Chasm Reverb Hiss Noise

[andrea83]

Hi everyone!
Some months ago I built the Chasm with the PCB from Rob (Dead Astronaut) for my wife which is a drone music guitarist
The pedal is great, but it has hiss/noise when the mix and the level are turned all the way up and this noise comes out even when the effect is bypassed so in chain with other effects it becomes very annoying..

I checked everything at least 100 times.. changed the tl072 and swapped the 2n7000 for a bs170 (with the right pinout), I also changed the 33R to jumper in order to avoid the voltage drop.
Reading the voltages from MAO ( http://guitar-fx-layouts.42897.x6.nabble.com/DeadAstronaut-s-Chasm-Reverb-td30063.html ) I can find mine different, especially in the MOSFET.

here are my voltages:

78l05
I 9.10
O 4.98
G 0.00

TL072 (IC1)
1. 4.33
2. 4.33
3. 2.15
4. 0
5. 4.53
6. 4.58 (not steady)
7. 4. 62 (not steady)
8. 9.10

TL072 (IC2)
1. 4.58 (not steady)
2. 4.54
3. 4.54
4. 0
5. 4.54
6. 4.58 (not steady)
7. 4.58 (not steady)
8. 9.10

2n5457 (both)
D. 4.33
S. 4.33 (once I see that decreasing)
G. 0 

BS170
D. 9.10
G. 4.30
S. 2.38

Any ideas? I see that it's a problem shared by some people, a guy told to make it true bypass to solve it, but the unbuffered output look much lower than the buffered ones.
THANKS!