Hey there TB, I have a J-Retro 01 preamp that I installed in my MIA Fender Jazz Standard. It came with custom shop single coils and I'm replacing them with the Dimarzio's. However, the Dimarzio's have four wires (red, green, black and white) and the custom shops only had a black and a white. On Dimarzio's diagrams are for preamps with soldering post which the J-Retro doesn't have. Is anyone familiar with this setup? I'd appreciate any help that I can get, thanks!!!