People I know will disagree no matter what I say, but dang. The 1Z is a total pocket rocket that just went toe to toe with DMP-Z1. Hardly a difference in the holographic soundstage as it’s THAT good. I think I honestly saved myself 850,000 yen of buyers remorse. The only major difference is for headphones that require a lot more juice to drive, the DMP-Z1 is the way to go. Otherwise for all the cans I got, the 1Z hits all the checkboxes. To try to seek even “more perfection” would be ridiculous at this point. For once I’ll probably use what the hobby doesn’t use often which is logic and realize everything is in the palm of my hand thanks to MrWalkman. Wowsers. Sometime next year, I’ll buy another 1A or 1Z just to have the stock sound signature as the differences between those can for sure be discerned. I want to support Sony, but at a lower price. Cheers!
Is Your 1z unit stock?
If so, some of your money saved from not buying the dmp-z1, could benifit your 1z with a
@Nayparm hardware upgrade.
That should boost the unit further into summit-fi territory.
...Tbh, I have been using whitigir version ever since....
Your missing out on latest advancements for worry about tunning synergy.
Yet Dmp-z1 is not just a tunnig but a real upgrade.
Mr Walman DMP fw on 1Z/1A is very good, notes pop out. Very clear and coherent. Its suitable for original 1A/1Z. Now the bad things; not necessarily bad, just improvements... ( at least to my ears).
This sounds alot like system synergy to me.
To offset any headphones that would require more power (like a planar) I use a tube amp connected from the Sony single ended output, and result is spectacular.
This is the advantage of the actual Dmp-z1 Sony stated they wanted to make it have more output power.
And dont forget to get it modded by
@Nayparm So it reaches God-level SQ
I agree no matter the firmware, the hardware mod will boost it further. How much depends on you.
Not to be a contrarian, but with my gear the difference between a DMP-Z1 and this Kaesei 1A is still quite large. They are not in the same tier.
DMP-Z1 has texturing that is insanely Holographic, 3D Like I have never heard before, at least on my planar drivers.
Your comparison with the 1a, which almost has the soundstage of a 1z. The 1z always had a greater soundstage even when I used the previous firmwares.
Also, the 1Z romi soundstage should also be greater than stock, even if it gives a different Tonality.
Also should be mentioned again is the system synergy.
It is common to perceive greater amount of sonic qualities with a greater output power, if the headphones require or respond well to it.
With my Sony outputting into my tube amp, the sound is immense and spectacular with any headphones (I am using the "Oblivion" true hybrid tube amp).
Bit late to the party, but just installed the DMP firmware on my 1Z and comparing it with my actual DMP-Z1.
Well, it most definitely sounds like the DMP-Z1! It sounds much closer to the actual DMP-Z1 compared to the old DMP firmware that came out ages ago.
The great advantage of this firmware is for sensitive IEM's, with the lower OI on the 1Z compared to the DMP. So for example with the Empire Ears Odin, it sounds significantly better on the DMP-WM1 compared to the actual DMP-Z1. Winning!
@MrWalkman you are a god amongst men. Thank you so much for this
This is proof of system synergy.
Looks like the Sony is better with IEMs now.
How about a MrWalkman background to top it off?

Haha
Why is everyone having issues?
Mine was instant straight from first try
I think it is because of many newer windows units have slower PCU.
I didn't bother to regress to stock, as Mrwalkman repeatedly stated so.
I had Sony ++ firmware, and just simply ran the new Firmware.
I let both the Sony and the laptop do it thing, regardless of the progress bars.
That's the trick. NOT to exit or disconnect. No need to because the unit will restart.
Once you see the Windows opening up from the Sony player, you know it's installed.
Then I close out and start the tunning install.
Then when windows pop up again I know it's done.
I then disconnect and restart the Sony player, as MrWalkman's stated to do, to make sure the Tunning is initiated.
I feel anyone who has issues, is because they're not patient lol.