A simple solution would be to stream from the iMac to an Airport Express unit and connect it to your 2-channel system.
There are two connection options. The Airport Express has a jack that is a combination analog and digital output. If you plug a 1/8" stereo mini to RCA L/R cable you can go directly to a line-level input on your amp.
For higher quality you can instead use a mini-Toslink to Toslink cable from the Airport Express jack to an external DAC with optical input. I use that setup to stream to an Audioengine D1 DAC in a garage system. There are lots of inexpensive DACs with optical input that should work well for your application.
If you're streaming from the internet radio stations in iTunes that's all you need but if you want to stream from other applications, like a browser, Airfoil software works beautifully.
Any of the Airport Express units after the 802.11g first generation work very well. Used 802.11n units are very reasonably priced on craigslist or ebay. Even the 802.11g units work fine for streaming but may get interference from portable phones or microwave ovens.
There are two connection options. The Airport Express has a jack that is a combination analog and digital output. If you plug a 1/8" stereo mini to RCA L/R cable you can go directly to a line-level input on your amp.
For higher quality you can instead use a mini-Toslink to Toslink cable from the Airport Express jack to an external DAC with optical input. I use that setup to stream to an Audioengine D1 DAC in a garage system. There are lots of inexpensive DACs with optical input that should work well for your application.
If you're streaming from the internet radio stations in iTunes that's all you need but if you want to stream from other applications, like a browser, Airfoil software works beautifully.
Any of the Airport Express units after the 802.11g first generation work very well. Used 802.11n units are very reasonably priced on craigslist or ebay. Even the 802.11g units work fine for streaming but may get interference from portable phones or microwave ovens.