@immatthewj apologize I probably should have clarified that early on, I did not run the gold pin EH, and cannot speak for those, I was referring more to the original EH which came stock in my 98 and those are metal pin, not gold pin.
@billpete there are two pairs of course, 2 - 6SN7 buffer cathode followers, 2 - 6SN7 line stage. The front two are for the gain stage and apparently play a crucial role in amplifying the signal before it is sent to the output stage. Most recommend placing higher-quality tubes in these positions to achieve better sound quality.
I’ve played a bit putting the more transparent in the front, and then vice-versa, with the softer ones in front. Whatever sounds signature I want, I put the opposing pair in the rear as one approach. Another aspect I like about this preamp and why I keep it.
Gold Pin EH - probably best to share your experience here for others as I’ve never tried them, and just jumped up to other tubes as those gold pins came out later.