I've suffered for some time with the tuning discrepancy between my 6th course G and its octave. Using 1.40 Pistoy with 0.70 treble gut, they were out by the third fret! Tried 0.725 on the octaveno help. Finally, after attempting out-of-tune tuning compromises, I tried a used 4th course 0.80 treble gut, with a tension increase from 2.7 to 3.5. Bingo! I've not yet tried Dan Winheld's suggested dall'Aquila test, but I'm working up to it.
Regards, Leonard Williams To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html