question about making a big muff with an jfet based input and output stage

[jubal81]

There was a contest recently for alternatives to build on a muff PCB and I did JFETs all around. Came out great.
https://forum.pedalpcb.com/threads/what-another-contest.10105/page-9

[snow123]

Q1 (J201):
D: 2.75
S: 0.00
G: 0.47

Are you sure about Q1 as J201 n-channel JFET..??

yes? i'm using SMD j201s that i soldered onto a through hole adapter board

[antonis]

There was a contest recently for alternatives to build on a muff PCB and I did JFETs all around. Came out great.
https://forum.pedalpcb.com/threads/what-another-contest.10105/page-9

I'm not sure if snow123 would approve the above JFET "anorthodox" (according to his own standards) bias configurations..

[snow123]

There was a contest recently for alternatives to build on a muff PCB and I did JFETs all around. Came out great.
https://forum.pedalpcb.com/threads/what-another-contest.10105/page-9

I'm not sure if snow123 would approve the above JFET "anorthodox" (according to his own standards) bias configurations..

tbh i just dialed it in to where it sounded best, and didn't measure until afterwards.

[PRR]

There was a contest recently for alternatives to build on a muff PCB and I did JFETs all around.
https://i.postimg.cc/tsDrzvSQ/Fuzzduster-SCH.png

As I see that drawing: Q2 Gate has no DC path. If it works it depends on PCB leakage, which is unreliable.

[antonis]

As I see that drawing: Q2 Gate has no DC path.

At a first glance, I saw the same thing, Paul..

But it actually does have via R7, C4 short, Sustain wiper and R6..

[duck_arse]

As I see that drawing: Q2 Gate has no DC path.

At a first glance, I saw the same thing, Paul..

But it actually does have via R7, C4 short, Sustain wiper and R6..

me counts three.

[antonis]

So, does that make us a crowd..??

P.S.
Finally, snow123 threads DO have "juice"..

[jubal81]

There was a contest recently for alternatives to build on a muff PCB and I did JFETs all around. Came out great.
https://forum.pedalpcb.com/threads/what-another-contest.10105/page-9

I'm not sure if snow123 would approve the above JFET "anorthodox" (according to his own standards) bias configurations..

If it looks weird, it's drawn to be built on a PedalPCB Muff PCB. C4 is a jumper. The treble bypass on the gain control and Q1 bypass cap have to be added extra to the PCB, the orphaned resistors are left empty and the numbering matches the PCB exactly.

[snow123]

also, using J201s for Q2 and Q3 makes it clean up almost like a fuzz face.

To make the J201s work, I connected the sources of Q2 and Q3 to ground, used 5.1k for R10 and R16, and I lowered R7 and R12 to 2.2k to boost the gain a bit.

[antonis]

To make the J201s work, I connected the sources of Q2 and Q3 to ground, used 5.1k for R10 and R16, and I lowered R7 and R12 to 2.2k to boost the gain a bit.

May I notice that the above aren't in compliance with any schematic posted by you (till now, at least..)..??

[Phend]

What will this new J Muff be called ?

[snow123]

What will this new J Muff be called ?

idk, JFET muff? im bad with naming things lol

[snow123]

To make the J201s work, I connected the sources of Q2 and Q3 to ground, used 5.1k for R10 and R16, and I lowered R7 and R12 to 2.2k to boost the gain a bit.

May I notice that the above aren't in compliance with any schematic posted by you (till now, at least..)..??

the names are in compliance with the last schem i posted (reply #55), but the values aren't.

[duck_arse]

I retract my previous comment, about "finished".

[amptramp]

What will this new J Muff be called ?

idk, JFET muff? im bad with naming things lol

Pinchoff Muff would keep everybody guessing.

[anotherjim]

Mufa Fett.