This modification isn’t any more complex than the core volt-mod. You should solder a 10,000Ohm variable resistor to the resistor marked in the picture (R34):
Or draw over that resistor with a lead pencil.
The voltage is monitored on the legs of this capacitor:
Warning! If you are guided by the recommendations fromvr-zone.com, make sure you’re using their monitoring points – they are different from ours!
On my card, the original memory voltage was 1.81V. I increased it to 2.0V (by reducing the R34 resistance from 625Ohms to 540Ohms; in other words, a 0.1V voltage increase is achieved by reducing the mentioned resistance by about 40Ohms) and reached a memory frequency of 855MHz. This is comparable to the best results of other versions of the GeForce 7600 GT where the memory voltage is initially set at 2.0V.
I also think that the memory chip on Palit GeForce 7600 GT Sonic cards can be overclocked to even higher frequencies. I increased the voltage to the value the chips are rated to work at, but it would be quite safe to lift it up to 2.2V (I just had too little time to modify and test the graphics card).
This is what the modified section of the card looks like: