The Carr Rambler has gained an excellent reputation for great sound quality and being extremely reliable. The features should be reminiscent of a Blackface, but with more expanded low end. This is a rare head version of the Rambler, which they produced in far lower numbers. Here's a description from Carr's website -
"Rich, warm, full, round and clear, with a surprising threshold of clean tone, the Rambler’s the ultimate foundation for shimmering chime, twang, jangle and jazz. But these same qualities also make it an outstanding pedal platform, coupling with a wide variety of boost, overdrive, fuzz and distortion pedals like they were one with its own circuit."