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Open Box Gallien-Krueger Fusion 550 Hybrid Valve Bass Amplifier  

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The Gallien-Krueger Fusion 550 is GK's first bass amp head featuring an all-tube preamp. The Fusion 550 bass head incorporates a uniquely designed 6-stage tube preamp paired with a 500W version of the... Click To Read More About This Product


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The Gallien-Krueger Fusion 550 is GK's first bass amp head featuring an all-tube preamp. The Fusion 550 bass head incorporates a uniquely designed 6-stage tube preamp paired with a 500W version of the high-current solid-state power amp used in the GK 1001RB-II. The rich warmth of tubes, combined with the quick, punchy power that G-K bass amps are known for, is an aural experience you must hear to believe.

As if that wasn't enough, GK has inventively incorporated motorized knobs into the Fusion 550 head that allow you to store two different settings. This gives you the ability to dial in a separate overdrive or slap tone and footswitch between them--a first for a fully analog bass amplifier.

The Fusion 550 amp also features a simplified version of GK's exclusive 50-W 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 a tube driven 4-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. It also has a DI output which uses an isolated transformer for ultra-quiet operation.

  • Power Amp
  • 500-watt Class G high-current solidstate power amp
  • 50-watt Horn Bi-Amp System
  • Toroidal transformer
  • Pre Amp
  • Six-stage all tube preamp (three 12AX7's)
  • Motorized pots allow 2 presets
  • 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)
  • Dimensions:
    19"W x 5.25"H x 9.75"D
    Three rack spaces
    Weight: 24.5 lbs.

Pro Coverage gives you added warranty protection for your new gear. Stepping in where the manufacturer's "normal wear and tear" coverage ends, our Pro Coverage program offers you upgraded coverage if your product ever fails Read More.

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  • Free transfer of coverage to a new owner
  • Repair costs covered for up to three years from date of purchase
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  • Customer Reviews

Review Snapshot

by PowerReviews
Gallien-KruegerFusion 550 Hybrid Valve Bass Amplifier

(based on 3 reviews)

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Reviewed by 3 customers

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(2 of 4 customers found this review helpful)


Back to The Fusion 550

By Thomas Dougherty

from Hollywood Ca.

Comments about Gallien-Krueger Fusion 550 Hybrid Valve Bass Amplifier:

November 5th 1955, The sound was warm and the groove was strong. October 26th 1985, The Growl of the bass kicked it all night long. November 2013 and still going strong. Either sound or style of music you play can be dialed in with this Fantastic head. If you need the rich warm tube sound of a love song or groove to an R&B classic you're there. Or if you need that from the gutter Growl, Turn it up cause the solid state circuits will sizzle with sleeze. I have lived and played ALL styles of music and used many different rigs. If music is like air to you then this is one source of oxygen you can't do without.

(2 of 2 customers found this review helpful)



By Dave Nutzell

from Knoxville TN

Comments about Gallien-Krueger Fusion 550 Hybrid Valve Bass Amplifier:

I've owned this amp for 4 + years now, the longest I've owned any amp over the last 35 years. The famous "G-K growl" is here only in a smoother, more buttery version. Cool overdrive sounds too. There's meat for days all the way up the neck, your high notes won't run and hide, nor will those funky plucks that have a way of disappearing on many amps. The EQ is transparent and musical, though honestly I just set the thing flat and go with it. The dual tone thing is flawless, I do use that. This thing is LOUD, though it doesn't suffer when turned down. I really can't say enough good things about this amp, nor can I recommended it any more strongly. Buy one. You'll be happy!

(27 of 31 customers found this review helpful)


Incredible Amplifier

By Keith

from Boston, MA

Comments about Gallien-Krueger Fusion 550 Hybrid Valve Bass Amplifier:

Just got mine, running it through the new Neo 4x12 cabinet. Perfect match. The amp delivers extremely bright highs with heavy lows, so many tone options with the EQ and it all sounds really nice. Love the deep and Bright selectors, they completely enhance your high and low ends. Contour does a decent job shaping, Frequency selector is a great option with that feature. And this amp is way louder than I thought it would be. The only reason to even think about a Fusion 1050 is if your playing through 2 powerful cabs. This amp is LOUD. I encourage everyone to just try this amp out once. You'll be impressed. It's a keeper for me.

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