The Darkglass Electronics Microtubes B7K Ultra packs all of the bass-centric overdriven goodness of its standard predecessor with a host of new features to take your tone to the next level. Retaining the four-band onboard EQ and the Grunt four-way switch which emphasizes different frequencies in the low-end, the Ultra version includes new features like a dedicated footswitch for engaging the overdrive separately and a whopping six mid-frequency positions for truly sculpted bass tone.