Hi,
I was thinking same thing and I tried this with my
Acoustic guitar preset in Axe III (I think this can probably work with electric guitar also).
I added pitch to my Acoustic guitar preset effect chain.
- Placed pitch after amp / cabinet and before chorus etc.
- Pitch (Shift1) value - 12 (one ocatave lover)
- Pitch type is Dual Chromatic (or also can use type Virtual Capo or maybe some else)
- Pitch placed separately from effect chain between cab and chorus so there is two chain in that point to get two sounds
- Chorus gives also feeling like 12 string with Pitch together
- There is other effects on that chain but the idea is to put Pitch as separate (in video you can see that how).
Sound is not perfect but maybe someone make it better.
My playing is not good but hope you get idea and perhaps you can improve that idea and gets better sounds more near 12 string guitar.
I think Axe II also you can make these kind effect chaing to try get 12 string sound with 6 string guitar.
Also some other guitar multiprosessor can make same thing (idea is same in those too).
I haven´t put this preset to that effect change place but if someone wants then I can put preset there.
NOTE: I made this preset to acoustic guitar. I tested with my el.cuitar and not works how I wanted, so only for acoustic.
The best acoustic sound is made with acoustic guitar, so far those I've tested acoustic simulation effects witch el.guitar, they are
not so good as real acoustic guitar.
EDIT: I don´t have any more Youtube video about this (I deleted that video).