Not easily I would imagine. You could however build a very nice DAC from scratch using them if DIY is your thing. Alternatively just sell them on Ebay, looking at the sold listings the DACs go for about ~$70 a piece, I suppose it may depend on the grade of the chips you have. DF1704s are $20 or so. You should end up with some cash in your pocket you can use towards a decent modern DAC purchase.