B&W P9 Signature: Amazing sound with a hefty price

As you move towards the high-end spectrum of hi-fi, features on gadgets typically disappear. It's not uncommon to see a power amplifier, priced like a family car, with a single button, while amps that cost a few hundred bucks come with a bazillion knobs and switches. The idea is that everything that's not strictly necessary just gets in the way of that perfect sound — and perfect sound is the ultimate goal of expensive hi-fi equipment.  It's no wonder, then that B&W's latest pair