@asp307 I have used the Delos on my XP-15 for several years. I settled on a 250 ohm load but honestly anything between 100 and 1000 sounded fine with that combo. I always have used the balanced outputs to the line preamp. The XP-15 is a very well behaved phono pre. It allows you to hear the differences in a wide variety of cartridges and tonearms.