Quote Originally Posted by Ioannis
I have a heavy analog project that requires at least 70 analog values (from pots) to be converted
I would be inclined to use a CMOS multiplexer such as a 4051

Use one of these for every 8 pots. Inputs ABC give binary selection of the pot to be sampled. There is also an inhibit pin that disables all switches so can be used as a chip select.

For 70 pots, 9 of these would give you 72 inputs. You could use multiple A/D inputs to sample more than one bank at a time, or just a single A/D input by commoning all the 4051's together.

digital requirements would be ABC + 1 inhibit pin per chip so a total of 12 lines but even that could be reduced by using something like a couple of 74HCT595 to drive the multiplexer chips using just 3 lines.