Looking for a well matched Preamp. Pls advise!

Thank you. Not sure that’s enough of a discount from new. 

Given your other equipment probably a Schiit Freya+.

Is the Schiit Freya+ with the upgraded tubes, really as good as the Rogue?

The Freya and Rogue are both quality components. You need to figure in tube costs as stock tubes are merely adequate. The RP-1 has 2 less tubes and uses the 12au7 tubes, which are fairly common and easy to source. It also has a phono input.

Schiit has quite a catalog of components and is known for excelling in Dacs. The Freya may run hot, which could create problems in a small room or one with poor ventilation. Usually there are some available in secondary markets.

The RP-1 is a great selection, you would not be disappointed. Although, you may want to consider a Sphinx integrated. Your Adcom, while dated, still carries value and a used Phoenix would be on par with the cost of an RP-1.

The kicker is if you stay with components, expect the ladder upgrade affect that may never end. Or, just buy an integrated to avoid the constant madness in search of musical nirvana.