Aesthetix Io Sig vs Manley Steelhead-opinions pls

I checked the archives but wasn't able to find anything of relevance. I too am interested in hearing the opinions of those with extensive experience of both units.

Here it is. I remembered this as it was a result of a thread I posted. And Albert Porter pretty much summed it all up between the 2 units .... and then a few posts down, so did another contributor. I ultimately went with the Io, had Steve Huntley at GNSC do some magic on it over a year ago and he is looking to do more.....this time on the P.S. To evaluate the Io or the Callisto with stock Ei, EH or Sovtek tubes is silly. These things come alive with some tube-rolling efforts.

Thanks Jafox! I'd like to get the Aesthetix 6-box combo but first I'll have to move my Atma-Sphere MP-1 mkIII.

Exlibris, As a fellow owner of the Atma-sphere MP1, I am curious to know what you might not like about it that causes you to want to change to the (very much more expensive) 6-box Aesthetics, fine as the latter preamp may be. Or is it the eternal quest for something different (and possibly better) that drives you?

Lewm,
The MP-1 is the best preamp that I've ever owned.

I've never had an Io in my system but I have lived with a borrowed Callisto Signature (one power supply) for a couple of months. The Callisto does three things better than any linestage that I've heard and these three things are very important to me:

1. huge soundstage: the all-important 'fore-edge' of the soundstage is actually behind me(!) on most recordings. Many linestages present great width and depth but the real magic comes with 'fore-depth'. It 'energizes the room' better than any linestage that I've heard.

2. ambient detail: it presents an incredible amount of information in the air around and well beyond the performers.

3. action: sound from images propels forward in an incredibly natural way, washes over, and engulfs the listener.

These three factors lead to a 'shared sense of space' with the performers. This for me is the holy grail.

The MP-1 is no slouch in any of these areas so to answer your question, there really isn't anything I 'dislike' about the MP-1. In fact, it does a number of things better than the Callisto: it is more dynamic; more authoritative; puts the performers closer to the listener; and is more transparent. It also outperformed the Callisto overall when used with MA-2 amps. I would never think of using a different pre-amp with Atma-Sphere amps.
I should also mention that I think Ralph is the greatest guy in this industry. He is incredibly helpful and responsive.