I am very late to this thread, I know. However, I thought I would chime in with my Aesthetix Calypso vs ARC LS25mkII experience. I owned both. The Calypso is a warmer and more robust sounding line stage while the ARC sounds neutral to too lean and clean in my system.
I had the ARC LS25mkII for a couple years and then began my search for something about as flexible and versatile but more to my liking. The only thing I could find that came close in terms of "flexible and versatile" AND sounded a bit more "tubey" (which is what I wanted) was the Aesthetix Calypso.
I liked the Calypso so much that I later upgraded to the Calypso Signature. End of story.
I had the ARC LS25mkII for a couple years and then began my search for something about as flexible and versatile but more to my liking. The only thing I could find that came close in terms of "flexible and versatile" AND sounded a bit more "tubey" (which is what I wanted) was the Aesthetix Calypso.
I liked the Calypso so much that I later upgraded to the Calypso Signature. End of story.