JMI Vox AC-2, AC-6 and AC-4 Amplifier


1959 "TV" Front AC-2 - 8" Speaker Model



AC-4 - 1962
The white box in the amp is a owner installed 120 to 240 volt step up transformer


AC-4 Control Panel - 1962 model



AC-4 Amp - 1964 model


AC-4 Control Panel - 1964 model

2_Footer
© 1996 - 2024 The Vox Showroom, all rights reserved. No use on online auctions, eBay or Reverb.

The Vox AC-4 was a guitar a small practice amp that was introduced in 1958 and originally marketed as the AC-2.

While the AC-4 was introduced in 1962, "The Vox Story" by Dick Denney and David Petersen reports that the "TV front" AC-2 was first offered in 1958. In his book, Denney recalls that the earliest design for the AC-2 had a 6.5" speaker. Denney indicated that the speaker size was increased from 6.5" to 8" due to poor sales of the AC-2 with the smaller speaker.

In 1960, without any changes to circuitry or power output, Vox renamed the amp the AC-6 to suggest the peak RMS power of the amp.

In 1961, the TV front cabinet styling of the AC-6 was replaced with what what now be known as "traditional Vox styling" and the amp name went back to AC-2.

The AC-2 electronic circuitry is documented on Jennings Musical Instruments schematic OS/009, dated 9/12/61. The amp is included as the AC-6 in a 1960 JMI Vox double sided sales flyer and as the AC-2 on page eight of a 1961 JMI Vox Amplifier catalog.

The AC-2 (and in 1960, the AC-6) would accompany the AC-10, AC-15 and the AC-30 to form a complete Vox amplifier range.

Cosmetically, the 1961 AC-2 had fawn vinyl, brown diamond grill cloth and brass vents, as seen in the photo at upper left. Electronically, the AC-2 had four tubes: one EZ80 rectifier, one EL84 power tube, one ECC81 (aka 12AX7) and one EF86. The amp had two inputs and three rotary controls: volume, tremolo speed, and a tone control that included an on/off switch. A control panel voltage selector plug also housed the mains fuse. A single button tremolo foot switch was included with the amp.

The 3 ohm 8" speaker in the AC-2 and AC-4 was manufactured by Elac in Germany.

In 1962, the AC-2 was renamed the AC-4. The new name might suggest an increase in output power, but this was not the case. In reality, the AC-4 had the same circuits and power output as the AC-2. The original power output of the AC-2 was about 3.5 watts RMS (6 watts peak), so JMI chose to rename the amp to AC-4 to reflect the actual power output. After a small handful of very minor electronic revisions, a new service schematic, JMI OS/051, dated 9/25/64, was drawn for the AC-4.

The amp shown at lower left is shows the AC-4 in "mid 60's" cosmetics. It was covered in black "basket weave" vinyl and had brown Vox grill, a hinged handle, and two metal cooling vents.




Features - 1962 AC-4
Output Power 3.5 watts RMS, 6 watts peak
Tube Compliment ECC83, EF86, EZ80, EL84
Channel One Two inputs,
one volume,
one tone,
one tremolo
Speaker(s) One Elac 8" speaker
Size 16.5" H x 16" W x 7.5" D
Accessories Cover, Foot pedal.







3_Footer




The VOX Showroom!


Photos and editorial content courtesy Gary Hahlbeck, North Coast Music


Any and all material presented herein is protected by Copyright.
© 1998 - 2024 The Vox Showroom and North Coast Music, all rights reserved

The images and editorial content in this web site may not be copied or reproduced
in online auction sites such as eBay, Reverb and Craig's List. Sellers may provide a link
to the Vox Showroom web site if they wish to refer to this copyrighted material.


URL: http://www.voxshowroom.com/uk/amp/ac4.html