Amprx Power Solutions brought the new BrownBox ($250) amp-voltage regulator to Summer NAMM. It's essentially a Variac in a 3.7-pound aluminum enclosure. Whether you're looking for cranked-amp tones from your high-wattage amp at manageable volumes, or you're trying to get your low-wattage vintage combo working at period-correct voltages, the BrownBox lets you reduce voltage by 3, 4, 6, or 10 percent—but it also prevents you from accidentally lowering or increasing voltage to circuit- and tube-damaging levels.