Fran,

If I recall correctly, alkaline rechargeable batteries have a high ampere-hour rating than non-rechargeable batteries, but they're still not very high. Therefore, you will get a bit longer life from the batteries before they discharge to the point where they fall below the 10-VDC minimum required to operate most chips and ICs.

Now, the common sense factor comes into play. Is it entirely possible, knowing how much energy a AA battery is capable of supplying, that the reason the amp continued to work for 12 hours was because it is NOT 30-watts RMS? Is it possible that Roland's statement refers to PEAK-POWER? Is it entirely possible that Ohm's law, and the other laws of physics, are correct? 109-dB? For some strange reason I can't find that figure in the manual. On page 18 of the manual under Specifications it states:

Nominal Output Level (1 kHz)
LINE OUT: -10 dBu
STEREO LINK OUT: -10 dBu

What page of the manual did you find 109-dB? Did I miss something?

Gary