We Test It: Zoom A3 Acoustic Guitar Processor
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| Fig. 1. Input selection for acoustic guitar pickups.|| Fig. 2. The rear-panel connections.|
The A3’s premise definitely caught my attention: It includes an interface/mixer to capture an acoustic guitar’s sound, and an effects processing section with three stages. The first stage takes the relatively consistent piezo (or magnetic) output from acoustic guitars, then “re-models” other acoustic guitar sounds; the second and third stages can choose from among 40 different effects, including three mic emulations.Ins and Outs
One input can be optimized for piezo or magnetic pickups, or a flat response (Figure 1). An additional combo XLR/phone jack (Figure 2) accepts a mic, with +24V or +48V phantom power for condensers; you can switch the mic phase, alter where it’s mixed into the signal chain, and choose three different low-cut filter frequencies (or turn off low cut). Each input has its own level control for blending the piezo and mic ins.
Outs are balanced XLR with ground lift, paralleled with two 1/4" jacks that provide stereo, mono, or stereo headphones out. Construction is metal and solid. Power can come from four AA cells, the included 9V adapter, or a USB adapter (the USB port is for anticipated firmware updates).Models
You choose your source instrument type from 16 different options (various guitars, but also upright bass, bodyless silent guitar, nylon string, parlor, resonator, etc.). I mostly play electrics, but do have a Gibson J-45 and the manual recommends using the “Round Shoulder” sound source for this guitar. For kicks, I called up the Zoom J-45 model and hit bypass—the sound was strikingly similar.
The differences among most of the 28 models are relatively subtle, but thankfully, avoid any kind of “cartoonish” quality and are surprisingly natural. However, note that the Nylon and 12 String models don’t imitate those particular sounds, only representative body types. They were nonetheless useful timbres.Effects
The effects include dynamics, EQ, modulation, delay, and reverb, with variations on each theme (e.g., 12 reverb types). The mic models have two distance and position options, along with a level control. The effects are not only clean and tasty, but have a certain sophistication.Odds and Ends
The anti-feedback detects three different frequencies, and while it won’t do miracles, it can certainly help. There are also bass/mid/high EQ controls, and a boost footswitch with adjustable amount of boost and tone. The user interface is refreshingly transparent; but if you have big fingers, good luck with the knobs—they’re small and hard to grasp. The unit comes with 20 factory presets, which you can overwrite as well as place in a particular order for stepping through with the main footswitch.Overall
The thing that strikes me the most is the defined, organic audio quality. The models sound natural, and the effects seem “reined in” somewhat for acoustic applications. The ability to mix in mic and piezo is brilliant. Don’t expect the models to turn your guitar into something mind-blowingly different, but the kind of EQ changes they add would require a lot of tweaking with a lot of parametric stages (trust me, I’ve been there)—selecting a model is far easier, and the sounds are valid. If Zoom’s intention was to design an acoustic guitar “channel strip’ for stage or studio, they’ve succeeded.SUMMARYSTRENGTHS:
Sweet sound quality. Clever input mix options. Transparent user interface. Matches 16 different guitar input types. Sync to tempo. Solid construction.LIMITATIONS:
Physically difficult to adjust the controls. Don’t expect the nylon or 12-string models to sound like their namesakes.