[Themilkman46290]

Does it help?

That is the 4497, uses 2 op275 in lpf, those are soldered in, you can roll the gain amp it will effect the 3.5mm if you want to change the opamps used in the 2.5mm then you will need to solder

 

[Merlin-PT]

-> Howto open the BOX (when you have a new opamp to put inside):
Power off, remove the 4 screws each side, remove one silicone or plastic spacer inside (I think its located at bottom).
If you need, take photos, you'll have to put it back, exactly like it was.

Now you need to place the screen and gold buttons facing down, because the golden buttons are loose, they are not fixed to any place and will fall.
Have the box in the air and slowly slide all the insides out to the screen side, never to the buttons side.

See why:
If you slide the board inside the box, with the buttons side up and slide the LCD screen out into the buttons direction, the buttons will fall inside the box into the LCD and scratch it.
So never slide the LCD screen out of the box in the direction of the golden buttons, the boards must go out slowly in the other direction.
Also have the buttons side facing down, so they don't fall into the board and scratch it.
This problem was reported by some users and is a great warning for all of us.

->Separete the boards:
Then you have 3 items outside the box, 2 boards and the battery, you need to careful pull the 2 boards away from each other to separate them.

->Identify the dip8 socket location:
Here you can see the 2 boards separated, in the red circle center it's a dip8 socket, in the socket there is a dip8 opamp.

The opamp needs to be inserted in the same orientation you see in the photo.
There are marks in the opamp, round groove or round dot or a grove in one side, that identifies pin1.
There is also one mark in the socket, we can't see it in the photo.
If you insert it in the wrong position and power on, the opamp will be burned and you'll need a new one.

Maybe others can suggest opamps, I did many modifications and my zishan is far from stock.

Notes:
Opamp in the socket can't be higher than the dip8 opamp seen in photo, higher won't fit inside the 2 boards.

Battery can never be perforated or physical damaged, doing this will probably make a very dangerous fire. Care must be taken to avoid some pins in the board back, keep those away from the battery when you put everything back inside the case. Also don't forget to put the spacer.

When you open the box, you lose the warranty.

 

[oneula]

This is the OpAmp inventory I've acquired so far:

Sparkos SS3602 (dual) this one's big and expensive
Burson V5i (dual) very popular this one usually fits and is expensive
Muse02 real japanese ones are very expensive
LM6172IN
LME49720NA (very popular)
LME49860NA
LT1057ACN
OPA1662
OPA2132U
OPA2604AP
OPA827AD
OPA627/OPA637 (popular)
AD8066 (popular)
AD825AR (popular)

These things can be used in many other devices like amps (I upgraded my LittleBear B4/B4x and Xduoo VD-05 with the first two)
I put in and ran the LME49720NA in my Z3 and liked it the change but recently upgraded that to a Burson V5i. I might try a Muse02 next

The DSD is a little more complicated for me along with the new T1
The Z1-Z3 and Walnut V1-F2 are more my speed.

 

[426563]

Thank you Does it worth it? Its seems not that easy. What is the Benefit?

 

[oneula]

there's an op amp thread here that has allot more info and detailed reviews on the effects on a variety of devices
Changing op amps are not supposed to change the frequency response but some of these op amps have a reputation of being more "musical", "audiophile" than others what ever that means.
In particular the Muse, and Burson.
I haven't seen any measurement evidence, but sometimes more power and cleaner power opens things up more on a device.
The biggest benefit is when you change the other components like capacitors but that requires some decent soldering skills
Some of these modded devices look like frankenstein's monster and not something you could carry around.

But if you could unscrew apart your device, pull out and pop in a new op amp and get a different type if not better sounding device, then why not.

The Yuelin DAP especially made for this type of mix and match experimenting but it runs about $700 USD.
The lower end Zishan and Walnuts are like $25-$35 and great for experimenting.

Reminds me of the ol' Timex and Cambridge Z88 computers I supported back in the 80's

 

[Merlin-PT]

Thank you Does it worth it? Its seems not that easy. What is the Benefit?

I think so, but I enjoy opening everything.
It's fun tinkering and to try to get a better sound, but I don't know the effect of only changing the socket opamp here, I changed a lot more.
Changing opamp, you can try to tune the sound to your liking when you buy and try several different opamps.
You get to learn something new, that you can use in other kit if need.
Only you can evaluate if you want to do it.

 

[426563]

Yes but its not just plug and play you must carefully place the boards and do the right step to dont damage it. And i dont find a Muse02 on Aliexpress. So i think i will stick with it

 

[Merlin-PT]

See some youtube videos to evaluate the difficulty in opening the box.

If you want to change opamps in a cheaper and easy to open dap, I also like "Zishan Z2 ak4490" or "Z3 ak4493".

 

[426563]

I think its not just open the Player. Which component from Aliexpress would you prefer for the Zishan DSD and is there a possible to buy to change the case?

And is there a difference between my Zishan DSD and the Zishan DSD Pro

 

[Merlin-PT]

I think you have the "Zishan DSD PRO", they call the ak4497 version PRO version.
AFAIK you can't buy zishan box, you can buy the same size box, but they don't have any openings, you would have to cut those. If you mean to buy a protective case, I don't know.
I like to buy my opamps from official distributors, this way I'm sure they are genuine.

