7B³ mono amplifiers are truly special. Though they don't look much different, they're a big step up from the venerable 4B³. The power supply for this amplifier is built around a specially wound transformer that is substantially more efficient than normal. With twice the power available, they can drive all but the most brutal loads to lifelike levels. But even at whisper quiet levels, they reveal detail and nuance in your recordings that you never knew existed until now.