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.




What sound characteristics are most important to you and what improvements are you looking for?

Clarity, timbre should be dynamic but doesn't have to lead the group as long as it does not sound constrained. good separation of instruments. I dont believe my RP7 is as clear as it could be. In its price range it is good but i am willing to spend more to get more.

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. 

I recommend researching the Holo Serene KTE.  Look up on-line reviews and YouTube reviews.  I bought one and compared it to my McIntosh C2600 and a Linear Tube Audio Microzotl Reference preamp.  I sold my C2600 after owning it for 5 years and I returned the LTA preamp under the 14 day trial.  Herb Reichert of Stereophile uses it for his reference preamp.  It's less expensive than the preamps that I compared it to and less expensive than all the preamps on your list.  

I liked the Serene KTE so much that I have a second one on order.  That one will replace my Audio by Van Alstine FET Valve CF.  The Serene is about as transparent as I've ever experienced in a preamp.  It produces a deep soundstage and great separation.  Tonality and timbre are very natural.  It reproduces piano and the human voice in a lifelike manner.  Don't let the $3k price tag fool you, it competes with preamps 2-4 times its price.