You have acquired an unusual tool. The perfect combination of brutality and clarity, the Microtubes B3K delivers defined and powerful saturation in an intuitive format. There are no rules or limits, so dig in and unleash your tone.

Level Adjusts the volume of the overdriven signal.

Drive Adjusts the amount of saturation of the overdriven signal.

Blend Mixes the clean input signal with the overdriven signal. The clean signal remains at unity gain while the volume of the overdriven signal is adjusted by the Level knob, allowing precise control of the mixing ratio. Grunt Switch Adjusts the amount of low-frequency content to be overdriven by selecting between three different bass boost levels before the clipping stage. Attack Switch Adjusts the amount of treble content to be overdriven: The “Boost” setting emphasizes the clarity and presence of the treble content. The “Flat” position leaves this register intact while the “Cut” position reduces the amount of overdriven high frequencies. This new addition helps keep the treble part of the signal under control, especially useful when playing with new strings and/or speakers with tweeters! DIMENSIONS 11.3 × 7.5 cm (4.45 × 2.95 inches) CAUTION The Microtubes B3K has a current draw of 20 mA. Use only a regulated 9V DC adapter with a negative center tap. For ecological reasons, it does not accept batteries. Unregulated power supplies and/or higher voltages can result in suboptimal noise performance and even damage your unit, voiding the warranty.