Premier Guitar

7 Micro Bass Amp Heads for Any Budget

September 27, 2011
With the wave of tiny but powerful bass amps continuing to swell, bassists face a sea of opportunity amidst a plethora of features. This roundup is meant to serve as an intro to the possibilities out there and looks at a sampling of micro bass amps with varying sizes, weights, power ratings, and prices. The goal here is not to declare a winner or winners—at this level of amp, all are quality pieces of gear that differ mainly by their feature sets.

All of these amps accomplish their magic by using a class D amp design and a switching power supply. This approach eliminates bulky transformers that alone outweigh most of these amps. We’ve reviewed some micro bass amps in the past, including models from Carvin, SWR, TC Electronic, Ampeg, and Kustom, but this roundup brings you a new bumper crop of mighty midgets.

We used two basic parameters to guide our choices of amps to review. First, an amp had to weigh 5 pounds or less. And second, no single dimension of an amp could exceed 12 inches. We asked manufacturers to provide their smallest model that met these criteria, but allowed them to submit a higher-powered version if it met the required specs.

On the smallest end was the Gallien-Krueger MB200, weighing in at just 2 pounds, putting out 200 watts, and selling for $249. On the other end was the Genz-Benz Shuttle 9.0, coming in at 4 pounds, 900 watts, and at a cost of $829. Sitting in the middle were two micro bass amps in the 500-watt range, weights from 2 1/2 to 4 1/2 pounds, and selling between $500 and $700.

You’ll also find a chart that lets you compare the amps, ordered from lowest price to highest. Regardless of price, micro bass amps tend to have a more basic feature set with a 3-band or 4-band EQ and a direct out for plugging into a PA—there’s simply no place for a space-hogging, graphic EQ on the tiny front panel of these puppies.

Regardless of how little a micro bass amp weighs or how much power it puts out, your total rig weight will be dictated by your choice of speaker cabs. Although there are some lightweight cabs out there, none weigh as little as the amps. So if you’re looking for a rig that keeps the weight down, you should think modularly. For example, consider picking up a pair of cabs with neodymium speakers that weigh below 40 pounds, such as 1x12 or 2x10. Use one cab for rehearsals or small gigs, and add a second cab for louder settings. Of course, there’s nothing to stop you from pairing a 2 pound amp with a 150 pound, 8x10 cab, but once you’ve committed to that much cab weight, the size/weight savings of a micro bass amp probably doesn’t matter.

Micro bass amps are also useful when you have a rehearsal room or gig that provides speaker cabs, but you want to work with a familiar amp. Some of these amps can actually fit into a pocket of your gigbag for simple travel and hauling. However, most of these little guys have somewhat more delicate parts that will be better preserved with a separate case, either from the manufacturer or an off-the-rack bag designed for a computer or other portable electronics. For testing the amps, I used a P bass with fresh roundwound strings and a lightweight Euphonic Audio Wizzy cab with a 12" speaker. Because some of the amps had speakON connections and some had 1/4" jacks, I used a speaker cable with each type of connection on each end. To get familiar with the character of each unit, I first set all the EQ controls flat and played for awhile, then tweaked the features to check out the range of tones. While reading the specs in the manuals, just to be sure I understood how to use each amp and its features correctly, I revisited each amp several times.

OK then, time to take a look at the amps from smallest to largest.

The first four can be described as our micro-est of the micros, each in the 200-watt power range and most selling for roughly $300 or less. At this power range, you should be able to comfortably cover rehearsals and smaller gigs, depending on the size, efficiency, and impedance of your speaker cabs.
Our micros in the middle push out power around 500 watts RMS and sell in the mid to upper $600 range, although not necessarily possessing more features. At this level of power, you should be able to cut nearly any gig with the right combination of speaker cabs.
Finally, we look at one little big gun micro-amp, which provides the power of a full-size rig in a portable package.
We've also broken down the features and size into a handy chart at the end of this article. Without further ado, here's the roundup...

Gallien Krueger MB200
The tiniest of the bunch is the Gallien-Krueger MB200. This sturdy little beast is housed in a silver metal box with meaty rubber feet. Picking up on the look of the rest of the GK line, the MB200 even sports micro metal handles on the front, a nice touch for carrying it around (even with one finger!) and providing protection for the five knobs and two toggle switches on its face. Each of the knobs has a bright white line on the front and top, making settings easy to check at a glance.

