You have to think of the HAP-Z1ES 'as a whole' to extract maximum performance. Just like a race car, every little thing you do to it "will" change its performance ... yes including a SSD. What unique about the Z1 is that it's a total digital solution, no computer, no cables, no nonsense required.
Can the Z1 outperform your MSB DAC?
Absolutely, but not in stock form, remember the Sony was built to a retail price point of only $2000.
However the Sony has strengths that you MSB will never have, I will elaborate later.
Remove a few screws and lift the hood, you will see everything is modular with lots of room to tinker. Notice the 3 separate power transformers, one for the digital processing, one for the DAC Board & Analog output, and a small one for the ethernet networking. Excellent! In the middle you see the digital supply board which uses an inferior DC-DC power converter that unfortunately adds lots of noise. Shame on you Sony! The DAC/analog output supply board uses a better quality linear power supply. Notice I said better quality. Adding a top quality linear power supply "will" enhance performance. What's cool is you can repurpose the OEM linear power supply board to power the digital processor, a totally free bump in performance. While I have yet to personally explore it, no doubt improving the USB/Ethernet power supply will provide some gains.
With the power cleaned up lets take a quick tour of the digital section. Music files are stored on the hard drive delivered via ethernet or ripped on an optical drive. (At the moment the streaming services are too inferior to consider ... adding Tidal would however create a nice wave IMO) What's really impressive about the Z1 is the short digital path from the hard drive to the processor to the DAC chip. The processor does it's work then directly outputs I2S via a silver wired ribbon cable directly to the DAC chip .... NO DIGITAL MONKEY MOTION!!! No Spdif, no USB, no additional power supply aberrations to add jitter or whatever you want to call these distortion niggles.
I'm not one of those guys that will argue the virtues of PCM vs DSD, IMO they both suck, they just happen to be the digital technology we are stuck with at this moment in time. This PCM digital thing is all about timing and to do that we need clocks, one for each frequency. These clocks need power which create aberrations, which alter the timing. The Z1 clocks are low cost, soldered to the output board, and powered via a cheap 3.3V regulator that is board powered via a 5V feed from the analog power supply. Remember that linear analog power supply. This is a nightmarish reality that no audiophile really wants to ponder. The DAC chip also needs power and does a mountain of math on the fly to output an analog signal. Go ahead and stroke the faceplate of your MSB, just understand the same thing is going inside there, albeit with a bit more polish.
Switching to DSD with the Z1 things get a whole lot simpler, we let the main processor do all the math and feed DSD direct via the I2S cable. The DAC chip employ's a simple filter to output analog, look mom ... no clocks ... no math.
Up-sampling all digital files to DSD128, direct I2S transfer, with a simple conversion is the Z1's real Kung Fu.
That brings us to the analog output section, while the Z1 use's op-amps "somebody" really knew what they were doing. There are no caps in the signal path except on the output, all decoupling caps are film. Even more impressive is the tolerance's of the resistors, matched to the hundredth, very impressive. Power supply is +-18 volt from the linear power supply ... the cleaner the power ... the better the sound with this simple circuit. The weak link, you knew there had to be one, is the electrolytic outputs caps. Yea the bean counters got their finger prints all over these cheap filters. The balanced outputs have 'tolerable' blue Muse caps but the RCA outputs use some brown colored turds with bypass buggers. From there things get even worse, an output relay & molex cable to a riser board with circuit traces to plastic RCA jacks. Wow! Get a pair of pliers and a blow torch and rip that junk out immediately if you're stuck using RCA outputs. Shame on you Sony. Shame!
To sum it up, the Z1 is optimized for DSD up-sampling and balanced analog outputs.
While direct coupled output transformers would provide even lower noise and galvanic isolation, the Z1's stock analog output is nothing to sneeze at. To me adding tube outputs are a fool's errand on a device capable of near 120db SNR.
This brings me full circle back to Cryogenic's, this is hard science folks, not some audiophile neurosis nonsense. It relaxes the stress in metals, and yes almost everything inside audio components is made of metal. While the car racers, competition rifle shooters, machine shops ect, all use Cryo as a tool for better performance. Audiophiles divide into camps as if it's some sort of snake oil ... or miracle. Cryo simply destress metals, a process for audio improvement's achieved my no other means.
I really like the Sony HAP-Z1ES mainly because I dislike everything to do with using a home computer to play music. I understand the Z1 was built to a price point, but on the other hand it's easy to get inside and upgrade the weak links. Understanding and modifying audio components to your taste is the ultimate expression of being an audiophile.
Peace.
