Elektor Formant Modular

Do any of you fine fellows also possess Blacet stuff in addition to 
Formant? Ive just built a Blacet Miniwave, and (if you guys know the 
miniwave)ive been feeding it a sawtooth from the formant.

Now the Miniwave is not acting quite as expected and Im having 
difficulty calibrating (as I dont own a scope).
The Mini wave is supposed to have a +/-5volt input. 

What is the Formant VCO output? 
should it work OK? if not why not?
(maybe I should just get a Blacet VCO for this purpose?

cheers Mark