Sorry if this is FAQ; a search only readily turned up arguments over "what
is the difference between 'line out' and 'headphone out'?" I know the
basic difference -- power driving ability and output impedance --- but what
I'd like to know is whether one can, if no alternative exists, *optimize*
the use of a headphone out to drive a larger (consumer) amplifier? By
optimize, I mean minimize overall noise and distortion at reasonable
overall level?

I ask, because I've got a reasonably good flash memory-based MP3/WAV with
no line out, and I'd like to use it occasionally to drive a stereo amp in
place of a CD player.

My naive hypothesis is that if I put a voltager divider with the right pair
of resistors R1 + R2 = ??? ohms (8?, 16? more?) on the output, I can
present an optimal load to the headphone out, while presenting a signal of
the right peak voltage to the input of the amplifier. This assumes of
course that the headphone output voltage at a non-distorting volume is
greater than the typical signal amplitude present on a line out. Not sure
whether this is true.

Also, I'm wondering whether the EQ on signal from headphone out is
different than a line level signal in order to account for differing power
driving requirements of bass vs. treble frequencies. If so, would adding a
cap of the right size to the voltage divider compensate for the difference?

It's probably apparent that I'm not well-versed in audio electronics, so
any informed advice is welcome.

Thanks,
Grant