AW: [Switchable ladder filter]

[Haible Juergen]

	>>Dave: Some simulations I did indicate that you might be able to do
just
	>>that... but watch out for your supply voltages. As you add stages
you need
	>>more voltage to support it. I went to 5 stages without problems. 
	>
	>The Minimoog use 10 volts (for four stages), so 15 volts must be
enough for six stages.
	>
	>/Jorgen

I'd say 1V per stage would be more than enough. For linear operation I'd
expect it to work
with as low as 300mV per stage (the CE voltage can be smaller than the BE
voltage). For
overdriving the filter, you might add a little reserve. (But this is *not*
tested nor simulated.)

JH.