I think they still can but Zach responded to my reply about the Atrium vs the Caldera on the Felks Envy and said something about how the dynamic drivers have a bigger range of variation than Planars. I’ll try to find his reply.
I heard the Atrium and the Caldera on the dcs Lina stack ($30k) and felt both just sounded ok. Really believe the Caldera sounds better on the HE. But then switched to the Felks Envy and they both improved but the Atrium just shined. Very liquid sounding especially in the mids. More musical than the Caldera. When I got to the Ferrum Orr, which has a similar punchy, textured sound like the HE, the Caldera sounded better than the Atirum. More detail, control, texture. And maybe if had the choice, the Atrium with Felks Envy would be overall winner.
If you want a good SS amp for the Atrium why not try the new Homage amp? I only got to try with my Caldera and it was just ok. Not sure the impedance setting. Just didn’t have the same punch and weight of the HE but that switch might have made a difference?
I found his post. I really doesn’t give preference to SS vs tube, just that dynamic scale differently. So the Atrium are 300 ohms while I the Caldera are 60 ohms and the Utopia are 80 ohms. So could be how they tuned the HE to work best with Focal and sounds better with lower ohm headphones.
https://www.head-fi.org/threads/zmf-caldera-new-planar-magnetic-from-zmf.964836/post-17833131