Also picking up on GK traditions, the MB200 incorporates the GK 4-band EQ section. And like their other models, the treble is on the left with the bass on the right. One toggle switch pads the input for especially hot basses and the other selects a preset contour EQ that scoops the mids, while boosting the treble and bass. The left side of the amp’s case has a whisper-quiet variable speed fan. On the back, the DI’s XLR jack has a Pre/Post switch, allowing you to send your signal to the board with or without EQ. There’s 1/4" jack for headphones that doubles as a line out and has a switch that selects the line-level output or engages the headphone-level output. A handy 1/8" jack is also onboard to add an MP3 player for play-along practicing.

Tone-wise, I thought the MB200 was solid and punchy—plenty loud for practicing, rehearsals, and small gigs. The tone was both fat and clear, and the EQ section allowed for ample tonal variations. The Contour switch (similar to the mid cut on their RB series by emulating the sound achieved when turning the variable contour control all the way up) scooped out quite a bit of the midrange, working well for slap playing, but a little murky for all-around sound. In all, the MB200 is a helpful tool when you need good sound while traveling light—and at $249 on the street, it’s very affordable. If you’re looking for a micro with more features and more power, GK also has a pair of somewhat larger (though still meeting the criteria for our roundup) micros to suit your needs—the MB500 and the MB Fusion, which has three preamp tubes and two switchable channels.

Street $249

Overtōn Flyweight 200
Overtōn is a new, Chicago-based company and the bright-red, anodized case of their Flyweight 200 looks like no other. While the six front-panel knobs are sturdy and functional, the dots that indicate settings are a little on the small side. Overtōn took a different approach to its controls, with Mute, Compressor, and Sculpt controlled by momentary contact switches on the Gain, Sculpt, and Bass EQ knobs, respectively. Each switch has a small indicator light below it to show whether it’s on or off. The compressor is completely pre-set, just in or out, but was unobtrusive during my playing tests.

At first, I expected the Sculpt control to be like an enhance or contour control found on most contemporary bass amps, where their job is to scoop out the mids and bump up the highs and lows. Overton’s Sculpt, in contrast, seems to make the tone both fatter and more aggressive in the mids when turning the control up, making it a useful and signature feature of the Flyweight 200.

On the back panel, the Flyweight 200 includes a DI with both level adjustment and ground lift, along with a pair of speaker jacks that will accommodate either a speakON or 1/4" cable. Along the bottom lives a series of 1/4" jacks for aux in, effects send/return, tuner out, headphones out, and even a footswitch jack for on-the-fly adjustments.

I would describe the tone of the Flyweight 200 as articulate, natural, and versatile. A turn of the Sculpt control provides a good range of sounds, which can be further tweaked via the 3-band EQ, and the separate Gain and Master Volume controls allow even more tonal variations. With a street price of $229, the feature-packed Flyweight 200 is a real bargain.

Street $229

Carvin BX250 Micro Bass
Carvin’s BX250 Micro Bass is a tad larger in this group, but delivers a strong feature set. The front panel is decked out with two rows of controls—seven knobs and two switches on the top row, and four knobs and two switches in the second row.

Carvin came up with something a bit different on the front end. Usually, the first knob on a bass amp is the gain, which tweaks how hot the signal gets when pushed into the rest of the preamp. Turning fully down provides zero gain on most amps, but Carvin’s Drive control can be turned all the way down to achieve a more natural tone or turned up to create a more aggressive sound—with an additional level gain. Likewise, the variable Contour control can go from a flat EQ to one that’s quite scooped. A nice feature of the EQ section are two bands of semi-parametric midrange that allow you to adjust the center points from 50 Hz to 500 Hz and 200 Hz to 2000 Hz.

The front panel of the BX250 also includes an input pad for active basses, a Mute switch, and an adjustable Compressor knob. I found the Compressor control could get my tone squishy quite easily—a little went a long way. Though it’s a little unusual to find all the DI controls on an amp’s front panel, the BX250 includes all three key adjustments there with ground lift, pre/post select, and level. This makes for a clean rear panel with just a DI XLR jack, phones/tuner jack, and two 1/4" speaker outs. The front panel has a handy pair of metal U-handles for easy carrying that have plenty of space for two or three fingers.

It took me a little while to understand the contribution of the Drive control to the sound of the BX250 Micro Bass, but once I got the hang of it, I could easily go from natural to quite aggressive and beefy with just a little tweaking of the Drive and Contour, along with some fine-tuning of the EQ. At $299 plus $19 shipping direct from Carvin, the BX250 is a little pricier than the other two micro-micros, but if the feature set has what you’re after, it could turn out to be a truly handy piece of gear.

