Rogue RP-7 vs. New RP-9 - What's the Difference?


I just got an RP-7 recently and I went to their site to look up the manual as I was setting it up and I see they now have an upgraded RP-9 model with different tubes (Russian 6H30P vs 12AU7 in the 7).  I can't seem to make out any other differences.

I thought this might warrant a discussion from those who know more than I do. Thoughts?
irrenarzt
Chassis dimensions are identical for both, but that makes sense as they mention their "award winning RP-X hardware and software platform", which indicates to my mind that they are using the same base to work off of.

Audio Research's well received Ref 10 preamplifier utilizes (8) 6H30P's. The RP9 uses four.

Rogue msrp $7500 vs ARC msrp $33,000.

Looking forward to hearing the RP9! Always a great value product.