QBG1 Professional Bass Preamp with EQ and DI

The QBG1 is our first product designed for the double bass. It is a preamp that was designed from the ground up to meet the requirements of acoustic double bass players, though it works equally as well for other lower register instruments, including electric bass. It has exceptional headroom, distortion and noise performance yet is small enough to mount almost invisibly under the tailpiece, where all controls are within easy reach.

Click on the images below for a larger view.

Front panel of QBG1 preamp

The QBG1 front panel contains all the frequently used controls. From left to right:

  • Volume control can fully mute the signal.
  • Phase switch can help fight undesirable interactions caused by your instrument and amplifier being out of phase.
  • The adjustable high pass filter cuts frequencies below those generated by the lowest string on your bass.
  • Bass, Mid and Treble tone controls provide up to 12 dB cut or boost as frequencies which actually are meaningful for bass instruments.
QBG1 Rear Panel

The QBG1 rear panel contains the input and outputs as well as less frequently used controls. From left to right:

  • Quarter-inch output jack. Plugging a standard mono cable into this jack also enables the power.
  • XLR balanced output (Direct Out). Allows the QBG1 to connect directly to a PA system or sound board.
  • Ground Lift switch can control hum caused by ground loop when the QBG1 is connected to both an amplifier using the quarter-inch output, and a PA or sound system using the XLR.
  • Phantom Power LED lights green when phantom power is provided to the QBG1.
  • Post/Pre switch selects the audio path to the XLR output. In the Pre position, only the gain is used. All other controls are bypassed, including the volume.
  • Impedance switch sets the input impedance to either 1 or 10 megohm.
  • Quarter-inch input can be used for pretty much any type of transducer, including magnetic and piezo.
Side panel of QBG1

The QBG1 side panel has the battery status and output overload LED as well as providing access to the input gain control. From left to right:

  • The red LED flashes briefly when a quarter inch cable is plugged into the output. It also flashes if the output signal is stronger than about +6 dBu. Finally, it is on continuously when the battery voltage drops too low.
  • The input gain can be adjusted from about -1 dB (no gain) to 20 dB using a small screwdriver. Once the gain has been set for the pickup you are using, you should never have to adjust it again.
Inside view od QBG1

Inside the QBG1 you'll find top quality components, including genuine Neutrik quarter-inch and XLR connectors and a professional-quality printed circuit board. No tools are required to access the battery compartment, simply unscrew the nuts from the input and output connectors and slide the top cover back.

Check out these specifications:

  • Small
Approximately 4.75” x 1.5” x 1.6”
  • Lightweight
Under 5 oz. including battery
  • Low distortion
Approximately 0.03% (1 kHz at -14 dBu)
  • High headroom
Approximately 13 dBu (1 kHz at 0.5% distortion)
  • Low noise
Approximately 10 microvolts, C-msg weighted (lowest gain)
  • Low power
Over 100 hours using a 9 V alkaline battery

The QBG1 has pretty much all the controls you need:

  • Adjustable input gain (-1 to +20 dB)
  • Volume control, with full mute capability
  • Adjustable high-pass filter to cut unwanted frequencies below those generated by your bottom string
  • 3-band equalizer optimized for the double bass
  • Phase reversal switch
  • Direct Out with 8 dBu of output capability into 600 ohms (1 kHz at 0.5% distortion)
  • Pre/Post EQ switch for Direct Out
  • 1 megohm / 10 megohm input impedance switch
  • Ground Lift switch

Compare the specifications and features of these preamps with any on the market. Value for money, I'm confident you can't do better!

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Canada Flag CAN$189