@plga I use Allnic L3000 Mk2 with my LM 508. I know that doesn't answer your question as it's an all tube pre. However, Allnic is very neutral and balanced. It takes the LM to a new height (albeit transparency is reduced) allowing all the SET magic to shine and adds weights/authority/fullness to the bass.
I think if you are looking for a SS pre, make sure it's utterly transparent and neutral such that it doesn't mask the SET beauty of LM 508.
I think if you are looking for a SS pre, make sure it's utterly transparent and neutral such that it doesn't mask the SET beauty of LM 508.