I must have posted the wrong link... Here's the right one and a few more :

1. Very old Fender Mexico Strat ---> Dual Mice ---> Marshall Plexi
(first with cut switch on - Ruetz mod, and then with cut switch off)

http://www.box.net/shared/ruo4ttdxgh

2. Hamer Californian ---> Dual Mice ---> Guitar Rig 3 Twin Reverb Simulation  xD

http://www.box.net/shared/8rrmbql0xi

3. Hamer Californian ---> Vintage Rodent (another Rat clone I built) ---> BrandX X-15R 

http://www.box.net/shared/15nqbkffs8
http://www.box.net/shared/gvbsu4fbrd
http://www.box.net/shared/ta5bt7xuv3
http://www.box.net/shared/65ppumpf0y

More samples soon... 

Thank you for all the advices and help! 

And a sound sample:
http://www.box.net/shared/q1baxvm44t

Just replaced the output transistor and and it works fine now  The problem with the voltages was in the multimeter with very low internal resistance... 

Quote from: J M Fahey on September 20, 2009, 11:43:59 PM
Pins 2 and 3 should match within millivolts, or less.
Simpl circuit=few possibilities: mistake on PCB, bad chip, solder bridge, etc.
Change the chip first and take a good close look with loupe or good glasses.
Scratch between pins that are close but shouldn't be interconnected.
Worst case: build another.
Good luck.

I took the IC out and measured the voltage on the pin 3 socket, it's the same. Pins 7 and 8 aren't directly connected in any way. Maybe a bad IC?

I just finished building my 3rd ProCo Rat replica today. There are 2 problems:

1. The output volume is very low, half the volume of the bypass signal with the knob turned all the way up.
2. Sound is very fuzzy and compressed even on the lower gain settings.

Here's the voltage chart:

IC1:

P1: 8.32V
P2: 4.19V
P3: 2.04V
P4: 0
P5: 0
P6: 4.20V
P7: 8.42V
P8: 8.32V

..and schematic:
http://www.generalguitargadgets.com/pdf/ggg_rodent_sc.pdf

Compared with my other Rat clones all voltages are ok except the P3 and P8, they should be somewhere around 4.5 volts.

Any ideas?