SS. Amp to go well with Aesthetix Calypso Preamp.

The Theta Dreadnaught amplifier works very well with the Calypso. If you can find a 2-channel one it should fit your budget.

Here is an old thread. http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1141898495&read&keyw&zzaesthetix In it it is claimed that Jim at Aesthetix at one time did use Ayre equipment in conjunction with his own. There is an old thread about a compatibility problem with some of the older stuff, and then Charles Hansen (Ayre) chimes in and explains an old bug that has been eliminated. Anyway Ayre might end up on your short list, in which case this old thread may prove useful.

I participated in the old thread mentioned above by Mmike84. I can still say without hesitation that the Ayre amps are a great match with the Calypso. No more hum issues unless you happen on a older V5.
I can also say with a certainty that the Theta Dreadnaught I is a great match also (2 channel and hard to find.) It offers a little more power and a bigger bottom. If there is a weakness to the V5xe(if you want to call it that), it is that the bottom octave is a touch light. Imaging and depth is its strong suit.
The Ayre and Theta's are some of the best amps around for use with Vandersteen speakers if you want SS. Since I use Vandersteen's exclusively, I cannot speak to other speakers.
The sound of no negative feedback amps with time aligned speakers makes for one heck of a sonic presentation.
I really want to give Jim White's Atlas power amp a run since it falls into this camp also. May never happen though!

Not true Russb. Here is the quote from JA's "Measurements" section of the Calypso review.
"The balanced output impedance was 112 ohms at 1kHz and above, this increasing to 3900 ohms at 20Hz due to the finite physical size of the output coupling capacitors. The unbalanced output impedance was a high 2400 ohms at midrange and high frequencies, rising slightly to 3150 ohms at 20Hz. In unbalanced mode, the Calypso will need to be used with a power amplifier offering an input impedance of at least 30k ohms if the bass is not to sound lean."
The trouble with many tubed preamps is the output capacitor size is limited which results in an increase in output impedance at low frequencies. Based on my experience, I would recommend a ratio of at least 20:1 of the amp input impedance to the (maximum) preamp output impedance. However, if you do not have full range speakers, or are not concerned with a low bass roll-off then maybe this would not be an issue for you. I will say the Calypso did not do much for me when run into a McCormack DNA 500 (input impedance of 10K ohms).

The Innersound ESL-300 used should cost under 2K. It doesn't come up very often. Roger Sanders supports the brand. Works fine with my Aesthetix Janus (line stage of the Calypso).