I have been listening and comparing both great preamps for more than a month with great enthusiasm. My front end is a vintage Forsell Air Reference CDT, LDM server, Lampizator Pacific Balance, Atma-sphere MA-1 and Audiokinesis Azel Tower.
The Aesthetix Eclipse comes with dual power supplies (optional) and remote control (optional). Atma-sphere MP-1 comes with all the optional packages like, volume control, V-Cap for Linestage and throughout, caddock resistor package, phono, low output MC, damping package. The only option excluded was the caddock for the volume control.
Advantage of Aesthetix: this is suitable for tube rolling freak. It needs a total of 24 tubes to function. Each PS has 2 x EL34 and 6 x 12ax7. The Linestage itself has 2 x 6sn7, 2 x 12ax7, 4 x 6922.
Sudden loss of power / blackout won't post any harm to the whole systems. I lost count on the tube rolling with this preamp.
Not so sensitive against microphonic tubes, at least from my personal observation.
Looks more appealing in my taste, though this is truly my subjective views.
Disadvantage of Aesthetix: takes up more shelves space, more power cords. There are a total of 4 boxes, 2 power supply (the standard version is single PS), the linestage itself and the smaller box for motor controller of the volume control.
Very heavy and need two guys to carefully place them on the shelves, to be safer.
Tube replacement would be costly judging from the number of tubes used.
Need to purchase another phono stage in case that I will delve into analog.
Never ever unplug the umbilical cord on the Linestage immediately after power off. It will take about 20 minutes of more before you can unplug the umbilical cords otherwise, the whole unit needs to be shipped back to factory for repair.
Advantage of Atma-sphere: simpler designs. You need 6 x 6sn7 and 10 x 12at7 (for the phono section).
Though it's physically wider but in overall, it's smaller and lighter. So one man can easily move it into position.
Only one PC is needed to power up the PS and unit already come with its single dedicated umbilical power cord.
Optional feature includes the phono stage which is still affordable.
Disadvantage of Atma-sphere: this is more sensitive towards the tube quality. Once you have a microphonic tube, when turning the volume up and down, the noise will come out from the speaker.
Tried rolling 6 x 6sn7 NOS tubes and finally, I returned to its standard Chinese tubes for better result.
During start up, the instruction is clear, never ever turn on the amp before the DC offset LED disappeared. Though never happen, I'm quite worried about unexpected blackout where my amp will automatically up when power is on but the preamp is still neutralizing its DC offset. Knock on wood what would happen if such possible scenario takes place.
Characteristic of Aesthetix: more relax, deeper sound stage, with multiple layers behind the front wall. Better bass slam and almost SS like type of sound.
Characteristic of Atma-sphere: crazy dynamic and very explosive attack, bass is solid yet not as deep as the rival. Master of pin point. Lush vocal without veils or whatever you call it. Sounds more direct and slightly forward on certain tracks.
Similarity of both : both are holographic and musical. Both presents the detailed yet liquid sound. Throw in any kind of music genre, they will do their job well.
Verdict: both are pleasant to listen to even for a very long listening session. I could listen to my systems for more than 6 hours straight. Aesthetix is almost SS like in terms of slam and bottom end while Atma-sphere is more tube like sound with sufficient LF. I can't decide which is better because I love them both.