861 (non se):
older (from 2001)
unreadable display
plastic remote
Typical Wadia sound (big sound and punchy in bass section. A more blur sound.
581se:
New (from oct. 2007)
You can read the display from a distance
A loooong loading time (between 15-20 sek.)
Nice aluminum remote
Big sound, but a lot more output in the middle range and NOT the typical punchy Wadia bass
More dynamic, bigger sound, better control,
It simply produced a better sound in any way!