The 2015 CES saw some interesting high-end audio products, one of which may be a surprise to those who remember playing cassettes in the 1970s-1980s. Sony has revived its iconic Walkman, but this time in digital form delivering high-quality sound. The $1,200 portable Walkman NW-ZX2 (an update to the $700 NW-ZX1) supports high-resolution audio files. “High-resolution audio isn’t new,” The Wall Street Journal reports. “However, earlier formats including DVD-Audio or Super-Audio CD, both of which were delivered on physical discs, failed to gain popularity. High-resolution audio in the form of digital files has a better chance of market success, analysts say, since they can be uploaded and downloaded over the Internet.”