Elektor Formant Modular

Hi everyone!
Im pretty sure that my VCO�s are out of tune, I dont really notice
because Im usually only using notes that a few tones apart, an octave
or two at most. But when I sat down the other day and made a 4 octave
jump C1 to C4 on my sequncer, the C4 sounded almost a whole tone out.

Checking the docs on the procedure, I gopt very confused. I was
expecting a trimpot to adjust the scaling, maybe 2 (course and fine)
but... the manual describes all manner of strange techniques..
involving voltmeters and oscilloscopes!!! I DO have a voltmenter of
course, but I simply did NOT understand the manual.

PLUS when I DID try the trimpots mentioned in the manual, not much if
anything seemed to happen...

Can someone run thru the procedure, in laymans language please??

Cheers..

Mark