Though the Roland AC-90's marketed as a stereo (45W/channel) 'guitar' amp, it looks to be an interesting (perhaps improved) follow up to the Motion-Sound stereo "(50W/channel) 'keyboard' amp: KP-100S, of which I used to own, but later sold because I felt the trade-off for lack of pleasing "smooth" frequency response wasn't worth it's awkward transport weight for it's cabinet size, so . . .

one standout I appreciate about the AC-90 "right off" is the 13 lb weight difference:

Roland AC-90 : 25 lbs - 13 oz

Motion Sound MS KP100S : 38 lbs

Contrary to what I've read & heard from others, "I" continue to hear stereo efx phase cancellation when mixing a stereo sampled instrument voice to MONO (even thru the Bose L1), so prefer maintaining stereo PA output. This said, I'm anxious to audition the Roland AC-90 with my Tyros2, as it looks ideal for smaller gigs, when used in conjunction w/ my 2 Bose satellite speakers mounted on top of the keyboard + Yamaha TRS-MS02 Sub. If the AC-90 incorporates a SMOOTHER frequency response than the MS-KB-100, I'll seriously consider it. Would be interested in hearing feedback from people who've had a chance to audition the AC-90 thru an arranger keyboard + vocals.

Scott

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