Once again The Trident!

[Haible Juergen]

	>The Moog oscillators that used a common expo converter for multiple
	>oscillators, was that voltage or current?

Current.

	>You could also do the same trick with an expo current source. Drive
linear
	>CCOs from one expo converter using a resistor splitter and offset
one CCO
	>from the other by injecting additional current at pin 5 of a 3080.

Same trick means lin detune ? Yes, sure, that works. But the additional
current
will be *tiny*. Just using a large resistor is not - you'd end in the Giga
range.
So you'd really need an extra expo current source.

	>What I did was add 56K/1K attenuators to each additional base
input. You can
	>now offset each one of them with a voltage, but they will still
track the
	>common emitter input at 1v/octave. This works good for multi
section filters
	>(like 8 parallel bandpass). I don't know if tracking will be
accurate enough
	>for multiple CCO cores.

I don't know if it's good enough for transposed CCOs either (I expect so),
but
I've been using this trick for variable slope filters for years. (An old EN
article suggests
extra expo converters, but a single shared one with one transistor for each
partial filter current works nicely).

JH.