Perhaps a really dumb question but can you run a pickup with an onboard preamp through an external preamp? If you have a passive pickup (K&K) I assume there isn't enough voltage to push any volume but if you have a simple onboard preamp (Fishman Prefix) and want to equalize etc. can you run through another preamp? Should you remove the battery in the guitar?
Thanks!
Acoustic Preamps and Passive Pickups
BigBear--If you are just looking to equalize and filter post-preamp you can run it through a direct box (I use an LR Baggs ParaAcoustic DI). I use a passive K&K pickup and get plenty of power to the amp with just a direct box. I don't see any problems with using it in conjunction with a preamp. The direct box acts as kind of a preamp but should be fine to connect to the output of a preamp. If you have a local music store you can ask if they'll allow you to bring in your setup and play through another preamp just to answer your question.
By the way, even without a preamp or direct box my passive pickup gets a surprising amount of power to the amp!
By the way, even without a preamp or direct box my passive pickup gets a surprising amount of power to the amp!