Box of rock clone, volume problem

[ricci]

The bottom pin of R16 may not be connected to GND
or there's a bad GND wire on the part. For example, R13 R16 have no connection to GND

The ground connections are solid.
thx

[ricci]

I have tested the connections many times and the continuity has always been there. I also replaced the mosfets even though when I tested them in diode mode they appeared intact but nothing changed. I do not know what to do. Tolerances don't really matter, there are no critical components and I redid the PCB in four different ways, but always the same volume drop problem. Maybe the people who say they made it didn't have the opportunity to A/B test, otherwise I'm sure they would have noticed, like in this video. But why !

at 8:44

[Helmholtz]

A missing ground connection would not cause permanent DCV on the pot.
If there's still DCV on the pot, find out why.
I think the DCV must come from the drain of the third Mosfet.

[x-pro]

A missing ground connection would not cause permanent DCV on the pot.

I apologize, I didn't follow through.
R16 terminals may have been erroneously connected to +

[x-pro]

ricci, Enjoy Your Sound! Guitarists hunting for their sound.

[ricci]

I apologize, I didn't follow through.
R16 terminals may have been erroneously connected to +

No

[Helmholtz]

What's the DCV measured between the ends of C6?

[ricci]

What's the DCV measured between the ends of C6?

2.0V

Side + 4.678V
Side - 2.68 V

but is unstable

[ricci]

Now the voltages on the tone are different:

T1 2.30v
T2 0.29v
T3 0.25V

[Helmholtz]

Your measurements don't look consistent.
What is T1/2/3?
Is your meter battery fresh?

Does the DCV at the tone pot disappear when you lift one end of C6?
Do you still get sound with one end of C6 lifted?

[ricci]

T1 is the lug1 of the tone pot etc..2 and 3.

Yes, I use a stabilized power supply

[ricci]

Your measurements don't look consistent.
What is T1/2/3?
Is your meter battery fresh?

Does the DCV at the tone pot disappear when you lift one end of C6?
Do you still get sound with one end of C6 lifted?

Yes, if I disconnect the side - of C6 I still hear the sound but with a very low volume and the voltages are:

The voltages are about:

Lug1 0.7v
Lug2 0.09v
Lug3 0.13v

and they remain almost constant with both one leg and two legs

[x-pro]

is the board cleaned of flux? they can be conductive

[x-pro]

Now the voltages on the tone are different:

T1 2.30v
T2 0.29v
T3 0.25V

Maybe the author has pin 3 of the LEVEL regulator connected to +9V instead of GND?
But then it is not clear why these voltages drop when C6 is turned off ?
Something is wrong with the mounting or tracing of the PCB.

[ricci]

With the premise that the controls of my clone are at maximum, a few days ago I had observed that the two pedals sounded identical only when I kept the volume of the performance clone at 3 o'clock and Gain and Volume at maximum, now I noticed the same with the tone potentiometer of the clone performing, that is, if gain and volume are at maximum and the tone at 3 o'clock, the two pedals sound the same but if I go beyond 3 o'clock the sound becomes increasingly more devastating.