I'm making my first foray into DIY with a crossover kit from John Pomann. This will be a three way L-R using Burr Brown Opamps. I don't mind the opamps on the low pass, but would like to ultimately replace the ones on the mid bandpass and high pass with discrete buffer stages, perhaps using a FET. As a beginner I'll need my hand held on this one. So any simplified instructions, schematics, explanations and recommendations are heartily appreciated.