Octature osc?

[Martin Czech]

> http://www.tomg.vivid.net/misc/q_osc.gif
> 
Does anybody understand, what the switch in above schematic is
for? I see the double integrator of an state var, but what does the
switch? The 5k pots regulate frequ, but amplitude ?
Why should the switch connect the leftmost op amp to some lonely
pot and otherwise leave the next integrator with no input current?

m.c.