James Adams
Phoenix
During my first year of University I constructed a valve guitar amplifier based upon an AX84 design (High Octane). This became known as Phoenix and features several modifications that distinguish it from the original design.
The amplifier is built into an industry standard 19” steel rackmount case with the valves and transformers mounted on the top plate. The guitar input jack, power switches, controls are on the front plate and the speaker jack, impedance selector and power connector are on the rear.
The cabinet that the rackmount case is fixed into is made from 1.5cm mahogany marine grade five layer plywood with oak corner braces, two of which hold the case in place. The front panel is also plywood, with five large round holes cut into it and flattened hessian stapled in place.
Behind the front panel there are four four-inch four-ohm drivers wired in a series parallel configuration to give a four ohm net impedance, these are connected to the external speaker jack such that when the amplifier is hooked up to an external speaker cabinet, they are disconnected.
