PT2399 12 string emulator

[psychedelicfish]

I'm very sorry if this post is irritating in some way shape or form, but anyway;
I was thinking about a pedal using a pt2399 to create a slightly delayed signal, then applying some kind of clean octave up to the output of the 2399 (as I understand it, the output from the 2399 is purely the delayed signal) and then mixing it with the original signal to emulate the sound of a 12 string guitar. Unfortunately for me, I'm still a bit of a noob, and am incapable of designing something like this myself. Can any of you who have a better knowledge of the chip (and electronics in general ) help me out?
Thanks,
Edward

[psychedelicfish]

Please don't get too annoyed if this is in completely the wrong place. If this is the case, can some one redirect me to the right place?

[Jdansti]

Your probably in the right place if you plan to do any heavy digital work and programming to get your effect.  You could have also posted in the "Building Your Own Stompbox forum.

Just a little searching on the web reveals that there some choruses that do a pretty good job of emulating a 12 string. You might want to try to find one you like and see if there's a schematic or layout for it.

[anchovie]

There's no way to DIY a clean octave up. that works with chords without using something programmable like a Spin FV1, in which case you don't need a PT2399 as you can write the pre-delay into the code. Is the pre-delay really necessary though? Strumming 12 strings at once isn't really different to strumming 6 in terms of timing.

The really clever way to do a 12-string emu would be getting it to only apply the octave to the bottom 4 strings with a bit of chorus on the whole output. Not a trivial task!

[earthtonesaudio]

...
The really clever way to do a 12-string emu would be getting it to only apply the octave to the bottom 4 strings with a bit of chorus on the whole output. Not a trivial task!

More like a nearly impossible task.  You'd have to be able to discriminate between an open B versus a G at the 4th fret.  To do this you pretty much have to start with a hex pickup.

[yoho]

...
The really clever way to do a 12-string emu would be getting it to only apply the octave to the bottom 4 strings with a bit of chorus on the whole output. Not a trivial task!

More like a nearly impossible task.  You'd have to be able to discriminate between an open B versus a G at the 4th fret.  To do this you pretty much have to start with a hex pickup.

Or remove two upper magnets of one coil of a humbucker and four lower magnets of the other coil and than process both coils seperately...

[earthtonesaudio]

Haha, quite right.  Good point.

[Brossman]

IMHO, any PT2399 delay (especially on the shorter delay times) can sound quite chorus-y, sort of like a 12, also (ie. echo base + modulation) putting an LFO in the repeat path can - at shallow depth, pick ur speed - seems, at least to me, to have an even more pronounced 12-string effect.  This is not as "accurate" as modelling completely. But, respectively, sounds like it'd be a lot easier to DIY than some of the other things suggested so far...

In short, go for a basic bag of pt2399 delay with mods. pick a circuit you dig, and start hacking.

[FUZZZZzzzz]

theres a device called addstring. its a simple device that adds a 'g string' ( sounds sexy) to any guitar and simulate a 12 string. this works really well. maybe if you work with those frequencies.