Aesthetix Io Sig vs Manley Steelhead-opinions pls

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.

I have an older (very much older) MP1 that I purchased used and in virtually non-functional condition. Therefore after purchase I was forced into DIY mode, both to fix it and to update it to what were then Mk II specs. This took more than a year's worth of my spare hours. Ralph and his group at Atma-sphere was a great help in this endeavor. (At the time, I owned an MFA Luminescence, as a user til the MP1 was "finished".) This all happened about 5-6 years ago. Then as of last year, and after a great deal of study and brain-picking, I took my MP1 into the great unknown, making several more mods that are similar to the Mk III version but also reconfiguring the phono and linestage circuits in ways that could not really be done in a production unit (e.g., using battery bias in the phono input stage and in the circlotron output stage). The results are fabulously good; the phono is by far the best I have ever heard in my system and with tons of gain for any LOMC. I'd love to compare it to an Aesthetix or Manley (or Raul's phonolinepreamp), to see where I'm at with it. Vinyl now so blows away CDs that I really don't bother with listening to the latter. If anyone with any of these or other top drawer units resides near to me in the Washington, DC, area, perhaps we can have some fun comparing preamps.