Airport Express question extending WiFi without Airport Extreme possible?

[TheGardenTool]

I've tried searching around but have found conflicting information about what I'm proposing to do so I'm wondering if anybody here might have an answer.

My router is an Asus N66U and it works fine, and I'm not looking to replace it.

What I am wanting to know is can an Airport Express be used to extend Wi-Fi if it's connected via Ethernet? I've read it isn't possible over WiFi with a non Airport Extreme, but I've read conflicting things about whether it's possible over Ethernet.

The end-goal:
I'm thinking of buying a non-Airplay capable AV Receiver. I will have a Zone 2 going out to some Patio Speakers but I cannot manage to put in a manual volume control. I would like it if my wife would be able to use her iPhone to control the music out there through AirPlay, which is why I'm considering the Airport Express, along with Volume although I may have found another solution for volume control for non Airplay sources. If it won't extend the Wi-Fi to the room with the Receiver, then I'll just go for an AppleTV with an optical to analog converter.

 

[Archer1212]

Yes it can do what you want. I had it going once with the current gen model, but my router was shit so it didn't work well enough for what I needed. If it doesn't work for what you need you can always return it. Apple Stores have great return policy.