Would There be a Significant Difference

IMO it's a no brainer go with the Benchmark preamp for eliminating any synergy issues. 

Many thanks for the great and useful comments. I have narrowed my preamp choice down to two tubed brands, either Rogue Audio or Backert.  Right now, I have an opportunity to audition the Rogue RP-7 AND the Backert Rhumba 1.3 at home for a week.  In the store—with components well above my own, I liked the tonal qualities of the Rogue and the imaging and soundstage of the Backert, leaving me in something of a fix.  I will have to make a choice in the next week, but I am wondering if I should look at the next higher models from these two companies, the Rogue RP-9 and the Backert Rhumba Extreme 1.3, which are the same price, at $7500, roughly 50% higher than the models I am auditioning.  There are few reviews of the Rhumba 1.3 but many highly laudatory reviews of the Rhumba Extreme.  Or, in that price range—and staying with new equipment, should I consider something like the McIntosh C2700 or some other model?  The $7500 point would have to be my absolute maximum—plus “the governor’s cut” via sales taxes.  My thinking is that stepping up a notch from the RP-7 and the Rhumba would give me “headroom” for future upgrades to my sources and my power amp, without having to upgrade the preamp once again.  Again, thank you in advance for any advice you can offer.

The difference between the presentations of the Rogue and Backert pres may be quite different in your system and room that at the dealers.

Take advantage of this opportunity. 

@mike4597 I auditioned at home the Rogue RH-5 (which like the RP-7 has balanced in and out) and the Backert Rhumba.  I found them more similar than different, but ended up preferring the Rhumba by a hair.  Will be interested to hear your experience with the RP-7.

In response, especially to “twoleftears:”. My wife and I spent several hours this afternoon listening to our system with the Rogue RP-7 replacing my RP-1.  The difference is simply stunning … and wonderful.  We listened to Beethoven’s Pastorale (we attended a performance of it in Berlin in 1976, with the Berlin Philharmonic conducted by Karl Bohm—the Berliners went wild in response … well, at least the German version of an upper crust audience “going wild”), some Moody Blues—esp. “Never Comes the Day,” Fleetwood Mac, the Local Hero album, Bing and Gary Crosby together, Strauss waltzes (my wife’s favorites), and others.  We experienced wider and deeper soundstage, more accuracy in instrument representation tonal characteristics and placement on the sound stage, and clarity.  It made the RP-1 sound as if the music had momentarily gone through a blender; even that is overstating it a bit, but not much.  Also, a bit more bass, but it was tight and well dampened, not muffled and overhanging. The tonal characteristics are similar, but the RP-7 is more precise without becoming too dry or stilted.  The RP-7 would be a MAJOR upgrade.

Tomorrow, I will put the Backert Rhumba in the system and listen to the same music, … perhaps even more.  At the vendors location, the Rhumba had a better sound stage representation, so I am anxious to hear it in our living room.  And, I am now wondering if the Rhumba Extreme would be a marked improvement over the Rhumba, given that it has most of the “innards” of Backert’s flagship Rhythm in the Rhumba chassis.  By the way, I called Backert  late this past week and had a very pleasant conversation with their President, Andy.  He actually said the Rhumba would be such an improvement over my RP-1 that I would be shocked, and that I might not even need the next step up, to the Rhumba Extreme.  Andy provided lots of information in a very engaging conversation with no sales pressure.

I am expecting—and hoping—to be shocked tomorrow by the Rhumba.  Report and decision to follow.  Thanks for the comments, folks!