Street $299

Eden WTX-264
Eden’s WTX-264 straddles the region between the micro-micros and our pair of micros in the middle. Like the others in the first group, its power is in the 200-plus range, delivering 260 to 300 watts. Like the middle group, the WTX-264 has a few more features, and a price ($449) that goes with them. The front panel of the WRX-264 is filled with knobs and jacks, with six knobs across the top and six jacks (and a Mute switch) right below. The gold-toned front and rear panels, black knurled knobs, flat-black metal jacks, and backlit Eden logo gives it the look and feel of old-school audiophile equipment. Eden’s trademark Enhance control is included on this unit—working much like a contour control on other amps—boosting the highs and lows while cutting the mids. And Eden’s controls are like hot sauce, with a little going a long way.

The WTX-264 uses what Eden calls a “unique, class D power module” that can run off of any power rating you might find—110 or 220 volts, 50 or 60 cycles. Just unplug one power cord, pop in another and you’re ready to go, right off the plane. On the back, you’ll find both a speakON jack and a pair of 1/4" output jacks.

While playing my P bass through the WTX-264, the sound was present, warm, and authoritative. This little amp provided solid punch, yet didn’t get boomy. Likewise, dialing in a bit of Enhance warmed things up without adding any mud. The Bass Boost control on the WTX-264 is a bit unusual, somewhat like the loudness control on some home sound systems that bumps up the lows at low-volume settings, but backs them off when things get louder. Likewise, the Mid Shift control serves double-duty, with a center at either 550 Hz for warm mids or 2.2 kHz for a more present tone. For a price of $449, the WTX-264 offers a voice of its own in a small, sturdy package.

Street $449

Euphonic Audio Micro
The Euphonic Audio Micro is designed for both electric and acoustic bassists, with each of its two channels tweaked for one or the other. Channel 1 is designed for electric bass, with a midrange center-frequency of 500 Hz. Channel 2 is for acoustic bass, with a midrange center at 800 Hz and a variable, high-pass filter that trims the low end rumble that the big basses tend to put out with their piezo pickups. Each channel has simple Low, Mid, and High EQ controls with cut and boost on each.

A momentary-contact switch by the input jacks toggles between the two channels, which helps simplify doubling at a gig. If only one bass is plugged in, the switch toggles the EQ between the two channels, allowing one tone for playing the foundation, and another that can be dialed in for soloing.

The Micro is not voiced toward a scooped EQ, but instead sounds more neutral. It’s something that might require a little getting used to for electric bass, but sounds right at home on acoustic. In either case, there is enough EQ range to dial in whatever you are after. At first glance, the Micro’s DI looks like a standard 1/4" line out jack, but the manual clarifies that the DI jack is a tip-ring-sleeve, balanced out. This allows a breakout cable to convert from a TRS plug to the usual XLR that’s found on most bass amps. Finally, there’s a handy Mute button on the front that defaults to muting your sound when powering up—very convenient for avoiding stray notes as you get started.

At $675, this amp provides plenty of power, the handy dual-channel EQ capability, and one of the smallest footprints you’re likely to come across.

Street $675

Markbass F1
Markbass products can be spotted right away with their black and yellow color scheme, and even though the F1 amp is less than two inches in height, those colors make this micro stand out. With that slight of a dimension, the front panel looks like a solid row of knobs which encompass the same EQ system found on the other Markbass heads—four bands of EQ along with VLE, VPF, Gain, and Master controls.

VLE stands for Vintage Loudspeaker Emulator, a knob that cuts high end to create a bass tone headed toward the good old days, when a 2x15 cab—sans tweeter—was likely to be found on many bandstands. VPF, in contrast, stands for Variable Pre-shape Filter and is used to dial in a scooped sound that’s better fit to rockers and slappers.

On the back, you’ll find a pair of combo output jacks that take either 1/4" or speakON speaker cables. With all that Markbass was able to fit on the front and back panels, it seems that they ran out of space to squeeze in a Mute switch and DI level control. Not to worry if those features are a must for you—their F500 amp includes them as well as two bands of semi-parametric mids. And it has a profile that still fits the size and weight parameters of this roundup.

Giving this head some playing time, I quickly recognized the big, punchy, low-end voice that is characteristic of their popular Little Mark series, but with a little more presence. With no EQ dialed in, the F1 brings out a warm tone. Utilizing the 4-band EQ and the VLE or VPF controls, it’s easy to dial in a wide-ranging tonal palette. The Markbass F1 will set you back a bit more cash ($650) than some other amps on the market, but in return, you’ll get a big sound and a lot of versatility in a durable and easily to haul package.

