I have been scouring my records to find ones with images of Marshall Amps. Here's one. I cropped this photo of the inner fold of Paul McCartney's Wings Over America. Linda McCartney was cropped out of the photo - she us off to the right. That was not intentional, but I wanted to feature the Marshall Amps. It looks like this was done in water color, and the colours really look great here, and on the inner album cover foldout. You can faintly make out some Marshall amps in the background. I was looking up some other stuff about the famous names in music equipment (Fender, Gibson, Gretsch, etc.) and was a bit startled to learn that Jim Marshall of the Marshall Amplifier company is still alive. Not only that, but his company is 50 years old this year, in 2012.
"The classic Marshall Stack, just like I saw on stage behind Peter Frampton a few weeks ago, is one of the defining images of loud rock music. A full stack consists of one head containing the actual amplifier, on top of two stacked 4x12s, which are loudspeaker cabinets each containing four 12 inch loudspeakers arranged in a square layout. The top cabinet has the top two loudspeakers angled slightly upwards, giving the Marshall stack a distinctive appearance. When a single cabinet is used, the complete unit is called a half stack."