Aesthetix Io Sig vs Manley Steelhead-opinions pls

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.

I cannot comment on the Manley, however, the Aesthetix IO Signature is an outstanding device when you desire an all out assault on vinyl. It leaves me missing nothing. I have seen various posts in this forum about IO versus other phono stages, the one most common trait is that the IO gives you outstanding dynamics, stage and width. Others have commented about some tube rushh, hey this is all out tube unit BTW, well, I do not notice any tube rush as a detractor to any of my listening sessions and what there is of any tube rush could only be heard at 0300 on the volume control, unreasonable listening levels by any measure.

I use the stock Sovtek tubes and will dabble in tube rolling when these start to show their age, but for right now the stock tubes are great. One other note, the Manley Steelhead was a close second on my list.

If you have the space for the IO, I would think that would be the last component you would ever think about upgrading.
Ciao,
Audioquest4life

I just re-read my posting about the three strengths of the Callisto Signature and realized that none of the three were directly related to the actual sound of musical notes.

You've probably seen Chinese brush paintings where the subject matter is typically bamboo and the medium for the painting is simply black ink? What makes one painting great and another poor is not primarily the representation of the bamboo nor the appearance of the black ink, it is nature of the white space, the empty space, around the black ink.

Dear Exlibris,
Oy!
I think you've been sipping the same suspect brew that used to affect HP's conceptual powers in strange ways. But, I got it (I think).