LR Baggs M1 acoustic preamp / pickup

[PMowdes]

Hi

Does anyone have any experience building an acoustic preamp.  I've been asked if something like the LR Baggs M1 is possible.  

http://www.lrbaggs.com/pickups/m1-acoustic-guitar-pickup

I've seen the board attached to the guitar jack and it is all surface mounted but there are relatively few components.

I was looking for a schematic but I haven't had much luck.  Would there be any special considerations around it being hooked up to an active pickup?

Cheers

Phil