Separate head and speaker cabinet systems, often referred to as piggybacks, became a solution in the early 1960s, but it also negated the portability of the combo.
The Portaflex addressed both of these issues, as the electronics were mounted on the top panel that could be flipped over.
Given its cool features and history, the Ampeg B-15 is definitely treasure. Fjestad is a freelance writer who specializes in guitars and amplifiers including the history behind them and their current value.
Fjestad has been evaluating and appraising guitars for over 20 years.
Shortly thereafter, Hull and Michael went their separate ways and Hull moved Ampeg to Manhattan where he slowly began building amplifiers and developing the Ampeg name.