Ok, so I guess I need to add some details. Warmth to me is more "meat on the bones" in the midrange. It’s not the low-end. The Rogue (and I apologize for the initial misspelling) is a great preamp, especially for the price, but it’s a bit lean in the midrange (and yes, I have tried different NOS tubes and although better, not all the way to where I want it to be). The other area where it falls a bit short is soundstage depth. The width is ok, but it’s lacking depths. This is not the speakers or the room. With the Gryphon Diablo 300 (way overkill with the ZU’s) I had that, so it’s definitely possible.
As to the nonsense about power condition limiting the current etc. 8W 300B monoblocks doesn’t draw that much current to start with and if the power conditioner (PS Audio PP12) doesn’t limit the Gryphon, I really don’t think it’ll limit the Coindicent Frankensteins...
The Zu Omen Def Supreme can indeed sound harsh unless you set them up correct. It does take lots of tweaking to get them just right. And I’ve done that. With other amps, I can get them to sound almost sweet, just not as seductive as with the SET amps. Trying other preamps, I can change the sound, but again, I haven’t found "THE ONE" yet (hence the post here).