Keyboard circuit (was Stretch tuning a resistor string)

[Haible Juergen]

	>That would be the cem3374, dual osc on one chip, single temp ref .

	>Datasheet gives a possible application .  Uses 4051 to switch
between 
	>the ref's of several ic's .  And mux'ed s/h's after the single dac
.
	>
	>The Xpander/M12 uses this chip, uses the compensation, but the
actual 
	>dac arrangement might be different .  Too long ago that i saw the 
	>schemo's to remember correctly .

I don't have Xpander schemos, but what you describe is what I'd have
expected,
sort of. Still one question remains: How did they compensate the external
CV inputs then ? Something like running them thru a fixed-reference ADC
and then thru the regulated-reference DAC ?

JH.