I found an recent review of the Octave MRE 130's. It is in issue 37 of the online zine, Tonepublications.
It is a pretty interesting read;
http://www.tonepublications.com/MAGPDF/TA_037.pdf
What caught my eye in the article was the reviewer opted to try some KT120's and replace the 12AU7's with the new Psvane equivalents. I ordered the same tubes the following day after I read the article. The KT120's do add some more bass, a noticeable increase, and the dynamic range does seem to be greatly increased. I do not have but 10 hours or so on these new tubes. Compared to the EH KT88's, one of my favorites for the MRE 130, and the Svetlana Winged C, another favorite of mine for the MRE 130, these seem to have all of the traits I like in both those tubes. One caveat, the midrange is really pronounced. It is not bad, but may be irritating for an extended period of listening at higher volums. I think it will settle down some after a few more hours. Overall, I am satisfied and I am optimistic the pronounced mids will settle down. These tubes do provide more of everything, more highs, more mids, and a pronounced deeper bass.
I have experimented with the sub on and off, and these new tubes are really giving the sub a run for the money in my current configuration. I mean the bass does have a more subterranean note. Note I am driving B&W 800's.
From the music I have thrown at the amps, Kansas (Lefoverture), Miles Davis (Sketches of Spain), and others such as Robin Trower, the music is detailed, has wide separation, and is stunningly captivating. I believe these new KT120's are a pretty good match with the Octaves.
Fellow Octave owners please continue to post your experiences, tips and tricks, mods, and whatever your experiences may be with Octave in general.
Thanks.
Audioquest4life