Aesthetix Calypso vs ARC LS25 MK2



Looking for insight from folk's who have compared these two pre's either head to head
in the same system (preferably) or experience with both in different systems.

I'm not looking at any other pre's at this time,
so please don't muddy up the thread with other pre's I should consider.

Thanks in advance...
perfectionist
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've owned the standard Calypso, but sold it along with my tube amp thinking I'd enjoy the simplicity of an integrated amp... turned out to be a mistake that was regrettable. Now I'm back to separates and stepped up to the Calypso Signature. Both preamps are great values IME, with the Signature providing additional resolution, transparency and a larger soundstage. Swapping out the stock tubes with carefully selected NOS tubes is a must in both units.
Swapping out the Calypso tubes is easy and inexpensive......right? They only have 2 12ax7's per channel. What was your final decision on tubes???