I can tell you straight away - Good choice! iDSD + Pan Am is really descent combo. While the built-in DAC in Pan Am is quite good (better than what you would get in your laptop), by upgrading to iDSD you get really neat sound. iDSD is a beautiful DAC, and it's solid state, then Pan Am adds this tube niceness and warmth of transistor output stage. You can get different results by setting iDSD volume knob at different levels. I use Sylvania tubes, and I really love them, but when input is 100% volume from iDSD it's slightly too tubey, so I turn Pan Am volume to 100% and I set 40% on iDSD, and I get really nice warm controlled sound. These two guys: Pan Am and iDSD - they seem like they were built for each other. And the Sylvania tubes is the best upgrade I got for my Pan Am. They not only sound great, but also glow beautifully in the dark (See photos I posted before).