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Posted by Doug Young

Acoustic guitarists usually depend on effects much less than electric players, but given the chance, the list of devices we might wish to use can be fairly long. String together a preamp, DI, EQ, tuners, and footswitches for muting and boosting, reverb, chorus, delay, modeler, and a few more and before you know it you’ll have an acoustic pedal board that rivals those of its electric cousins. Or you could have all of those in a single small pedal, which is what Zoom has tried to provide with its latest acoustic preamp and effects unit, the A3.

Zoom is a Japanese company with a long history of turning out impressive and useful devices for musicians, including handheld audio and video recorders, guitar stompboxes, multitrack recorders, and more. Its A2 multi-effects pedal is popular with acoustic guitarists, and Zoom has packed even more functionality into the new A3.

Small and Powerful

Zoom-A3At just 4 1/4 inches wide and 6 inches long, the Zoom A3 is small enough to fit in the accessory compartment of most guitar cases, but Zoom has still managed to pack in a lot of functionality. You get a rough sense of the device’s complexity just from looking at the controls. The top of the A3 includes three footswitches (Effect On/Off, Volume Boost, and Anti-Feedback), 14 other controls, and a small LED screen. The controls fall into several categories. Three knobs cover EQ: Bass, Midrange, and Treble. Two provide level adjustments for the separate Mic and Pickup inputs. Another pair provides balance between dry and effected signals and master volume. Three more controls serve double duty as both knobs and pushable switches and are used to navigate the LED screen. There are also three LEDs that serve as both status indicators and pushable buttons that let you control a related setting. The final control allows you to select the body type of the guitar you are using, to allow the modeling features to work optimally.

The A3 also includes stereo 1/4-inch outputs and a 1/4-inch mono input jack for a pickup, along with a switch that allows you to choose settings to complement your pickup: flat, magnetic, or piezo. The manual does not state exactly what these switches do, and I found the effect to be extremely subtle. It appears that the Magnetic switch boosts the bass a bit, while the Piezo position rolls off some highs. The manual specs the input impedance at a constant 1 Megohm. The back of the unit contains an XLR mic input (24 or 48 volts of phantom power can be selected via software), a jack for using a nine-volt power adaptor (the unit can also be powered via USB), a Ground-Lift switch, and an XLR DI out.

Software Effects and Controls

The A3’s hardware features are impressive enough, but its real power lies in the software, accessed via the LED screen and controlled by three combination push-button/knobs. The LED screen presents a virtual pedal board with three slots. Slot one is always occupied by the modeler, which we’ll explore in a minute. The other two slots can be loaded with any two of a large collection of effects, which include reverbs, delays, chorus, phaser, flanger, compressors, auto-wah, exciters, and graphic and parametric EQs. Pushing the buttons steps through the available effects, while turning them takes you inside the controls of the selected effect. Patches can be saved to memory so you can recall different selections as you need them.


Exploring the effects could take a long time, and there is certainly something here for everyone. I quickly found some subtle chorus sounds I especially liked. Overall, the effect quality is on par with other stompbox effects, but the sheer number and tweakability makes it very likely that you can fine-tune one to get a sound you like. With 12 reverb algorithms alone, there are nearly endless options.

Extensive Modeling Possibilities

With all of the effects and features, it’s easy to forget one of the most powerful features of the A3: a full-featured modeler. The modeling is easy to use. First you select the type of guitar you are using with the Body-Type selectorknob on top, and your pickup type from a selector on the side. The body selector provides 16 guitar types to choose from, including nylon-string, OM, dreadnought, and even upright bass. Once you have configured the A3 for the type if guitar and pickup you are using, you can choose one of 36 model typesfrom a software menu to alter the way the A3 transforms your sound. So, at least in theory, you can set up the Zoom A3 to match your Martin OM with an undersaddle pickup, and then make it sound like a Gibson J-200 by choosing the appropriate model.

Test Drive

With all of the features included in this complex unit, it was hard to know where to begin in checking it out, so I began with the basics. You can easily ignore all of the exotic features and just plug in a guitar, run the unbalanced or DI output to an amp or PA, and adjust the sound with the three tone controls. I was immediately pleased with the results of this simple test. Plugging in a Martin OM with a K&K soundboard transducer, I found the sound to be clean and clear through my small PA system. The tone controls were effective. The Zoom manual doesn’t specify the frequencies of the tone controls, but I measured them to be, roughly, bass, centered around 80 Hz; mid, centered around 600 Hz; and treble, a shelf starting at about 2 kHz.

The next logical feature to try is the modeling, and again, I found plenty of good sounds to use. It’s difficult to say whether the modeled sounds really reproduce their targeted instruments, but each model does seem to have the appropriate characteristics.  For example, switching to a D-28 model added a more beefy low end to my OM, while selecting an 0 model produced less bass and more mids. Some modeling options were less useful than others—the upright bass model certainly didn’t work well with my OM, but transforming an OM into an upright bass seemed too much to ask, and most models produced interesting and useful sounds. In a live gig I tried the A3 with both the guitar selector and model set to OM-28 and the mix control at 50 percent, and it produced a very nice sound with a little more resonance than the dry pickup.

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The A3’s strengths and weaknesses are both a product of its massive set of features. The unit seemingly provides everything you would ever need, but only if you can figure out which of the 14 knobs to push to operate it. The most basic operations— muting/tuning, activating or bypassing effects, and signal boost—are easily available via footswitch. The anti-feedback feature is also very effective, and readily available. Just step on the footswitch and the A3 will automatically seek out and eliminate up to three problem frequencies. Unfortunately some of the A3’s features require bending over and twiddling the tiny knobs. Even changing between saved presets involves turning knobs that may be hard to reach and see onstage. However, I suspect with a bit of time exploring the unit, most guitarists will settle on a small set of features they actually use, making the need for live adjustments fairly rare.

Self-Contained Powerhouse

Zoom has set a high bar for features in the A3—it’s hard to think of anything significant they’ve left out, and the A3 could easily replace an entire row of stompboxes. Many guitarists will find it attractive just for its clean sound, musically useful EQ, and modeling options. The effects are limited to two at a time, but the large range of options allows you to explore at your leisure and find subtle or dramatic colors to add to your sonic palette.


SPECS: Compact floor preamp with effects and modeling.1/4-inch guitar and XLR mic inputs. XLR DI and stereo unbalanced outputs. Bass, midrange, and treble tone controls. Pickup and mic levels. Master volume control. Footswitches for mute/tuner, boost, and auto-feedback control. Large collection of effects, including reverb, chorus, phaser, compression, EQ. Full suite of modeling effects. Runs on internal nine-volt battery, external power, or USB. Made in China.

PRICE: $335 list/$199 street.

MAKER:. Zoom Corp: zoom.co.jp (US distributor: Samson Tech, samsontech.com/zoom, [631] 784-2200)