I spent the better part of last weekend researching amps for a new pair of headphones. Reading other people's reviews and seeing their pics is fun, but figuring out whether the amp outputs enough power or if the damping factor is >= 8, well that's tedious. So what started as a few formulas on paper eventually (over the span of a week) turned into a website that calculates all this for you. It's a tool I built for myself, but I hope you'll find it useful too: www.audiobot9000.com