in case you don't: keep in mind that the scaling and parameter ranges of those old synths vary a lot. take two real prophets and compare them side by side: they will sound different and behave different. 30 years and also environmental influences do a lot to analog circuits. on top, in many cases, things were altered during the entire production run. sequential did this a lot, those synths were pretty much hand made and changes + improvements of the PCB were nothing unusual.