The Ref 5se is a truly excellent preamp. At the price it is selling for used right now it would be very hard to beat. At it's retail price it is hard to beat. I own a Ref 5se and it is amazing. I listened to a lot of preamps while thinking about upgrading. I heard the Aesthetix Calypso signature in the same system as the Ref 5se. It was not in the same league. The Pass XP-30 is very nice. I have not had the chance to directly compare the XP-30 to the Ref 5se. But I was very impressed by the Pass system it was in. If I did not own Audio Research gear I would probably own Pass. The D'Agostino Momentum preamp is maybe better, though it is far more expensive. I do love the Captain Nemo styling. I can't think of any preamp I liked as much as the Ref 5se other than the D'Agostino Momentum.
What's a contender to an Audio Reference 5 SE?
If you were considering an Audio Reference 5 SE to mate with a Plinius SA-Reference amp, what other preamps might you consider?