The Vox AC-10 from the JMI era is a dual channel amp with tremolo (mislabeled on the control panel as vibrato) and a single 10" speaker. These make for amazing studio recording amplifiers, and are something of a step in between the student / practice AC-4 model and the larger dual speaker AC-10 Twin and AC-15 Twin amps meant for playing clubs. While technically discontinued in 1965 in favor of the better-selling Twin model, these amps remained in the the Vox catalog until midway through 1967.