the delta is a slight step up from the icon, invest in a good power chord to your icon first. However money better spent would be to upgrade the alpha to an EVS Millenium II dac. I did just that and it was a totally jaw dropping experience, much bigger than a transport difference. I have auditioned the alphas and sigmas, but this is clearly much more resolution, warm and soundstage. I'm tempted to get a delta (I've auditioned them extensively) just to make sure I'm not missing any nuance that the EVS can resolve
EVS site www.tweakaudio.com
or search here on EVS reviews
good luck
tom
EVS site www.tweakaudio.com
or search here on EVS reviews
good luck
tom