Tempco Source/Analog vs Digital DIY

[Ingo Debus]

Fraser, Colin J wrote:
> I used 12 bits for hz/v on my homemade convertors, but didn't include
> pitch bend so I didn't need the extra resolution.
> What I'm thinking about now is a digital exponential convertor for vcos.
> Has anyone tried something along the lines of a linear input to an a-d
> convertor driving a rom with a lookup table for exponentiation, the
> output of which drives a d-a convertor, all clocked at audio rates to
> allow audio fm ?

I heard about a synth that used an 8 bit D/A generating the reference
voltage for another (multiplying) 8 bit D/A. The first D/A selected a
pitch range (an octave for instance, don't know how large the range
actually was) while the other one does the fine tuning.
This synth was the "tiracon 6V".

Ingo