[Good Music]

Don't even bother. Many headphones claiming to be 8 ohms aren't anyway !

Just connect it and see if it sounds ok. You won't hurt anything and in
any case
a new pair of headphones will be the cheapest and best option if you're
not
happy with the results anyway.

Graham

Thanks Graham, but I'm actually pretty intent on finding a way to
specifically use this specific old set of 8-ohm headphones, though I don't
want to "short out" my expensive MP3 player's amp. The reason is these were
my grandad's headphones - I just like them and am set on using them,
whatever kind of adapter I have to make :-)