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Darkglass Electronics Microtubes B7K V2

Darkglass Microtubes B7K Version 2 Analog Bass Preamp

Darkglass Electronics Microtubes B7K V2: Analog Bass Preamp for the Modern Bassist

The Darkglass Microtubes B7K Version 2 Analog Bass Preamp combines a powerful overdrive circuit with comprehensive EQ and flexible connectivity options, making it an essential tool for the modern bassist. Known for its high-quality components and versatile tonal shaping capabilities, the Microtubes B7K V2 provides unparalleled control over your bass sound.



Mixes the clean input signal with the overdriven signal. The clean signal remains at unity gain while the volume of the overdriven signal is set by the Level knob, allowing for fine control of the blend ratio.


Sets the volume of the overdriven signal, enabling you to balance the overdrive with your clean tone.


Adjusts the amount of saturation in the overdriven signal, giving you everything from subtle warmth to aggressive distortion.

Grunt Switch

Controls the amount of low-frequency content to saturate by selecting between three different bass boost levels before the clipping stage, enhancing the low-end response.

Attack Switch

Sets the amount of treble content to saturate:

  • Boost: Emphasizes the treble content for extra clarity and presence.
  • Flat: Leaves the treble frequencies untouched.
  • Cut: Reduces the high frequencies being saturated for a smoother tone.

EQ Controls

  • Low: +/-12dB @ 100Hz
  • Low Mids: +/-12dB @ 500Hz or 1kHz (selectable with Low Mids Switch)
  • Hi Mids: +/-12dB @ 1.5kHz or 3kHz (selectable with Hi Mids Switch)
  • Treble: +/-12dB @ 5kHz


  • Parallel Output: A passthrough for your input signal, useful for parallel processing.
  • Direct Output: A balanced version of the output, ideal for running into PAs or studio mixing consoles.


  • Dimensions: 4.72 x 4.21 inches (12 x 10.7 cm)
  • Current Draw: 30mA
  • Power Requirements: Regulated 9V DC adapter with a center-negative plug (batteries not supported)


The Microtubes B7K V2 has a current draw of 30mA. Only use a regulated 9V DC adapter with a center-negative plug. Unregulated power supplies and/or higher voltages may result in suboptimal noise performance and even damage your unit, voiding the warranty.

In the interest of continuous improvement, specifications are subject to change without notice. For more information, visit Darkglass Electronics.


The manufacturer claims that the product fulfills the requirements as set by EN55013, EN55020, EN60555-2, EN60555-3, RoHS, and WEEE.

Enhance your bass sound with the Darkglass Microtubes B7K V2, a versatile and powerful preamp that offers exceptional control and tonal flexibility.

This pedal ships fully insured with signature required.