See the video review of the Roland AC-90

Finding the right acoustic guitar amplifier can be difficult if you’re an inexperienced amp user. It is all too easy to induce a wailing wall of feedback, and without the right tweaks and tuning, it is also possible to make your otherwise sweet acoustic sound harsh or metallic—robbing the instrument of its natural character. Furthermore, whether you are a delicate fingerpicker, hard strummer, or someone in between, matching the character of your playing to the characteristics of an amplifier can be an exhausting process of trial and error if you don’t know what to look for.

With the AC-90 Acoustic Chorus, Roland has gone a long way toward alleviating the guesswork in an amplifier search. It delivers a wide array of tones that will appeal to a broad spectrum of acoustic players. And it strikes a balance between clarity and warmth that will keep players reveling in the bliss of experiencing their guitar’s true tone, at a price that’s relatively easy on the pocketbook.

FUNCTIONALITY AND FEATURES

The AC-90’s subdued all-black cabinet conceals a formidable and powerful amplifier design. The 90-watt circuit (2 × 45) features two input channels that can be used for guitar and voice or two guitars, and a three-band equalizer for each channel. The guitar channel can be switched between optimization for either piezo or magnetic pickups; the mic/line channel, which features ¼-inch and XLR input jacks and 48-volt phantom power, can be used in parallel with the guitar channel if you want to add vocals or a second guitar. Each channel also has a separate volume control that is used with an additional master volume to blend sources and customize your tone. And abating the ever-present risk of feedback is made easy by the AC-90’s antifeedback control, which enables players to isolate and dial out problematic frequencies.

The cabinet is outfitted with two eight-inch speakers and two tweeters, facing slightly off-axis and outward from each other to more effectively disperse sound in small- to medium-size areas. The back access panel features a ¼-inch output for a subwoofer and allows you to plug in a CD player or drum machine through two RCA inputs or two ¼-inch phone jacks. It also has two XLR line outs as well as a ¼-inch mono output. There is also an input for an optional footswitch from which you can control mute, antifeedback, chorus, and reverb/delay.

FINDING A TONE

I tested the AC-90 with a 000-size Blueridge BR-343 outfitted with a Fishman Ellipse blending system (onboard mic and undersaddle piezo), and a National Style O with a Highlander iP-1X biscuit pickup. Running both instruments through the guitar channel, I was able to dial in a bright yet warm tone with a few minor EQ adjustments. While the AC-90 imparted a little too much bite with the EQ set flat, a minor midrange reduction transformed the Blueridge’s tone into something very transparent and warm. The barkier National required an even more aggressive reduction of the mids and a boost in the bass, but, like the Blueridge, ended up sounding very rich. Moreover, both guitars maintained their acoustic character whether I fingerpicked blues tunes or strummed with a heavy pick attack.

Playing the Blueridge through the mic/line channel yielded a darker sound, perfect for blues. While the guitar channel has a brighter, crisper sound, the mic/line channel seems to roll off some of the higher and lower EQ, which allows a player to dig in without any ear-splitting high end.

Roland is known for its high-quality Jazz Chorus amps, and the rich chorus sounds that made those amps famous are a central feature of the AC-90. The chorus ranges from a Space setting that sends the effect to one speaker while leaving another dry to a more-saturated, wide-setting chorus. The chorus does induce signal clipping under heavy picking, and there is some drop in volume, but it still possesses a beautiful shimmering quality—particularly at more extreme settings. While the traditionally minded guitarist might find these options a bit esoteric, it’s perfect for Andy Summers–style picking, and I couldn’t resist trying out a little “Message in a Bottle” riffage.

The AC-90’s reverb was warm, and discernibly better than a lot of digital reverbs I’ve used, which can sound a little harsh. A lack of control parameters diminished my enthusiasm a little—you can only change the time of the delay and not the mix. And while the omission saves space and clutter on the control panel, it renders the delay much less useful.

When I played to a room of about 50 people, the Roland performed admirably and proved to be a very capable complete gigging solution. I plugged the Blueridge into the guitar channel via an L.R. Baggs Para Acoustic D.I. and ran a Shure SM57 that I was using as a vocal mic into the mic/line channel. I found the mic/line channel a bit edgy in the mid-range, but I was able to dial in an appropriate EQ setting easily with a little boost to the bass and a reduction in the mids. Several audience members commented on the guitar’s warmth, and I was struck by the amp’s dynamics and tone, whether I fingerpicked a Blind Blake tune or strummed a Charley Patton tune.

THE WRAP

The AC-90 is the perfect amp for a guitarist/singer-songwriter or small-combo player looking for a sturdy and easy-to-use amp that is loud enough for small to medium rooms. It possesses a warm tone without being woolly or muddled, maintains remarkable transparency even at higher volumes, and is very responsive to EQ tweaks. The built-in effects could benefit from additional parameter control, but the classic and recognizable tones of Roland’s proven chorus will be welcome to many players. Most important, the AC-90 is capable of capturing your guitar’s character in a multitude of performance situations without a ton of headaches, meaning you can pay attention to your playing instead of twiddling knobs.