I'm hoping a Mesa expert can help me with this. I'm familiar with the Search function, and couldn't find much. I've seen many pics of the 400+, and I've noticed some differences between them: *Some have a red power light, some have blue. Is this just aesthetic? *Some have 6-band EQ, while others have 7. Does anyone have experience with both? Any noticable differences? *There's also a difference in the standby and power switches, where some are a smooth curve, and others are V-like. I know the amp has been around for a while, and changes like these happen. Can anyone date or tell me anything about an amp based on these features? Mine's a 7-band, with a red light, and curved switches. Thanks guys.