Thank goodness Mesa doesn't have problems like that. Ampeg may have sent the customers new amps before receiving the old one, that is the way good CS is done. The problem is that some people recieved their replacements with the same revision # and the amps didn't even work. THAT!, is not how CS is done. Who wants to buy an amp, then have problems with it and be basically without a amp for a few months as has been the case for many 500 and 7 owners.