Stenho, I've owned most of the preamps that are considered "ultimate" and borrowed a good many others. I could list and describe them in a email if you wish.
I am so completely sold on both the Aesthetix Io and Callisto that I have stopped looking to upgrade that part of my system. You would have to know me to realize how radical that is :^).
I did not see the Foundation Research, at least that I can remember. I understand that it is supposed to be good. Same with the new Burmeister preamp. A reviewer (friend) is currently trying several of these in his own system. His reference is the same as mine, the Aesthetix Io and Callisto. He too has been unable to find anything their equal.
I am so completely sold on both the Aesthetix Io and Callisto that I have stopped looking to upgrade that part of my system. You would have to know me to realize how radical that is :^).
I did not see the Foundation Research, at least that I can remember. I understand that it is supposed to be good. Same with the new Burmeister preamp. A reviewer (friend) is currently trying several of these in his own system. His reference is the same as mine, the Aesthetix Io and Callisto. He too has been unable to find anything their equal.