The Motion Sound review from one of the trade magazines:

PRO’S: Wide, clear sound, compact size. Subwoofer out makes it possible to build a scaleable system.
CON’S: Only two pairs of inputs. No tilt-back feature. No effects loop.
BOTTOM LINE: An excellent choice for small venues.

When we reviewed the KP-100S’s big brother (KP-200, Feb. ‘03), we praised its big, beefy sound and deceptively wide stereo imaging. I’m pleased to say those two attributes are found in the little guy as well. As you’d expect, the 100-watt KP- 100S won’t get quite as loud as its 200-watt sibling, nor will it provide quite as large a stereo field, but it delivers impressively on both counts.

Active EQ can boost or cut each frequency band, and though the panel is labeled with values from 1—10, the number 5 is replaced by the letter N indicating “nominal” or no boost or cut. The EQ points are well chosen and musical. It was easy to clear up muddy Rhodes and Wurly sounds, and equally easy to fatten up thin-sounding imitation analog synth sounds. But not at the same time, as the KP-100S’s EQ is global. Big bottom spoken here: The amp is roughly the size of a Fender Princeton, and sounds completely at home pumping out fat synth basses, concussive kick drums, you name it. Well done. If you need even mo’ bottom, there’s a jack out back that passes all signal below 100Hz to any powered subwoofer (like Motion Sound’s SW-IS at $949).

The stereo expander sounds to me like it’s been slightly enhanced since the KP-200, but perhaps the effect is simply more noticeable because the 100’s cabinet is smaller — the stereo width defies the dimensions of the box even more. As before, this effect is best used sparingly and works its magic only with stereo inputs. At extreme settings, a slight hollowness makes itself known.. Mono sounds stay resolutely mono no matter what you do.

The mic input (dynamic mics only — no phantom power) offers the singing pianist or duo the opportunity to forgo the P.A. on small gigs. There’s enough gain to give a saxophone a little help (Saxes are pretty dang loud anyway) and more than enough to get a vocal out over a digital piano. The mic input has a dedicated volume control, something the 200 lacked. An effects loop would make that solo or duo act sound even better, but no such luck.

The left and right XLR outs make the 100S useful as a two-keyboard mixer/stage monitor, but I want a tilt-back feature too. With the amp on the floor, you’d need ears below your knees to hear any high end. A stand socket would be even better, but.— the story is the same as with the KP-200: The internal baffle board that separates the two speakers is exactly where you’d want the socket.

The KP- 1 OOS continues Motion Sound’s unbroken streak of creating solid, great-sounding keyboard amps that offer something you can’t get on competing models. Try one out for yourself, with my hearty recommendation.

KEN HUGHES