What Features Do I Want?
Finding the right acoustic amp isn’t just about evaluating volume levels. There are other sonic controls and applications that make for a smooth playing experience.
One or two channels? Try to envision your future needs, as well as your present ones. For example, you may be performing as a solo instrumentalist at the moment, which makes a one-channel amp ideal. However, if you think you may want to add vocals to the show, you’ll need two channels—one for your instrument and one for a vocal mic. Two channels is also essential if you plan to bring on a collaborator at some point—another guitarist, vocalist, ukulele player, and so on—as your musical partner will certainly appreciate having their own channel from which to adjust level, EQ, effects, and other signal processing. Share the wealth!
Versatile inputs. Don’t get caught short here, as being able to plug in everything you need to perform is key. At the very least, you’ll want a 1/4″ jack for the cable from your instrument and an XLR jack for your microphone. You may want more. For example, a headphone output is critical when you want to practice or tweak tones without disturbing anyone. The acoustic sound of your instrument will still be audible, of course, but any added amplification and processing will be kept between you and your headphones. Furthermore, if you want to enhance your performance with pre-recorded tracks or other audio, you’ll need Bluetooth connectivity and/or a 1/8″ or 1/4″ aux input to play sounds from your mobile device (or other playback system).
Anti-feedback control. Most instruments outfitted with an electronic pickup can generate feedback. At times, the caterwauling shrieks and hums can be considered musical ornamentation. (Jimi Hendrix anyone?) But you probably don’t want feedback gremlins defiling your sensitive, heartfelt ballad about rescuing puppies. An amp’s onboard EQ can sometimes be deployed to seek out and reduce any offending frequencies that are causing your acoustic guitar to resonate and hum, but a dedicated feedback control is even better. A single push of a button or a couple of knob twists can suppress feedback almost instantly. This is one of those controls you’ll probably never need to touch, but when you do need it, it can be a gig saver.
Effects. Many electric guitarists tend to be all about stompboxes and signal processors that can transform the organic sound of their instrument into something dangerous or disturbing or hauntingly beautiful. Acoustic guitarists shouldn’t be excluded from such creative shenanigans, so if you want to dive into effects processing, make sure your amp of choice at least offers onboard reverb and delay. Some acoustic amps up the ante with multi-effects processing that includes chorus, vibrato, tremolo, flanging, compression, etc.
Other goodies. If your music has a fair amount of atmospheric and mood changes, it can help to have footswitch control of features such as effects on/off, as well as channel mute for silently changing out, say, a mandolin for an uke. A direct or D.I. output lets you dial in your stage sound, and simultaneously send your amp’s output to a mixer or P.A. system. This is a great option if you’re playing a large venue or outdoor festival where your amp doesn’t have a prayer of reaching the “back rows.” In these situations, simply let the soundperson connect an XLR cable into your D.I. output, and the venue’s sound system will do all of the heavy lifting for you. Some amps offer a kickstand that lets you tilt the amp and point its sound output towards your head (for more efficient monitoring of what you’re playing) or more precisely aim the signal at an audience that may be sitting higher than your performance spot.