Source matters but will only sound as good as the weakest links in a system. I have found Roon to be a weak link and hard to get around. Roon will definitely sound worse on your iMac.
Innuos lets you use squeezelite as the player with Experimental Mode and its an unmistakable improvement. Innuos is expected to release their OS upgrade soon and it is supposed to sound better than Roon. I would wait for it.
As far as DAC's go, using a killer DAC with Roon from an iMac is going to leave a lot of the DAC's capabilities un heard. A killer DAC will reveal the ugliness of a poor source. It won't put lipstick on a pig.
Garbage in equals garbage out.
Innuos lets you use squeezelite as the player with Experimental Mode and its an unmistakable improvement. Innuos is expected to release their OS upgrade soon and it is supposed to sound better than Roon. I would wait for it.
As far as DAC's go, using a killer DAC with Roon from an iMac is going to leave a lot of the DAC's capabilities un heard. A killer DAC will reveal the ugliness of a poor source. It won't put lipstick on a pig.
Garbage in equals garbage out.