Street $650

Genz-Benz Shuttle 9.0
If you like the idea of a micro bass amp and want the oomph of a big rig, the Genz-Benz Shuttle 9.0 should fit the bill nicely. Although a micro amp in terms of size and weight, the Shuttle 9.0 packs a serious wallop with 900 watts RMS and a bevy of sound-shaping features, including a 12AX7 preamp tube with variable gain and output level. The seven, metal knobs on the Shuttle’s front panel are knurled and sturdy, and while the indicator dots are black and don’t stand out particularly well, there are helpful notches above the dots. There are also four, metal push-buttons that handle the muting function and EQ pre-shaping.

The front panel of the Shuttle 9.0 is nicely organized into four, well-labeled sections. The Tube Preamp section, which includes the Mute button, allows for overdriving the preamp tube (or not) while also managing the signal level it sends to the EQ section. Although the EQ setup is the basic, 3-band arrangement, the added semi-parametric control provides a generous sweep of center frequencies that nearly spans the gap between the high and low bands. The Signal Shape section includes three pre-shapes—a bass boost, a mid scoop, and a high boost—that can also be controlled by a Genz-Benz 4-button foot switch. Finally, the Master Section not only wrangles the final volume level, but also offers a platoon of status indicator lights to help you see what’s going on while you play.

Flipping around to the back of the Shuttle 9.0 unveils plenty more features. Rather than automatically detecting 110 or 220 voltages, there’s a bright red switch that toggles between the two. A pair of speakON jacks handles the speaker connection duties. There are also the usual effects loop jacks, an aux in, and tuner out. The DI includes three small switches for ground lift, pre/post EQ send, and DI output level (line or mic), which is a handy way to send the right signal to the board.

In all, my experience playing through the Shuttle 9.0 found punch, focus, and authority without being overly aggressive. Between the tube section, 3-band EQ, and three pre-shapes, this amp provides a versatile array of sounds that will cover nearly any musical venue you might be facing. If you don’t need this much power and want to save a little money from the $829 price tag, Genz-Benz also manufactures the Shuttle in 300- and 600-watt models with essentially the same feature set.

Street $829

Rounding Up the Roundup
So there you have it, an introduction to seven micro bass amps, ranging from tiny-but-formidable to small-and-mighty. Likewise, the more budget-conscious of the lot check out below $300, while the higher wattage and feature-heavy models go for $600 or more. In every case, the size of these micros belies their features, capabilities, and tone by providing a bass sound that used to take 20 or 30 pounds and three or four times the footprint.

Although we covered a good number of micro bass amps here, there are many more great options on the market that churn out big tone in a tiny package. If you’re the kind of bassist who thinks that size matters, but that bigger doesn’t necessarily mean better, it could be that a micro bass amp would be a good fit for your needs.

Here's a handy cheat-sheet of the features, pricing, and size of the amps in this roundup:

Power at 4 Ω
EQ Controls
Genz-Benz Shuttle 9.0
900 watts
Ground lift, Pre/Post, mic/line levels
Low/parametric Mid/ parametric Mid Freq/High/three preshapes 2.5"x10"x10.5"
4 pounds
Tube gain control, effects loop, aux in, tuner out, phones out, multi-function status display, 100-240 volt operation
Euphonic Audio Micro 550 watts $675
TRS, requires cable, level
2.3 pounds
2 channels w/EQ, channel switching, high-pass filter, effects loop/tuner out, footswitch jack
Markbass F1
500 watts $650
Ground lift
Low/Mid Low/Mid High/High
4.6 pounds
VPF (Variable Pre-shape Filter), VLE (Vintage Loudspeaker Emulator)
Eden WTX-264
260-300 watts $449
Ground lift, level
Bass/Mid/High/Mid Shift/ Bass Boost
4.3 pounds
Mute, effects loop, tuner out, aux in, phones out, 100-240 volt operation
Carvin BX250 Micro Bass 250 watts $299
Ground lift, Pre/Post, level Bass/parametric Lo Mid/parametric Hi-Mid/Treble/Contour
3.2 pounds
Compressor, Drive, mute, phones/tuner out, 90-240 volt operation
Gallien-Krueger MB200
200 watts $249
Pre/Post Treble/Hi-Mid/Lo-Mid/Bass/Contour 1.75"x7.75"x8"
2 pounds
Aux in, line/phones out
Overtōn Featherweight 200
200 watts $229
Ground lift, level
2.1 pounds
Aux in, effects loop, tuner out, phones out, switchable compressor