You could add the Aesthetix Pallene, though not sure if its sold in Signature (yet). Backert Labs also shows up alot in the RP7 area.
Upgrade from Rogue RP-7
I currently have RP-7 pre which I am looking to upgrade. I will be looking at preowned equipment. Some of the pre's I have been reading good stuff about are listed below but I dont know if there is a definite pecking order in terms of SQ. I listen to mostly Jazz, Vocals some classical bit not a lot. My power amp is a CJ Premiere 12 monblock (and soon NAD M23 for a summer amp). My speakers are of my own 3 way design 12/5/1 drivers. You advice and thought are appreciated. Thank you.
Ayre KX-5 Twenty
Bryston BP 17 cubed
Aesthetix Calypso (Signature?)
Rogue RP9
Zest Leto.