I have a EA iAMP Micro 300. My guess is that it's 8-10 years old, having bought it used. It puts out a nice upright sound but has a couple of problems. I notice that it occasionally creates quite a bit of static. This may to be related to the power source or perhaps to the detachable power chord. Another problem is that the volume seems variable. At times it has a bit of volume at other times I just can't get enough. Neither of these problems are consistent. They seem to come and go. Any thoughts about the causes or solutions?