The 12AX7 triodes were configured into a "cascading" circuit that directed the output of the first triode to the input of the second triode to increase gain. A simple passive tone control allowed treble tresponse to be attenuated.
The power amp stage featured a single ended, cathode biased EL84 tube, reminiscent of the design of the original 1961 Vox AC-4.
Power Transformer
Unlike the original JMI Vox AC-4, the AC4TV was not equipped with a mains voltage selector switch. To accommodate the differences between mains (AC) voltages throughout the world, the AC4TV was equipped with one of four power transformers. The primary winding of these four transformers was wound to accept an input voltage of either 100VAC (Japan), 120VAC (USA), 220 VAC (UK), or 240 VAC (Europe and Australia).
Fuses
The AC4TV was equipped with three fuses. The main fuse, FS4, was mounted inside rear panel mounted AC socket. A T500mAL/250 volt fuse was installed for the Japanese (100VAC) and US (120VAC) markets. A T1AL/250 fuse was installed for the UK (220VAC) and European (240VAC) markets.
Two fuses, FS1 and FS2, were mounted to the main circuit board. FS1 was a T6.2AL fuse that protected the tube heater circuit. FS2 was a T125mAL fuse that protected the high voltage "B+" circuit.
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