Jfet questions
So I'm currently buying up parts for a couple preamps I'm going to build. PCBs are ordered and I'm going through the BOM and one of the transistors isn't available anymore from where I can find it. I wondered if the MMBFJ177LT1G is a decent replacement for the MMBFJ177? Also the build guide recommends selecting the jfets according to cutoff voltage but I wasn't too sure how to do that or how important it is? Thanks