“If you’ve ever wondered what unobtanium looks like in amp form, this is it”: Played and revered by Stevie Ray Vaughan, Carlos Santana, and John Mayer, Dumble amps have an almost mythical reputation. But what's all the fuss really about?

“If you’ve ever wondered what unobtanium looks like in amp form, this is it”: Played and revered by Stevie Ray Vaughan, Carlos Santana, and John Mayer, Dumble amps have an almost mythical reputation. But what's all the fuss really about?

The late Alexander Dumble built only a handful of meticulously crafted, much-sought-after amplifiers every year – and they ended up in the backlines of many of the greatest guitarists of all time. So where exactly did the magic come from?