Using a capo on a 12 string guitar was a bit of a challenge and involved lots of tinkering to fine tune – until Nick Campling of the G7th Capo Company came up with the compensated capo which allows all the strings to be held down evenly without having to tighten it up really hard.
In this video Steve uses the G7th Newport 12 string capo on the tertz guitar that he built and its amazing how easy it is now to capo up without lots of re-tuning – in fact, with no retuning at all, as demonstrated. Well done Nick and G7th! (And well done Steve!)