I tried a Traynor K4 Keyboard amp out in the local music store.

First, I played the S900, which I was there to demo, and needless to say, the amp just did not have the quality or stereo spread of two dedicated powered speaker cabinets.

However, I tried a Hammond XK1 through it and it sounded very impressive...I wasn't using bass pedals, but the rotary speaker sim was captured perfectly with the K4 and it had lots of power. Then one of guys hooked up a Roland FP4, and again, it sounded real nice, the electric piano with chorus had a nice defined movement, and no distortion, other than what was in the sound when you whacked it.

These type of amp/speakers are made to play your keyboards (organ/piano/synthesizer) through when playing in a combo...they make crappy PA systems, although I guess they may do okay at a small gig, but they just don't handle the myriad of frequencies generated by an arranger....maybe if a sub woofer was added, it may do better.

Ian