I recently auditioned the JD-100 for 3 days and now have one on order. It added a new smoothness and midrange clarity to my system. I had not heard this type of pleasing reproduction from CD based playback before. For the price, its a really nice piece of equipment. I contacted the factory and learned that the stock tubes are Soltex 12AX7's. A tube upgrade could yield even a better unit. In my testing, I also used a power cord upgrade (PS Audio mini-lab). This provided a small enhancement to the detail and soundstage, compared to the stock PC. My only player comparison was with a Denon 2800 DVD/CD player, using D/A processing by a Class'e SSP-30. The noticeable differences in comparing the two players were, the JD-100 had increased sensitivity to bass, although this could the soltex tubes, vocals are much more 3D, and not as flat. The JD soundstage was more realistic, giving the presence of a live performance.