ADC for a Phantom?

Hi Everyone,

Recently purchased a Phantom from Devialet to use as a center channel on a 5.1 system. Trouble is I didn't realize I did not have an optical out jack on the receiver I'm currently using to run that system. The receiver only has analog outs and I believe the Phantom only has an optical in jack.
Soooo . . . guess I'm now in the market for a Analog to Digital converter (ADC?). Any recommendations? Anyone else with a similar problem? Given the cost of the Phantom, I probably wouldn't want to go much higher than $500 for the ADC. 
Help and advice are highly appreciated.