AW: Climbing the Moog ladder

[Haible Juergen]

	> I might
	> try the suggested SSM parts, but I do like the sound of this
filter.

I shouldn't talk to you anymore, after this statement, no ! (;->)
Well, never mind, each one has his own's preferences.

	>Now, I think my CV problem could be avoided by using matched
transistor
	>pairs up the ladder. At the moment I'm using CA3046 for the top
and
	>bottom pairs. But I might try matching the others as well.
There is a
	>5mV differential at the top of the chain when modulating the
filters
	>cut-off from 100Hz to about 20KHz. This can only be down to
mis-matches
	>in the chain. Oddly enough it is worse at low Q settings.
	>
	>So who makes the cheapest matched transistor? 

You! 
Match discrete transistors yourself, just as Moog has
described it in the Minimoog manual.
3046's are *not* matched as good as the discrete transistors
in the Minimoog were. 5mV - that's what the 3046's transistors
are matched to. You can easily match transistors yourself to
2mV or even 1mV.
BTW, for CV feedthru it's only important to match the lowest
pair and the highest pair of the ladder.

JH.