That is a stereo EQ with a 7.1 receiver. They aren't really compatible. The only line level preamp out is for the subwoofer. This isn't a marriage you can make work, even with a shotgun.
Thanks for reply, I am not good about sound system. You think receiver VSX-1021 is all in one surround system, so I don't need anything else. Please show me compatible sound system with EQ Behringer 1502 hook up (ex: mixer karaoke, DVD Blu-ray player...)! Thanks for your help
That is a stereo EQ so you can only use it with a two channels of a system.
If you want to use it with a receiver that only has speaker level outputs then you would need a speaker to line level converter connected the front L/R speaker terminals. That will give you an input for the EQ. The output of the EQ would have to go to an amp that would drive those speakers.
You can't use it to EQ the entire system. If you wanted to use it with a powered sub you could use one channel of it between the line level sub out of the receiver and the subwoofer input.