When I was in tech school around 1982 we had several of these for troubleshooting. The teachers would put blown transistors or other bad parts in them see if students could repair them. The reason they bought the NADs was because they were cheap and had better circuit boards in them. The cheap...
Well they say the best thing to happen when trying gambling is to lose your first time out. This can be an addictive and expensive hobby. I hope you don't totally give up though. You won't find too many snobs here who will look down on Apple. It can be hard to tell the difference between 320kbs...
Are you using YouTube as a source? The sound quality on there is ok but better equipment might reveal it's deficiencies more. I think DX3 Pro+ should be held on to, can't imagine you finding fault with its sound. Try to test out some other full sized cans, preferably without purchasing them. I...
The first couple tests I thought I could detect a difference. By the fourth test I kept going back and forth and eventually gave up. It could be my old ears and modest equipment, or not.
The NAD will be replacing an Emotiva XSP-1 pre, HK Signature 2.1 amp and Cambridge DACMagic Plus. The LS50 Metas replaced some B&W 683s. A Marantz CD player, Linn Turntable and Velodyne sub will remain.