|Vox amplifiers that had a separate head and speaker cabinet used a very unusual speaker cable. Vox speaker cables had a 3 pin female XLR on each end of the cable. This was a very unusual arrangement, but Vox had some good logic to support this choice of cable connector.
British Vox amps were powered by tubes, and used output transformers with a fairly thin and fragile winding. If one powers up a 1960s era JMI Vox AC-50 or AC-100 head and neglects to first connect the speakers, the transformer or output tubes could be damaged in moments. The choice of a locking speaker connector, such as the XLR style used in Vox amps, helped to assure that the cable would not be accidentally knocked out of the amp when the amp was operating.
The XLR style plugs and jacks have a much higher current carrying ability than the more conventional 1/4" phone jacks.
I will also add that the use of such a special and non- standardized speaker connector doubtlessly encouraged people that used Vox amp heads to purchase a matching Vox speaker cabinet.
The wiring scheme used in the cables can be seen at left. Standard microphone cables will not work as a speaker cable for Vox amps.
North Coast Music offers this unique speaker cable. Also offered is a similar cable with an XLR on one end and a standard 1/4" plug on the other. Click here to go to the North Coast Music web page that offers these Vox cables.