When I owned the RM-9 I was using Spendor 1/2e speakers. The RM-9 was the only tube amp I tried in my system that I liked with the Spendor's. Normally I have used solid state with them. At the time I owned the RM-9 I lived just a few miles from Roger. So I took the amp over there and he bench tested it with me. Darn if it didn't operate nearly 100% to spec, and put out more watts than its rating.
The upgrade includes the addition of chokes, and new caps in critical places. I think he makes some other changes as well but forget what they are. Roger also does a thorough inspection of the amp and brings it to full spec in all areas. Upon picking up the amp the bench test indicated it was putting out nearly 125 watts/channel. Up about 20 watts from the previous test. As for the sound, I felt the MkI was a bit tubey in nature and with the MkII you will be getting a more transparent and neutral presentation. I myself liked that. I did end up selling the RM-9 and somewhat regretted it. Now I have both an RM-10 MkII and EM7-12v SET from Roger with much more efficient speakers and these sound wonderful.
Be patient with Roger on emails. He is hard to reach as he is quite busy. I suggest you try to reach him through Sal at Audio Summa. You might get a faster response and more information to help you make a decision on whether or not to upgrade.
