Cyclegadet,
I suggest you take a look at the Analog Devices and TI web sites. Both offer a wealth of information re: op-amps and from the looks of it, your application is tailor-made for an op-amp. You could go for a G=1.5 circuit that simply shifts the signal from +/- 0.7Vrms to 1.5VDC +/- 1.5Vpp. That would result in a signal from 0-3VDC, well within the specs of the Due ADC. Plus, you gain the benefit of a low-impedance source, i.e. one that will make the ADC inside the Due very very happy.