Digitech has this new pedal called the Mosaic that simulates an electric 12-string guitar pretty convincingly. as far as i can tell it achieves it with some pitch shifting, detuning, and maybe a little delay. has anyone tried to achieve this effect with their H9, and if so can you tell me which algorithm you used along with setting tips?
The Mosaic doesn't use crossovers to emulate a 12 string's usual tuning [high E & B strings unison; lower four strings in octaves]. So it should be easy enough to cover the octaves & unison on every string. The Tone control's targeting effects might be something you'll have to do outside the H9.
There's a [F]actory preset in the HarModulator algorithm called ELEC12STRING ROO. It's a good place to start. Dry + unison + 1OCT, with offset delays to simulate doubled strings. I happen to like a little more 'octave' in the mix, and the cyclical modulation there is a little too deep and regular for my tastes.
I went with 2 pitch shifts an octave up, a lighter mix, and slightly longer delay times. Modulation is envelope controlled, and shallower (but spread out: up & down 3 cents). The expression pedal maps the Mix from 25-50%, and the Mod Depth from -3c to -8c, for a deeper variation under foot control.
The HarModulator, Diatonic, and QuadraVox algorithms may be the best bets for more natural 12- and 18-string presets. The H910 / H949 is perfectly serviceable for any of this, and my first choice for 'glitchier' alien 12-strings. There are several other algos to work with for variations that include reverb, or more exotic & 'unnatural' 12-strings.