Are the creation of .FO and .ADD files essential before creation of segments with Direct Signal? The text on page 27 of the manual implies they are (“you must take the exact name of the analysed file so that the procedure may access the .F0 and .ADD files.”).
However, the diagram on page 6 seems to show that using Direct Signal can ‘side-step’ the creation of fundamentals.
I hope someone can clarify.