If you care there's software that will let you double-blind test yourself to see what bitrate is transparent for you.
LAME above 165 should be transparent (i.e. sound the same as the source) for most people even with good equipment.
"quality separate CD player, amp and speakers and compared that with an MP3 player plugged into the same amp and speakers"
"MP3 player"
I'd assume that it means iPod-style device, which probably doesn't have as high quality output as "quality separate CD player". Yes, its comparing apples to oranges, but its different from placebo