Looking for DAC suggestions

I am looking for a good DAC for my boyfriend. He has a Mcintosh 275 amp and he is now looking to buy a DAC( the one he was looking into was Anedio D2, which is currently out of stock). I want to buy him a DAC under $2000 for his birthday and I dont have any idea about DAC's and which one is good. Can someone suggest a good DAC which will work well with his Mcintosh 275 amp.