I have the Equinox special edition for HD650.
The long wait was well worth for me!
A OUTSTANDING upgrade from stock cable.
HD650 + stock cable, it's boring , veil, no soundstage, lack of definition and air.
Equinox changed all that for me.
Now I plan to get balanced ... I wonder if Zu (500$ US) will be better to my 250$ Equinox or it's just a slight different color ? Any idea someone ?