Gallien-Krueger Debuts Fusion 550 Bass Head With All-Tube Preamp

Gallien-Krueger introduces its first bass head featuring an all tube preamp.
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The Fusion 550 bass head incorporates a uniquely designed six stage tube preamp paired with a 500 watt version of the high current solid state power amp used in the 1001RB-II. The rich warmth of tubes is combined with the quick, punchy power that GK bass amps are known for.

GK also incorporates motorized knobs which allow you to store two different settings. This gives you the ability to dial in a separate overdriven or slap tone and footswitch between them, a first for a fully analog bass amplifier. The Fusion 550 also features a simplified version of GK's exclusive 50 watt Horn Bi-Amp System. Dial in the horn where you like it and as you adjust your volume with the master control the ratio between the woofer and tweeter is preserved.

Other features include tube driven four band active EQ and voicing filters with a frequency select for the contour control. The rear panel features include Neutrik Speakon and 1/4" speaker output jacks, effects loop, tuner out, and a footswitch input jack. Also on the rear panel is a DI output which uses an isolated transformer for ultra-quiet operation. The Fusion 550 should begin appearing in stores around June 2006.

Power Amp:

  • 500 watt Class G solid-state power amp
  • 50 watt Horn Bi-Amp System
  • Toroidal transformer

Pre Amp:

  • Six stage all tube preamp (three 12AX7's)
  • Footswitchable two channel motorized gain, master and horn level controls
  • Tube driven four band active EQ
  • Contour control with 500hZ-800hZ mid frequency select
  • Deep and bright switch
  • Mute switch
  • 1/4" input jack with active/passive switch (-14dB)

Rear Panel:

  • Effects loop & tuner output
  • Active DI with level control, pre/post and ground switch
  • Two Horn Bi-Amp compatible Speakon outputs
  • Two 1/4" speaker outputs (fullrange only)
  • Rear-vented temperature controlled fan


  • 19" Wide x 5.25" tall x 9.75" deep
  • Three rack spaces

For more information, visit their web site at