On the surface the Sony HAP-Z1ES appears to be nothing more than an slick looking iPod interface for your home stereo. However it's under the hood where you find all the high performance, it converts all your stored music files to double DSD then sends that info directly to the DAC chip via a silver I2S cable.
So what, you say ... what's the big deal!
Simplicity!!!
Internal Hard Drive to Processor to I2S bus to DAC Chip. The Burr Brown DAC chip does no processing (math) to the DSD signal, it simply apply's a low pass analog filter around 50,000 Hz. Well above any frequency any audio microphone could capture on the original recording.
PCM "playback" (I'm not touching recording technology) is a much more complicated process where clocks, math, & jitter all come into play. Complications I myself prefer not listen too.
For even "better sound" remove the top cover and install a 1TB internal Solid State Hard Drive. Do a factory reset and it formats the SSD and its ready to roll. (My grandmother did the upgrade for me) She also plugged in the new 4TB Seagate Backup Plus slim to the rear USB port. Now I have 5TB of music storage.
Technology aside the Sony HAP-Z1ES is an absolute pleasure to use and listen too.
A+++
This music server was done right, period. It upgrades the sound quality the a decoding engine and really shines. Now, if Sony would offer a software update for MQA it would be a giant killer, instead of a gentle giant killer. Worth every penny.