Calling all Aesthetix Callisto / Io Owners

John, when I was purchasing my Io, I asked Jim White what differences he heard between the standard Io and Io Signature, and with and without the second power supply option. His reply as to what he heard was very direct:

The Signature provides the following benefits:

.. Greater resolution
.. More neutral presentation
.. Improved high frequency extension and detail
.. Greater top to bottom coherency
.. Better bass definition

Adding the second supply improves the sound in the following ways:

.. Added space
.. Improved macro dynamics
.. Improved micro dynamics
.. Blacker backround
.. Greater ease to the sound, less strained

Move the volume control back and forth rapidly for about seconds. It's probably just some dust inside.

Thank you all for your comments:

Nkj: It's unfortunate that the PS's are pinned differently for the Io vs. Callisto. Must be a subtle difference needed between the two products. But that ends my chances of hearing either one at the moment with 2 PS's. But thank you for confirming that this could not be done. I am eager to learn what comes of your 1 vs. 2 PS for the Io signature listening session.

Rushton: Good descriptions as to what should be expected. When I changed all the Sovteks to Telefunkens in the Io, interesting that I did not gain any of the benefits that you listed with the Aesthetix upgrades. But what I did get was a much more full sound in the mids with incredible decay of notes and presence. The last ounce of sterility was gone. And this change alone caught my attention as it was so incredible. Otherwise the Io's sonics were pretty much the same with the stock tubes.

I feel I could use a more coherent tonal balance provided by a little more extension at the frequency extremes rather than an increase in dynamics and reduction in noise provided by the 2nd PS. So it looks like a change to the Sig would be the ticket for me with the Io if I decide to keep it vs. the soon to arrive Aria preamp.

Tabl10s: Right on! I guess I should have thought of this as I have read many times that other people have had to do this. But this was the first time I had a volume pot that did this. And sure enough, I rapidly moved the control back & forth for a good 10 seconds or so, with the unit powered off of course, and now the problem is gone. Super!

I am so spoiled with the silky smooth control on the BAT 31SE and it's awesome remote that handling these huge clunky controls on the Callisto will be a very big change to get used to. But already the Callisto has a much more authoritative presentation and more energy on the top vs. the BAT. It is most impressive with the CAT amps. But what surprises me here is how well the BAT competes with the Callisto Sig at double the price. There are clearly many very talented audio engineers out there.

Thanks again.

John

John,
I have a BAT VK-50SE, which I have been happy with for the price (having gone through many other units up to 2x the price). I am considering the Callisto but my main concern is the volume control. The BAT and other modern designs have many fine steps between mute and full output. How do you fine the volume control on the Callisto vs. the BAT? Ca you find levels suitable for quite listening? Is the range constant or with bigger steps at the low (greater attenuation) end? Finally, how quiet is it compared to the BAT? Thanks,
William

>"4: On the Callisto, when I move the "Right Level" control, there is a slight crackle/static sound from full attenuation to the first step and then again in the next 2-3 steps. From then on the noise is gone. I have swapped tubes between the L & R channels, swapped power cables between L & R, tried using a different set of inputs, swapping outputs to opposite amp inputs, etc. The problem stays with the right side. Does the right level control need to be "cleaned"?"

I asked Jim White about this and he said that the crackle/pop noise is normal.