used Integrated tube amp under $1500 for Klipsch Cornwall III's?

With very efficient speakers,

there are a few McIntosh Pre-amps with enough power to drive speakers directly. 

This McIntosh C26 Pre-amp has a 10wpc amp, main and/or remote speaker terminals and face mounted push button selectors for those outputs. It could drive the Klipsch speakers directly.

One advantage is of course sending pre-amp out to an amp for main speakers, and driving a set of efficient remote speakers directly from the C26.

In any case, it is a terrific preamp, here's a listing that shows it well.

https://www.ebay.com/itm/Mcintosh-Preamplifier-C26/254293553227?hash=item3b3513b04b:g:v6wAAOSwDOZdJ306

Opps, I forgot it's a solid state preamp, you want tubes, as do I. Oh well, it's fun to know about I think

I’m sure there are many great choices. I have the CW lll as well. I love vintage tube gear but with went with a Primaluna and very happy with the listening experience. The self biasing makes rolling tubes a breeze. Currently going with Jan GE 6550’s and Yugo 12au7’s in the pre. 

Like was mentioned above,  I have used HH scott model 222 and it works beautifully! Yes I  did the restoration myself so it saved me a few bucks! It came out very good. Used it with a pair of LA Scalas.