Xpander VCF

[Haible Juergen]

	>in some modes, one stage is bypassed. That stage will be unstable
	>without ANY cap at all, so it is disabled by using a cap that is
way too 
	>small (that pole tuned all the way up...)

Yes, that's an important point ! 
It's like an externally compensated opamp which must be stable over
decades of varying bias current of its input stage.

But ... isn't there a problem with resonance then ? Self
oscillation should occur later (more gain) in these "bypassed modes".
Is this compensated for in the XPander ?

JH.