I’m wondering if the RP-7 can also benefit from upgrading the coupling caps - the EVO Oil is not a super cap...
I make my own speakers, and I use Mundorf Supreme Silver Oil, Duelund Cu, Jupiter Cu caps in the crossovers, and I find that they render a more mature sound than EVOs.
Interesting! I’d also upgraded from the Rogue Apollo monoblocks (plain white M-Caps) to Apollo Darks (EVO silver/gold/oil caps), and I’m not sure I really enjoy the Darks any more than the standard version. When their top 6H30 preamps were Rogue Athena & Hera, they used standard Mundorf Supreme caps and I really liked them! I’m definitely suspicious that I simply don’t dig the EVO’s voicing. Don't get me wrong, I still love the Apollo Darks - they can rock like crazy - but they do better with warm partner gear. The pairing with RP-9 was way on the other side of that lol.
I also have VAC gear which uses a mix of Genteq and Jupiter / Beeswax coupling caps - and for numerous reasons including cap selection, I’m sure - these components always sound warm and sweet.
I have sizeable stash of vintage 6922 / 12ax7 / 12au7 / 12bh7 tubes here too. When the 6H30 sound is "right", I love it and am content to not roll.