Tube integrated with dac

I’m building a low cost bedroom system. I’ve just bought a fair of single driver full-range speakers, and want to pair them with a decent but low cost integrated amplifier, preferably with an USB DAC to be fed from my computer. I could also get a small USB DAC if a quality integrated is available without a built-in DAC. My budget is around $500 - $1000, new or used. What are some of the options?