 

[oneula]

Personally i would source op amps from US or japan companies like Mouser
There's local US distributors of opamps on eBay but not many.

The DSD Pro is a great device all by itself with the AK4497 chip.
It's pretty powerful and in my opinion works best with earbuds like the other Zishan's and Walnuts and not sensitive IEMs
plus there's allot of good quality earbuds out there anywhere from the TOTL DQSM Turandot, Rose Masya and K's K600 to the new FAAEAL Datura and HE150 Pros
Personally I wouldn't mess with it as $100+ investment, if I thought I would break it.

Where as the Zishan Z1-Z3, Walnut V1-F2 and others were made to be messed around with
Even the ACMEE MF-01 looks like its easy to popout the op amp and pop in a new one. Just got to reglue the back cover on.

If you are really interested in the Zishan and modding it, there is a closed facebook group called WaZe (Walnut and Zishan Enthusiasts) It's mostly filopino, indonesian and singapore folks but they are really into modding their stuff. Including new see through acrylic cases.

Here's an interesting take on the DSD Pro versus your typical DAP/Chord combo



WaZe DSD Video

 

[Themilkman46290]

We should stop call the ak4497 version the pro version, it has the worst schematic of the 3 dsd versions, when I first got my ak4490 dsd, I saw that everyone call the 4497 "pro" so I bought it expecting it to be better, but I was instantly disappointed, it has the highest output impedance, making it a lot less compatible, the "pro" makes it misleading, I understand most of you guys never heard the other versions but if you did, I dought you would keep calling the 4497 the "pro" version, maybe the upgraded version could be the "Pro" since it has ad8620 x ad797, or maybe you guys call it the pro version because a lot of professional headphone use higher impedance? Or maybe since it's the only 2.5mm balanced version we could call it the dsd balanced, but "pro" seems misleading since it's the only version that doesn't work well with sensitive iems...... The other versions work much better with sensitive iems... Just saying

 

[Merlin-PT]

I think aliexpress used the word professional on the ak4497 name, but not on the others, so the pro comes from there.
I agree that the PRO label says nothing about the model, so I use the DAC to identify the models and "ak4497 upgraded" for the upgraded version.

AK4497 has 22ohm output resistors.
AK4497 UPGRADED version has 10ohm output resistors.
These 2 versions have output capacitors in the unbalanced 3.5 output and no capacitors in the balanced 2.5 output.

According to this post from Ivan, we can lower the 2.5 balanced output impedance in ak4497 versions:
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-168#post-15263859

Do you know what are the output resistors (if any) in the 4490 and 4495 versions?
Where are the output capacitors located on these versions, also in the 3.5 output?

Listening to my moded version, ak4497 has more detail than the previous AK DACs I've heard.

 

[oneula]

I have the 4490 Z3 and the 4497 DSD
and I'm getting the 4493 version of the Z3 to compare to the 4490 using upgraded op amps
I initially rolled the Z3 4490 with a LME49720NA which "seemed" to improve the sound quality but again that just could be the modders placebo effect
I now have the burson V5i in the Z3 to compare
I may try the OPA1622, OPA627 and Muse2 next
It would be nice to have 3 or 4 of the Z3's on different op amps to run switchable blind tests to find the best match
kind of a pain to have to keep taking apart the device to do this with one device
It's also a silly venture using a Burson and Muse in there since they by themselves both cost twice as much as the DAP.
Hey but if you can get a $20-$30 4490 or 4493 Z3 DAP to sound as good if not better than an virgin $100 DSD with a line out and a physical on and off switch then it might be worth it because of the pocketable size of the Z3 form factor. So far I haven't got any of my Zishan's modded or not to sound as nice as my Nuansa P1 from Revamp Acoustics playing wavs but then the Nuansa was more that twice the cost of the DSD. TJ tuned that Walnut style device really well plus it already comes with a Muse like the MF01

Someone mentioned here that you get will the best output running DSD files through the DSD 4497 because that was what it prefers and my general testing seems to support that
I know mine seems to hates HI RES AIFF stuff. The HIRES Nora Jones album I downloaded from HDtracks in AIFF format just screaches horribly on the DSD as do other AIFF encoded tracks. It must not be able to read that format.

 

[endia]

I think aliexpress used the word professional on the ak4497 name, but not on the others, so the pro comes from there.
I agree that the PRO label says nothing about the model, so I use the DAC to identify the models and "ak4497 upgraded" for the upgraded version.

AK4497 has 22ohm output resistors.
AK4497 UPGRADED version has 10ohm output resistors.
These 2 versions have output capacitors in the unbalanced 3.5 output and no capacitors in the balanced 2.5 output.

According to this post from Ivan, we can lower the 2.5 balanced output impedance in ak4497 versions:
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-168#post-15263859

Do you know what are the output resistors (if any) in the 4490 and 4495 versions?
Where are the output capacitors located on these versions, also in the 3.5 output?

Listening to my moded version, ak4497 has more detail than the previous AK DACs I've heard.

3.5 single ended is the only output on dsd4495 and no resistors there. caps are just between the buf634 and output socket.. afaik.
also, it's output impedance is less than 1 according to @hakuzen's measurements;
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-30#post-13183626.