MOSFET amp emulator and MOSFET Mu Amp

[amptramp]

This has come up again in this thread:

http://www.diystompboxes.com/smfforum/index.php?topic=118011.0

and I have posted a slightly better explanation of the difference between a µ-amp and a constant current load stage.  It seems interest in these two circuits is continuing.

[POTL]

This has come up again in this thread:

http://www.diystompboxes.com/smfforum/index.php?topic=118011.0

and I have posted a slightly better explanation of the difference between a µ-amp and a constant current load stage.  It seems interest in these two circuits is continuing.

I think this is due to many factors
1) distortion pedals on FETs sound much more interesting than classical effects using operational amplifiers
2) In principle, now almost all manufacturers produce basically a "standard soup set" Screamer, Rat, Ocd, Muff - it's jaded and terribly boring.
For users and new builders, these effects are no longer so interesting, since now they are at every step for every home master =)
Regarding the topic, yet the differences, albeit small in the matter of this user and mine, are
He asks about the schemes on JFET, and I'm talking about MOSFET
Schemes on the JFET, I studied the length and breadth and collected many samples, but now I can not get MOSFET to work correctly = (

[reddesert]

In your circuit - 3rd schematic in reply#18, with R2 removed - you can see that there is a direct path from +9V to ground through the two MOSFETs. That is, 9V to source to drain to source to drain to ground. If both MOSFETs are conducting, and there is no R2, then you're dumping voltage through them with no R2 resistor to limit the current. That's why it's getting hot.

I understand that you got this circuit by adapting the 1st schematic where Q3 and Q4 are JFETs wired similarly between +9V and ground. But JFETs and MOSFETs are biased differently, and so it's possible that in the JFET circuit one JFET is acting like a drain or source resistor for the other, but this is not working for the MOSFETs.

[POTL]

Thanks, it turns out that even setting the resistor 2 in place will not fix the problem.
You can tell how to properly simulate this cascade using MOSFET
This is a classic amplifying cascade in British amplifiers

On JFETs its look like this

How to do this on MOSFETs

[POTL]

It seems I figured out how to do it.
In fact, you just need to add resistors rated at 1 mеgo ohm for biasing gate

[POTL]

In general, if anyone is interested, I built and started this pedal
It works fine, but no more, Saturation is more, but it's too much, the sound is too colored (to someone it's a plus, to somebody's minus), a lot of clang (this is typical for MOSFET), it's a little bother, especially at high frequencies, or They are cut and clanking is acceptable but the sound is deaf or the sound is bright, but the clang is too much, the balance is hard to find.
In general, the sound is like Box Of Rock.
In the drain, I used the trim, in the source resistors from the amplifier circuit.
Perhaps the result would be better if I used smaller values ​​at the source, as is done in Box Of Rock.
For myself, I concluded that JFET is still better, Sound balanced, more natural, not colored
At least it became clear why almost all manufacturers use JFET and not MOSFET.
Thanks to everyone who replied

[POTL]

musfet mu amp

[amptramp]

^^^

The output should come from the source of the upper stage, not the drain of the lower stage.