I picked up a used D-Tar Mama Bear really cheap last week. Always wanted to try one out. I already own a Fishman Powerbridge but just never had a chance to install it. My question is this, do I need to install the Fishman Powerchip mixer/preamp too? Or can I run the piezo signal directly into the Mama Bear? I don't plan on mixing the piezo signal with the humbuckers. Thanks for any info!