[suicidal_orange]

EDIT:  I turned the light on - not only is there a notch (far smaller than the pic suggests) but the pins have tiny numbers next to them too.  No wonder no-one else had a problem

 
 
 
I guess it's just me but when I look at the pinout on the iBasso websiete (see below)
it looks obvious which is pin one relative to the notch.  Now I have the connectors in my hand (male and female) and the only two notches I see are above one pin instead of between two

 
Thanks in advance for any help finding pin one!