New Stuff

[Haible Juergen]

	>Yes it's great simple VCA. I like it alot.

And it even has a built-in balanced output. Just bring out the left leg of
the final
differential stage as well.

	>I've redrawn them as in original papers, just substituted opamps 
	>and semis with more available ones, 

This is what I mean. Substituting opamps will most probably change the
bahaviour
of the circuit. In the EML filter, there is a 3.3pF capacitor across one
100k feedback
resistor. This will normally do some compensation on the frequency response
of Q: The delay introduced by the opamps would make Q vary with cutoff
frequency.
Now the point is that the manufacturer has compensated for one specific
opamp
(whichever that might have been), and if you do an "upgrade" with a faster
opamp,
you might have some over-compensation.
Just an example - don't know how much it matters in that circuit (probably
not
much). But that's why I was asking.


	>no other changes (except obvious
	>errors), so people can build them easily. I also provided all
original
	>notes found in schems, and listed all original opamps/semis so it
	>can be useful for repairing original modules.

Yes, that's excellent. I should have looked more closely before I've
answered.

JH.