I have had the Amp (Cary120S Mk2) back from Cary for about three weeks now. The improvements are clearly audible and very pleasant. My impressions so far would be that the upper end is a tad bit leaner (by no means dry) with a tremendous amount of air surrounding instruments such as cymbals, bells and triangles. A cleaner, deeper view into the soundstage. Dialog has been improved to the point that you can almost see the expressions on the singers face as they finish there lyrics, a greater understanding of the music. The Amp now has 28 db of gain and is very easy to drive. The magic in the Midrange and Bass has been improved also. Female vocals and Piano are stunning!
My only regret is that I can't tell you how much the Amp revision or the Psvane 12AU7 tubes contributed to the improved sonic quality.
I was listening to an old Richard Goode (Who I had the pleasure of attending one of his concerts in Carnigie Hall) CD of Beethoven Piano Sonatas a couple of days ago and the Wife asked who it was? She said the piano sounded very nice, like a real piano in the front room. That blew me away as she very seldom comments on any thing I play except to say "Turn it Down!"
My system consists of Harbeth Compact 7 ES3 speakers, Cary Preamp SLP03 and Cary Amp 120S Mk2, and a Sony XA5400ES SACD with Harmonic Tech. Magic speaker and interconnect cables.
As mentioned above the Amp has KT88 and CV181-Z Shuangung Treasures and the Preamp uses Shuangung Psvane 12AU7s.
If I get good life out of the Psvane tubes (yet to be seen) I will continue using them and as of now can recommend them highly. Dave