Thanks for your information, we try to find on of the PA. How about the GM 388, is it the same power output?? Coz some says that GM 388 more stronger than GM 300.
They made GM300 in 2 different varieties of power levels. One 15W and one 45W. You're probably thinking that the GM388 (25W) is larger than the GM300 rated for the lower wattage.
Since the GM388 is rated for roughly 20% duty cycle, I wouldn't run it much over 7W. You may have a hard time getting the PA to be stable at that wattage, though.