for jfets is huge, and they often have to be hand-selected to fit the biasing. Very often you can alter the biasing resistors to get them to work, but in many cases that will drastically alter the sound of the circuit. All of these considerations are far easier to handle on the breadboard than they are on a soldered vero or pcb.

With jfet (and bjt) builds, I use the exact same components for the final build that I used on the breadboard. Op-amps aren't nearly as finicky, so I'll often leave the circuit on the breadboard while I populate the build with 'identical' components.

It's very easy to think of all components with the same part number as identical, but with jfets that's not even remotely true.

[Travis]

+1 on the breadboard. I do the same as induction, breadboard almost every circuit before soldering, and use key components (transistors, JFETs, etc) from the breadboard in the final build