I've now read this...
http://nwavguy.blogspot.co.uk/2011/0...explained.html
and kind of understand a bit more. especially resistance and impedance being very different.
Is there a way to measure the output impedance of the headphone socket with a multimeter? it isn't specified in the user manual but as it's a direct tap off the speaker output circuit I'm guessing it's 8 - 16ohm?
the two resistors are just reducing the voltage to the headphone socket. right?
And I'm now thinking I should be looking for HIGH impedance / low sensitivity headphones.
It's all very confusing.