Hi Guys, I'm trying to amplify a millivolt signal from an electrode that has a high input resistance (~ 200 MOhm). To avoid losses over the series resistance i'm using a high input impedance Op Amp TL071CP as a voltage follower. The problem i'm having though is that for some reason when the op amp is powered with +-12V (or any +- votlage for that matter) I am getting -10.2V at the non-inverting input and consequently seeing that voltage at the output, even when the probe is disconnected. Ideally I would have 0V at the output when nothing is connected. Does anyone have any suggestions as to why this may be happening?! It's been bugging me for hours. Cheers.