The ML 38S is an excellent preamp and will sound fine in ANY system!
See, I cannot agree with this statement.
That is where synergy and subjectivity come into play.
Personally, I owned the ML 38S for a few weeks (over a decade ago), and I did not care for it at all. However, the gent that I bought it from loved it, and the gent that I sold it to loved it. So I would never say that it was bad gear, it just didn't suit my system/tastes at that point in time.
So it's all about system synergy and personal tastes. That is why I told the OP to just enjoy what he has if it sounds good to him.
I did not mention my poor experience with the 38S, because that is irrelevant.
From my experiences, ALL gear can sound great with the right ancillary equipment. There is no one piece that sounds great with everything, just as there is no one piece that sounds terrible with everything.
It's all subjective, and system dependent.