Ignore all that I said in previous posts Grant!
I'd just assumed the socket was one of a pair feeding only a channel each - as is usually the case!
As you say, the single socket is obviously taking both channels (good old Rega).
There are easy ways of confirming what pins you need to connect to if you know what you're doing (and are making your own lead - let me know if you want to).
Otherwise Al's suggestion of a call to Rega might be your best option.
(I worked in the amp dept. at Rega - never saw that one).
EDIT:
Just seen your post above.
Good stuff
