I don't own the Primaluna Dialogue2, but the Dialogue1 for the past 6 or so months. First-off your experience is completely opposite of my experience. System synergy is a must and looking at your components I suspect it is your ancillary equipment that is a major contributor or culprit of the harsh, etched sound.
Out of the box my unit sounded ok, yet as is typical everything needed to be broken in. I knew before I bought the unit that I would roll-tubes to find the sound that I wanted. My unit came with Primaluna EL34s as well as their standard complement of 12ax7 and 12au7. As the unit was breaking in the violins, for example, were a bit much and irritating and the sound was thin without much warmth and lacked weight and body; but as the unit played on changes for the better began.
From experience I knew where I was going with respect to tubes and I started by first replacing the standard 12au7 with RCA Clear Tops which I had on hand. Nice improvement everywhere, but especially in soundstage width and depth. I kept playing and listening, and changing these tubes: NOS Sylvania, Mullard, Amperex, and so forth, each one better than the stock tubes. I also did the same with the 12ax7. And the music played on, warmth, body and weight, dynamics, lovely highs, Ella was in my room, Miles too, Louis Armstrong trumpet about perfect, rock rocked, small and large classical pieces sounded right, excellent timbre in a coherent well-defined stage. But I still knew it could get even better.
So I dropped in some SED Winged C EL34s, nice improvement again more warmth and body with no loss of detail and all the other attributes. It was coming together, rolled some more and finally settled on NOS Russian 6n3ce (6L6), Amperex Bugle Boy 12au7, Sylvania 5751 3M Black Plates.
Now, to my ears, in my system and space, the Primaluna has proved to be a versatile integrated that makes wonderful music in my office system set-up. It really loses nothing in comparison to my main system (Cary v12 and SLP98). A little different presentation, but it keeps up with the big boy and plays music as it should with all the Audiophile and music lover attributes. I have also compared the Primaluna against my Cary CAD 300sei, new Almarro 205 and my brother Leben 600 integrated. You may prefer one over the other, but the Primaluna is a stellar performer, and yes, I just love their adapive auto bias.