[sdiy] Help deducing the internal resistor values of the IR3109?

[Jack Jackson]

I've been looking at the schematic of the IR3109 freely available on the web. It is just four OTAs, four buffers and an expo converter apparently. The main missing piece of knowledge is the values of the internal resistors between the gain cells non-inverting inputs and ground:

http://flic.kr/p/goAsc3

The schematic also has a bit of useful information:

http://flic.kr/p/goABBB

I have 2 of these chips to hand. Can anyone think of a way to deduce the value of the resistors by taking measurements externally etc?

Thanks,
Jack