Congratulations on a fine product. I have my DAC+ Pro hooked up to a recently built Dynaco ST-70 tube amp. These tube amps are very picky about the pre-amp used for a source. I have tried many pre-amps with the Dynaco, and the DAC+ Pro is the best, by far. Sound stage is superb, and it plays my 24-192 Flac files flawlessly. My audiophile buddies are quite shocked when they hear a $50 DAC, outperform a $700 preamp!