QUAD 909 balanced input

Hi Thanks for reading I have a quad 909 amp with balanced inputs, but the amp does not use the usual balanced connectors, it uses something called Ampbus

Do you know the pin arragement for this ampbus so i can diy an balanced interconncting cable to my dac
 
Okay Thanks think i have found it. Will need an explanation. Which is the hot (+) Which is the cold (-) Which is the ground / outer screened cable for left and right channel

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