Hands-On Review:Gallien–Krueger Micro Bass Heads
Compact heads deliver high performance at affordable prices
By By Terry Buddingh
International Music-Gear Journalist
Gallien-Krueger has consistently been on the leading edge of bass amp design and technology for more than 40 years, and that decades-long tradition continues with the ultra-compact, ultra-lightweight, full-featured, and super-affordable MB series heads. Featuring state-of-the-art Class D power amps, these surprisingly powerful micro-sized heads offer effortless portability and a full complement of essential features—all at amazingly affordable prices.
Theand boast GK's time-tested and gig-proven solid-state preamp and tone control circuitry, while the borrows its all-tube preamp from GK's heavyweight hybrid Fusion 550 (but without the Fusion 550's programmable, motorized tone controls). Built to endure the rigors of the road, these serious tone machines fully embody Bob Gallien's "tools, not toys" design philosophy, and all three heads are loaded with essential modern-day real-world gigging accouterments like balanced XLR DI outputs and combination 1/4" to Speakon speaker output jacks.
Theis amazingly small; it's smaller than many DI boxes, standalone preamps, and pedals, and it's thin enough to slip easily into most gig bag pockets. Weighing a mere 2 pounds, it's difficult to imagine a more travel-friendly bass head. Despite its small size, GK still managed to include everything a gigging bass player needs: there's a -10dB pad switch to accommodate high-output active basses, an on/off switch for GK's classic Contour pre-shape circuit, plus GK's legendary 4-band tone control section. The MB200 also has a balanced DI output with pre/post EQ selector button; a 1/8" auxiliary input for CD, MP3, or other players; and a switchable line-out/headphone jack. The MB200 has a single 1/4" to Speakon combo jack.
It may look tiny, but theis indeed a serious—and versatile—tone tool. Conservatively rated at 200W @ 4 ohms, the MB200 is surprisingly loud, with amazingly strong and weighty low-end response. It looks small, but it sounds massive. The MB200 is bound to find its way into to a wide range of applications. You could use it as a full-featured DI box, enhancing your sound with GK's excellent sounding Contour and tone controls, or you could use the Line Out to drive a large power amp when extra volume might be required. I'm sure these pint-sized powerhouses will find their way into guitar, keyboard, and other applications as well. Considering its effortless portability, gig-worthy power, potential for adaptability, and affordable price, the MB200 will surely find a place in even the most extensive bass gear arsenals. This is a real no-brainer—everybody should have an MB200.
With its Mute button, Effects Loop, Tuner Output, defeatable Limiter, Master Volume control, and footswitchable Boost with secondary Master Volume control, theoffers a boatload of additional features to go along with its extra power. With an honest 500W @ 4 ohms, the MB500 kicks like a mule with an authoritative and forceful punch. This head likes to rock and rock hard; it really comes to life when you crank it up, and it seems to dare you to do so. Weighing-in at 3.75 pounds, and breaking the buck-a-watt price barrier, the MB500 packs a lot of value into an incredibly portable high-power package.
The footswitchable Boost feature greatly expands the's range of tonal options. Increasing the Boost knob setting increases the trademark GK growl, and this added texture provides some colorful contrast when switching from a cleaner, non-boosted setting. It's useful for more rock-flavored tone, soloing, or contrasting mid-song section and textural changes.
The post-EQ, pre-Boost Effects Loop works great with a wide range of devices, and greatly expands the's range of options. The MB500 has two combination 1/4" to Speakon speaker output jacks, so it can easily power two speaker cabinets.
Thegrafts an all-tube preamp onto the same power amp section used in the , so the power is the same: 500W @ 4 ohms. Using three 12AX7 tubes running at high voltage, the MB Fusion's preamp is essentially a tube-driven adaptation of GK's classic solid state preamp circuit design. The feature set is similar to the MB500, except the MB Fusion has selectable Contour control mid-dip center frequencies (500Hz or 800Hz), and separate switches labeled Presence and Deep (for a 4dB boost @ 10kHz and 30Hz, respectively).
Thehas two footswitchable Gain and Master volume controls. These allow you to instantly switch between two flavors of tube overdrive (or clean tones) with the tap of a switch. Like the , the MB Fusion is capable of a wide range of tones and textures. The MB Fusion's cleaner tones impart a delectable sense of hi-fi sweetness, texture, dimension, and dynamic nuance that tube lovers will surely recognize and enjoy. Using a pick and cranking up the Gain knob elicits wicked grind and growl that clearly evokes the textures of far less portable all-tube bass icons.
Features & Specs
- • Passive and active switches
- • Preamp Gain control
- • Contour control (on/off button on )
- • Active 4-band tone controls
- • Balanced XLR DI output jack
- • State-of-the-art Class D power amp
- • Weight-reducing switch-mode power supply
- • Combination 1/4" and Speakon speaker output jacks
- • 200W @ 4 ohms
- • 140W @ 8 ohms
- • 7.75" x 8" x 1.75"
- • 2 lb.
- • 500W @ 4 ohms
- • 350W @ 8 ohms
- • 11" x 9" x 1.75"
- • 3.75 lb.
- • All-tube preamp
- • 500W @ 4 ohms
- • 350W @ 8 ohms
- • 11" x 9.75" x 1.75"
- • 4.5 lb.
GK's compact yet featured-packedoffer gig-worthy power and tone in surprisingly lightweight and exceptionally high-value packages. Click or call now to order with the assurance of Musician's Friend's Dual Guarantees that ensure your total satisfaction and the lowest price.