What preamp

Hello

I had been an Audiogon member for a while now and I need help deciding what preamp to buy, Things had been a bit difficult money wise, but I'm an audio enthusiast and I'm trying to put together a decent stereo system. The speaker are Polk Audio RTi-A9 the amp is going to be Emotiva XPA-2 . I'm looking for something to match the amp and speakers, I would like to have something to calm down the bit brightness of the Pollk Audio RT's that I've had heard they have. I'm also looking for balanced out connection aka XLR. All recommendation are always welcome. Thank you

Armando