JMI produced this version of the AC-30 until 1967 when their parent company, Royston, filed for bankruptcy.
The original first-generation AC30 used a GZ34 tube rectifier, three ECC83s (12AX7) for the Normal channel and the tremolo/vibrato oscillator/modulator circuits, one ECC81 (12AT7) phase inverter, and EL34 tubes in the power amplifier circuit.
The circuitry on this Rose Morris produced version of the AC-30 was mounted on a single printed circuit board that was easily warped by the heat generated by the amp.
The original preamp gain structure was attenuated by a new circuit design that limited output.
To many, the most celebrated AC-30 was the top boosted 1964 model manufactured by Vox under the original JMI ownership.
Built like a tank, the JMI AC-30 was hand wired on tag strips fastened to a sturdy steel and aluminum chassis.