A decade ago musicians were often measured by the size of their stacks. If a guy had two 100watt Marshall heads and four cabinets, he had to be good, right? Right. So what’s the deal with these tiny amps that keep popping up behind musicians on video broadcasts, in recording studios and on live gigs? Why have a lot of players traded off their big rigs for these dinky little critters that are so small they can be carried in a VW?