Powered amps for electric guitars have gotten some neat tricks powered by modern mobile tech over the years, but the new Positive Grid Spark ($299) might be the one that packs the most intelligence ...

Digital might be a four-letter word in the guitar world, but amp and effects emulation is nothing new; it's been around for some time and it's had a chance to get really good. Californian company ...

Easy to use. Clean, classic design. Sounds great and is reasonably loud. Affordable. Thousands of sound presets, play-alongs, and tips inside the Positive Grid app. Only eight hours of battery life.