Thanks Vinnie for all replies so far, yet here's me with another silly question.
I may have missed it in one of the earlier posts so far but would have one more querie in the power supply
Will the amp be powered in any case by the internal battery even when the wall wart is plugged in?
In other words is the wall wart just for charging or can/will the amp be powered by the wall wart when plugged in?
I seem to remember that the Isabella had a switch to change between wall wart and battery but maybe I got this wrong...