Welcome!
My first reaction to your question is: yes.
The YSP-900 is a self-contained unit that has it's own amplifiers. So you need to send the signal to the unit. How do you do that? I'm not too familiar with Apple Ipod products. So here is what I see as options.
1. Buy a Y-adapter that outputs from the Nano's headphone jack and splits to a L-R cable setup that will input into the L-R audio jacks on the back of the YSP-900. I do this with my Creative Zen on my home receiver. It is the cheapest option usually as the adapters are all over the place and can found almost anywhere. Edit: You don't need a $100 name-brand cable for this! If you spend more than $20 you spent way too much and should have no issues finding options for less than $10.
2. Look at the cable packages from Apple or others that adapt the Ipod line to connect to a TV. The audio output is L-R which would be connected to the L-R audio input on the back of the YSP-900 as in option 1 above. You just don't have to connect the Yellow video cable to anything. It's a more expensive option that 1 above, but it is viable.
3. Look at docking stations to see if they have a L-R audio output that would allow you to connect to the L-R audio inputs on the back of the YSP-900.
I can't upload the manual for the unit here do to file size, but you can register with Yamaha and download it from their website. You can then read how to make connections and such.
Good luck!
