Hey breaktru, I must have some finiky carto's or juice that likes the lower voltage because I get some great flavor from them at 2.9-3.1v, but anyway I only used the 1k pot because i'm still waiting for my jameco order to arive. I have 2 200ohm pots in that order thats taking forever to get here. I also have a 220 ohm resistor on my pot. I guess I was just in a hurry to get this up and running so I used an old pot from a psu I had laying around. But you say the lowest you can go is 3.4v...hmmmm I guess I will have to try and push these carto's at 3.4 for a few days to see how they perform before thursday when my order is supposed to arive. I would really love to see your copper mod, I have read your posts about the digital pot and the nightmare soldering task that they pose, Have you found a socket for it ?