OEX-6sr 8 pin Mini Din cable

Hi everyone,
I have an ASR-10 and I have two output expanders. An OEX-6 and an OEX-6sr. I did not have a cable to connect them though. I have seen ads on ebay etc that the cable is not a normal cable etc. Information was confusing. I asked someone online who owns an ASR-10 and has an expander connected and he said that the cable was normal. i.e pin 1 to pin 1 etc. So I bought a standard cable. I have had nothing but issues and hum via my speakers. I have just spoken to thesoniq and he has said that I have the wrong cable. I may also have caused issues in my power supply board now.
Is anyone able to give me a definitive answer on the cable that goes to the output expander and if it is not standard, can anyone tell me of a reliable source that I can purchase one from?
Thanks,
Michael.