Music / Guitar Effects
Darkglass Electronics B7K Analog Bass Preamp User Guide
Quick guide for the Darkglass Electronics B7K Analog Bass Preamp, covering control functions, power requirements, technical specifications, and setup tips.
Table of contents
Quick guide from the manual
The Darkglass Electronics B7K is an analog bass preamp designed to provide tone-crushing overdrive while maintaining the instrument's original sound. This document provides essential information for proper operation, power requirements, and control adjustments.
Power requirements
Important: The B7K requires a regulated 9V DC adapter with a center-negative plug. The unit has a current draw of 30mA. Do not use batteries, as the device does not support them. Using unregulated power supplies or higher voltages may cause noise issues or damage the unit, which will void the warranty.
Controls
- Blend: Mixes the clean input signal with the overdriven signal. The clean signal remains at unity gain, while the Level knob controls the volume of the overdriven signal.
- Level: Sets the volume of the overdriven signal.
- Drive: Sets the amount of gain in the overdriven signal.
- Grunt Switch: Selects between three different bass boost levels before the clipping stage.
- Attack Switch: Adjusts treble saturation. Boost emphasizes treble clarity, Flat leaves the register untouched, and Cut reduces high-frequency saturation.
- EQ Controls: Low (+-12dB @ 100Hz), Low Mids (+-12dB @ 1kHz), Hi Mids (+-12dB @ 2.8kHz), Treble (+-12dB @ 5kHz).
Outputs
- Parallel Output: A hardwired copy of the input signal, ideal for clean signal recording or live setups.
- Direct Output: A balanced version of the 1/4 inch output, suitable for connecting to PA systems or studio mixing consoles.
Technical specifications
- Input Impedance: 500k
- Output Impedance: 1k
- Current Consumption: ~20mA
- Voltage: 9V DC (Center Negative)
- Dimensions: 106 mm x 120 mm x 45 mm
- Weight: 350 g
Practical help
Common problems
Noise or suboptimal performance
Ensure you are using a regulated 9V DC power supply. Unregulated supplies can cause significant noise.
Unit does not power on
Verify the power supply is 9V DC, center-negative, and provides at least 30mA. The unit does not accept batteries.
Interference with radio or TV
Reorient the receiving antenna, increase separation between the pedal and the receiver, or connect to a different circuit.
Before use
- Verify power supply is 9V DC, center-negative, and regulated.
- Ensure the power supply provides at least 30mA.
- Register your product at mypedal.darkglass.com using the serial number on the back of the pedal.
Specs in practice
- Input Impedance (500k)
- Standard high-impedance input suitable for passive and active bass pickups.
- Current Consumption (~20mA)
- The amount of power the pedal draws; ensure your power supply can handle at least 30mA.
- Parallel Output
- Provides a dry, unprocessed signal for parallel processing or clean recording.
Model compatibility
- Not compatible with batteries.
- Requires regulated 9V DC power only.
- Direct Output is balanced for professional audio equipment (PA/Mixing consoles).
Manual page author
Michael Turner
Technical manual editor
Reviews PDF manuals for structure, safety notes, and practical product details so readers can find the right information quickly.