The EVH and the older Custom Shop Phase 90 are just the standard Dunlop MXR Phase 90 with the R28 mod, whereas the '74 Reissue Custom Shop handwired pedal (and the Whirlwind Orange Box) have the original script circuits, and sound closer to the original script Phase 90's. There are more differences in the vintage script Phase 90's than just the one or two components that are changed in the R28 mod, actually other component values are also different. If you really want to mod your stock Phase 90, there is a schematic with the approx. 5 component changes that are required to make the modern Phase 90 the same as a vintage script model. It's in the "Wiki" on the DIYstompboxes.com site, go to the Wiki and do a search for "Phase 90 script mod" or something like that. It tells you each component and what change is needed to it.