Also, some more details that I think I get correctly from Sony.
The DSP (Digital Signals Processor) inside WM1A/Z and Ta-ZH1ES, even DMP-Z1 are all the same from Sony in-house grown technology. This DSP chip is capable of DSD remastering with Sony in-house customized software. It is capable upto DSD256. However, it is not suitable for S-Master. Therefore, FPGA has to be used inside TA-ZH1ES for this feature, and Walkmans will not have this feature “enabled”. Where as DMP-Z1 will have it enabled by using the “pure By-Pass mode of DSD playback by AKM4497EQ”.
Sony deemed that this is the best of “Native DSD playback in sound performances, also the tonality of AKM chips” are the reason why Sony has decided to go with AKM4497EQ
Sony is back into the game to produce high performances audio equipments and focusing into transportable and portable, and we have already been blessed with the portable WM line of Walkman which will see foreseeable considerable upgrades by Firmwares. For example, the firmware has been under the table cooking for more than a year to perfect the USB DAC features and now is coming to WM lines.
The DSP inside WM is meant for a long lasting future with firmware upgrades and additional features.
However, at this moment, the momentum, the investigations, the engineering are always limited, which resulted in the limits of the current S-Master limitations, which after many trials and errors, was deemed to be outperformed for the purposes intended on the DMP-Z1 by the AKM4497EQ.
This doesn’t meant that Sony is abandoning the signature unique S-Master, but the team is working very hard to keep improving and soon will be releasing for the next foreseeable products lines.
This doesn’t mean that the S-Master inside the existed productions lines are lower performances than AK4497EQ or other Sigma-Delta architecture, just simply S-Master was not suitable for DMP-Z1 intended designs and purposes. For the best of S-Master, there is dedicated Desktop TA-ZH1ES, and then there is portable WM1Z.
Again, let’s repeat. The DSP inside the current productions line are all firmware upgradeable for foreseeable features, and improved performances.
I hope this post was valuable, and help people to see the picture more clearly as of why Sony is doing what it does
Regarding TPA headphones amp chips. Sony had been implementing it with other products and found it to be best performer and suitable for DMP-Z1 purposes. Especially with discrete supportive components. Therefore, the decisions to went with this design. The purpose of the DMP-Z1 is to have good sound performances and not playing by the book
