Removing the preamp from Ovation guitars for replacement or upgrading can be accomplished with common hand tools and minimal experience. The OP-24+ preamp outfitted on many Ovation models has a separate battery compartment, guitar cable jack and pickup, which must be removed in addition to the preamp. Other Ovation preamp models with integrated battery compartments are removed in exactly the same way as described, except for the additional battery compartment steps.
Remove the strings from the guitar by turning the tuning keys counterclockwise, unwrapping them from the tuning key post and pulling them through the holes at the bridge.
Remove the plastic saddle from the bridge by pulling straight up with a pair of pliers. When the saddle is removed, the pickup will be visible. The pickup is a thin metal strip with a wire attached, which is inserted into the interior of the instrument through a small hole. The pickup is not glued or otherwise anchored to the bridge and is held in place by the aforementioned saddle.
Place a hand inside the guitar's sound hole and locate the pickup wire underneath the bridge. Grasping and pushing the wire upward will enable the pickup to emerge from the bridge for removal later.
Remove the guitar cord jack securing nut on the underside of the guitar by turning the nut counterclockwise with pliers until it is fully removed from the jack.
Remove the battery from its compartment by depressing the exterior latch. The battery will pop out of its seat and pull out easily.
Place a hand inside the sound hole and locate the plastic clips on either side of the preamp unit. Depressing the clips will enable the preamp to be pushed up and out through the top of the guitar.
Place a hand inside the sound hole and locate the two plastic clips on either side of the battery compartment. Depressing them will allow the compartment to be pushed up and out of the guitar.
With a hand in the sound hole, locate the pickup wire underneath the bridge, trace it to the preamp and pull from its socket. The pickup may now be removed from the bridge, along with the attached pickup wire.
Push the battery compartment and preamp out through the top of the guitar with a hand in the sound hole and detach the two battery wires from the preamp by pulling them from the sockets. The battery compartment is now removed from the guitar, and pulling out the preamp will take the cord jack and attached cable along with it.
If having trouble locating internal wires and mounting clips, insert a small inspection mirror with a telescoping handle into the sound hole to assist in visibly identifying these parts. These mirrors are available at hardware, automotive and electronic supply stores.
When removing the plastic bridge saddle, grasp gently with pliers to avoid breakage. A broken saddle will require replacement.
If the purpose of removing the preamp is to install a different brand, it is best to have a professional perform the install. Ovation preamps are proprietary and the guitar will require modification for a correct fit. Modification requires cutting into the guitar and serious damage can occur if done improperly.