Acoustic and semi-acoustic guitars produce a sound that covers a wide frequency range, and therefore need a special system of amplification. The AC-100's unique tri-amp system and two-way/three-speaker configuration accurately reproduce the deep lows and harmonically rich highs of acoustic guitars.

Two 5-inch speakers take care of the mid-to-high ranges, and a 12-inch speaker is dedicated to the mid and low ranges. The 12-inch speaker is powered by a 50-watt amp, while the two 5-inch speakers each have their own 25-watt amp. This setup gives you a full 100 watts of power, with a much wider frequency response than electric guitar amps.

The AC-100 comes with a built-in chorus that features a high-definition DSP chip and a split-frequency space synthesis technique. An advanced version of the chorus used in Roland's famous Jazz Chorus™ amps, the AC-100's stereo chorus takes the naturally full sound of the acoustic guitar and expands it even further. The stereo reverb is also designed especially for acoustic guitars, resulting in a silky-smooth, high-definition effect. Both effects can be turned on or off independently via footswitch.

Because of their highly resonant nature, acoustic and semi-acoustic guitars can produce uncontrollable feedback. The AC-100 features a built-in anti-feedback function that effectively eliminates the feedback problem once and for all. Simply turn the knob to the offending frequency and forget about it!

The sound of an acoustic guitar is also extremely sensitive to different acoustical environments. That's why the AC-100 comes equipped with several functions that let you fine-tune your sound for any room. A high-quality EQ comes with low, mid and high bands, while a shape circuit enhances the edges of the sound. A high-pass filter circuit lets you clean up the "muddiness" from low-range sounds.

The AC-100 is configured with two independent input channels that give you highly flexible performance options. For example, you can combine a "mic'd" acoustic sound with a pickup tone for a classic mixed texture. You can also use the other channel for a vocal microphone or a rhythm machine. Each channel has effects that can be turned on or off independently.

The AC-100 includes stereo phone jacks as well as pro-level XLR outputs that can be switched between post-effects and pre-EQ. Effect send and return jacks are provided for the guitar channel for connection of external effects devices.