Try a Cary SLP-50B. With $1500 to spend, you can buy the preamp, upgrade the tubes, and upgrade the power cable. They are excellent little preamps and you can generally find one used for about half of the $1500 you have allowed yourself. You might even have enough left over for a couple of other little goodies.
Need a good used tube pre $1500 or less
The only experience I have had was with an AR LS5mkIII. It is long gone. I no longer need balanced. For the most part I will use it for nothing more than to control volume. Any recommendations including you opinion of the sound characteristics would be welcomed.