Chas, I thought the Traynor K4 worked great with keyboards, like Stage Piano, and organ, like Nord C1 or Hammond XK1...it is more of a stage amp for someone playing in a combo.

I thought it was less than great on an arranger...two powered cabinets are far better for stereo.JMO.
_________________________
Yamaha Tyros4, Yamaha MS-60S Powered Monitors(2), Yamaha CS-01, Yamaha TQ-5, Yamaha PSR-S775.