Korg Poly800/EX800 Users

Hi Poly-Fans,

I know this might be a little off topic now but I've read in this User
Group that there is a reverb/delay mod (don't know which anymore but
any of them is good :DD) for the Poly 800. But there is not much
information about the mod itself here.
Can anybody show me a good describtion of this mod? Any hints would be
great :)
I did the FM mod already as well as a sort of Cutoff/Resonance mod
(it's non-destructive, so I can switch between mod and original state)
and the white noize mod. So the only one thing missing now is delay.
Loooking forward to your answers ;)

Cheers from Germany,
Flo