Roland ac-90 Owner's Manual

The AC-90 is a high-performance monitor amp developed exclusively for use with acoustic instruments. It is capable of faithfully 
expressing all the harmonic richness of an acoustic instrument’s sound.

• The finely tuned design of the cabinet is meant to 

enhance the sound of acoustic instruments. Within this 
cabinet, there are two 8 inch woofers, two tweeters, and 
a 45 W + 45 W stereo amp—all of which were newly 
designed just for the AC-90. As a result, the unit is 
capable of delivering a more natural, acoustic instrument 
sound across a broad range of frequencies.

• Thanks to a power amp that was designed to be as light 

as possible, and the use of new materials for the woofers, 
an overall reduction in the weight of the unit has been 
achieved.

• Each channel includes a 3-band equalizer.
• GUITAR channel handles both piezo and magnetic 

pickups.

• The MIC/LINE channel offers phantom power, 

produced by highly reliable, dedicated 48 V output 
phantom circuitry.

• Using the MIC/LINE channel for LINE input allows you 

to connect guitars with magnetic pickups. You can also 
use a piezo pickup (GUITAR channel) and a magnetic 
pickup (MIC/LINE channel) at the same time, and mix 
(blend) the sounds together.

• Three kinds of stereo chorus effects are provided. There 

is the spatially synthesized “SPACE” chorus, the “RICH” 
chorus (which is divided into frequency bands), and the 
“WIDE” chorus (which is also divided into frequency 
bands while offering even greater expansiveness).

• Includes stereo reverb developed especially for acoustic 

instruments. This allows you to add a sense of 
spaciousness and natural body to the sound.

• Equipped with delay effects that can produce sound 

with a tonal quality that is soft and tuned specifically for 
acoustic instruments.

• An optional foot switch can also be used to turn the 

effects on and off.

• Anti-feedback features two ways to detect the feedback 

point. You can use the “Manual settings,” or you can use 
the “Auto settings,” which provide for the automatic 
detection of the feedback point.

• You can connect an optional foot switch and use your 

foot to operate this feature.

• The provided Mute switch makes it easy for you to mute 

the sounds for the AC-90’s own speakers as well as the 
sounds from LINE OUT. By using the Mute function, 
you can plug in and out noiselessly at the guitar. 
Furthermore, when you have a tuner connected to 
TUNER OUT, the Mute function lets you tune your 
instrument without outputting any sound.

• You can connect an optional foot switch and use your 

foot to turn this on and off. 

• Includes external input jacks, allowing you to connect a 

CD player, backing machine, or other device in stereo.

• These  include  both  RCA  phono jacks and 1/4” phone 

jacks, making it possible to connect just about any kind 
of device.

• Features DI Out, which allow you to directly output the 

signals input from connected instruments and mics. You 
can also connect a tuner. TRS balanced output is 
supported.

• Line outs feature 1/4” phone mono-output jacks in 

addition to XLR connectors for stereo output. You can 
use a single AC-90 for all applications.

• It also features a Subwoofer Out. Connecting a powered 

subwoofer allows you to play with an even punchier, 
more powerful low end. 

• The amp also provides a headphones jack, which you 

can use when playing during nighttime hours and when 
making sound checks.

• Equipped with a “folding stand,” which allows you to 

change the angle of the amp when using it for 
monitoring purposes. 

• Includes a “speaker stand adapter,” which allows you to 

attach the AC-90 to a speaker stand. This makes using 
the AC-90 easier when you are performing standing up, 
and allows you to use the amp as a simple PA.

• Also included is a carrying case for greater portability.

AC-90_egfispd.book  Page 7  Tuesday, August 14, 2007  10:09 AM