FACTOIDS & TRIVIA
The Ampeg Jet circuit changed at least five times with some of the changes being major and some minor. The result is that each circuit sounds a bit different. The J12-A pictured here has a circuit which has more overdrive and a bluesier tone than the later Jet models, i.e. the J-12-T, J-12-D, and black vinyl J-12, which sound cleaner and brighter.
1964 AMPEG JET J-12-A (l) and 1966 AMPEG JET J-12-D (r)