Yeah @vthokie83 brings up a very important point. I think only the latest Node has a USB out so the Iris won’t work with older Nodes although I read something that one of the model’s maintenance USB port can be reprogrammed to work as a USB out but not sure on that.
That aside, agree that i2S is absolutely the way to go, and along with the recommendations above I’d add the DH Labs HDMI 2.1 that gets very good feedback from users here, and I think they’re offering 10% off on their site. BTW, for i2S you wanna keep the HDMI cable as short as possible and preferably down to a foot or less although not many manufacturers offer that length. Just go as short as possible.
https://silversonic.com/products/digital-cables/hdmi-2-1/
If your budget is tight, I got this 6” HDMI cable from Monoprice for less than five bucks and it was still very capable of conveying the considerable improvements with the Iris and i2S connection so a very cheap/easy way to get your feet wet until you upgrade. There seems to be mixed feedback as to how much difference the HDMI cable makes — some hear a difference but others who spent some $ on an upgrade didn’t get much improvement, so pick yer poison. Anyway, congrats on the new DAC and DDC and hope all works out with the Node. If it does I’m confident you’re gonna be one very happy camper.