Switching to solid state amp?

Octave has an excellent reputation, including their integrateds.
As I understand it, and I might be wrong, Gryphon Diablo 120 is not quite Diablo 300 only less powerful. The latter is a reference level integrated. You would want to listen to them both if you considered Gryphon. The phono stage, $2200 option in either, should be excellent. Diablo 120 is $11k and Diablo 300 is $16k, without phono or dac. This would no doubt be different sound - Octave and Gryphon top integrateds.

just made the switch back to SS myself. Went from Rogue M-180's (loved 'em) to Pass X260.8's

There's nothing "modern" about vacuum tubes! Indeed, vacuum tube commerce has collapsed in the 40+ year lapse since I last used a tube-type audio amplifier. All of the principal domestic, British, Dutch, and German producers are now either defunct (like Tung-Sol Electric, my employer from ’57 - ’60), or they’ve long since ceased making tubes. The entire world market for (receiving-type) tubes is now confined to a small coterie of audio and guitar buffs, and served only by obscure Russian and Chinese suppliers with no previous market recognition. (There are other minor sources in former Soviet bloc countries.) The quality and reliability of the tubes made by those arcane foreign suppliers is a subject worthy of concern. And those sources will persist only as long as there’s viable demand, so the outlook for assured access to replacement stock seems dicey. Further, this situation prevails at a time when every instrumented means of evaluating audio quality validates the measurable superiority of modern solid state design, so it's hard to envision an audio future that will extend vacuum tube usage.

@inna  Can you or others provide more detailed information on why the Gryphon 120 is not comparable to the performance level of the 300, other than the power differential? Assuming appropriate speaker pairing, for each. Thanks. 

david_ten, this is just my tentative assumption, not based on any experience or science but only on my impression in differences between the designer's presentation of both. Flemming Rasmussen obviously likes his Diablo 300 and considers it his achievement in the designing of an integrated amp. Diablo 120 presentation sounded like - it is an excellent integrated, better than previous generation Atilla, but..
However, this is my impression and speculation, that's all.