Interestingly, my experience is the very opposite, but with a few qualifications . Timbre on the CA-1a in its default configuration is unapologetically and unambiguously terrible. The clarity especially in the mid range is really lacking and grainy. Only redeeming quality for me is its bass. First thought to my mind was that, it sounds like a broken Expanse.
When I add the star8 cable to the CA-1a and or apply the filters it becomes absolutely wonderful! Timbre issues become almost negligible and its technical performance is nothing short of prodigious. It's like audio alchemy. I personally prefer to not use EQ which is why I think I have gravitated towards the Stealth for quite some time now, but to my ears CA-1a with applied filters makes a compelling use case.
I am inclined to agree here though I'd caution about formulating an opinion about Expanse or Stealth from Can Jam. The DCA headphones seem to index higher for tonality and timbre than delivering the raw energy of the performance. I think Expanse due to the slight mid-bass heft conveys this energy a bit more than Stealth. The CA-1a even a bit more so. I'm personally satisfied with the dynamic impact on DCA headphones in my system, but whether that's enough to satisfy those masochistically seeking it is another thing all together.