Krell's $15k Illusion and $7k Illusion II preamplifers may look the similar, but they are completely different. The Illusion is an all-analog solution that breaks the power supply into a separate box. It has proprietary connections so, if you have all Krell gear, you can realize sonic benefits you didn't know you needed. The Illusion II has digital connections, a headphone output (no, the Illusion flagship doesn't have a headphone output), and no ability to add an internal crossover for your subs. We find some of their design choices odd but, then again, they've been at this a long time. Surely they know their customers. Discuss "Krell Illusion and Illusion II Stereo Preamplifiers Preview" here. Read the article.