The Zishan dsd's corner

[Merlin-PT]

What you offer is a "pseudo" solution.
In any case, the phase in time will remain inverted
180 degrees. And although the speaker diffuser will
move in the right direction in theory, we will get a phase - incorrect
sound in any case. If it were possible to do this, manufacturers have long
been making "special" headphones...

Thanks for pointing that out, I don't see the big picture here.
My mistake was only thinking in terms of pure sine wave.
180º phase shift is not the same as inverted polarity, I can picture it now.

 

[Setmagic]

I have received my DSDs dual 4497 today!!!
First impresions.

1) What i don't like:
- Plastic-fantastic screen cover scratch as hell and distort view.
- Don't show album cover! (I have covers is folders and also included in files. Old Fiio X3 can show everything.)
- USB DAC 1-2 seconds delay!!! not for games, movies etc.
- Weird graphical menu don't like colors and fonts.
- Sound with 3,5 mm headphone output is... cheap. Distortion like empty box, lack of sub-bass, quality is overall low - big disappointment.

2) What i like:
- PRICE
- Express boot in less than 1 sec and cay load automatically last file in 2 seconds.
- Design! A small black aluminium brick with screws looks like handcrafted.
- Line-OUT Rich and deep sound. Detailed with good saturation and space.
- MODs friendly, i wish i could have equipment and skill to do all of them.

Why they put color screen when covers don't work... black and white OLED would be perfect especially when that ugly colors and fonts in interface.
It's great to have dual DAC especially hi-grade in this cheap and small player. But sound directly from 3,5mm is bad.
I would spend twice as much to have good quality from headphone out. I wish to change my NX3s to have nice portable device but nowe i can't. For this price i am happy and i will modify this as well.

 

[slavalun]

This is film! Take it off!





Redo your files and everything will show!





This topic has been written about many times! Remove the separation capacitors at the output and everything will be fine, but first
make sure that your player has an acceptable DC voltage!
Here's what you have going on right now:



Accordingly, we can't talk about any bass or sub-bass.

It has also been written many times that these devices should be considered as a DIY kit.

I would spend twice as much

At twice the price, nothing really exists. You need to cook at least ten times more, or do
minimal work with this player!

 

[Setmagic]

@slavalun Thank You for express help. I have read a lot but not sure i understand schemes. I am newbie in electronics must make 100% sure where cut-off and prepare.

All my DIY equipment is prepared from my collages from Audiostereo.pl or other forums and bought via market. Now i have a lot of time to learn how to operate in small sized devices.

 

[slavalun]

Yes, these are separation capacitors! But be SURE
to check the level of the constant component!

You should also keep in mind that the amplifier itself in this player
is cheap and of poor quality! So
don't expect any major improvements...

 

[Setmagic]

Yes, these are separation capacitors! But be SURE
to check the level of the constant component!

You should also keep in mind that the amplifier itself in this player
is cheap and of poor quality! So
don't expect any major improvements...

I will keep in mind I think for home use I will plug other amplifier good quality Topping NX3s but outside for now I do little improvment and when I will be ready I go for yours full modification from Player.ru

@edit
I removed this 2 faty caps and here we go! We have mid and subbass. Better separations, soundstage, sweet sound. This is must have mod for Zi. For make shure all will be better I replace OPA to MUSES 8820. I prefer SQ of LT1364 but I leave this in my topping for now.

 

[Area511]

Some more tips: The screen is still just covered by a plastic window, so better cut yourself a screen protector from an old phone protector (not glass ones). It'.s not perfect but better than scratches.
For the cover images I also have some issues, but maybe it also depends on the firmware version so check that you have installed the latest firmware. In general the screen is too tiny anyway to show something really useful.

 

[DBaldock9]

This is film! Take it off!





Redo your files and everything will show!





This topic has been written about many times! Remove the separation capacitors at the output and everything will be fine, but first
make sure that your player has an acceptable DC voltage!
Here's what you have going on right now:



Accordingly, we can't talk about any bass or sub-bass.

It has also been written many times that these devices should be considered as a DIY kit.






At twice the price, nothing really exists. You need to cook at least ten times more, or do
minimal work with this player!

@slavalun Thank You for express help. I have read a lot but not sure i understand schemes. I am newbie in electronics must make 100% sure where cut-off and prepare.


All my DIY equipment is prepared from my collages from Audiostereo.pl or other forums and bought via market. Now i have a lot of time to learn how to operate in small sized devices.

I will keep in mind I think for home use I will plug other amplifier good quality Topping NX3s but outside for now I do little improvment and when I will be ready I go for yours full modification from Player.ru

@edit
I removed this 2 faty caps and here we go! We have mid and subbass. Better separations, soundstage, sweet sound. This is must have mod for Zi. For make shure all will be better I replace OPA to MUSES 8820. I prefer SQ of LT1364 but I leave this in my topping for now.

Just a word of warning - The two series electrolytic capacitors, and the small (20 - 22Ω) series resistors are there for two reasons -
1.) They protect the transistor driver stage & circuit traces (for the 3.5mm headphone output), that follows the socketed op-amp, from damage when the protection relay is energized at Power Up / Power Down. The capacitors keep large amounts of DC from flowing directly to GND, when the relay is activated, which can damage both the transistors and the circuit traces.
2.) Along with the protection relay, they reduce / eliminate the pops & thumps you hear in your headphones during Power On / Power Off.

You may want to deactivate the relay - and plug in your headphones after your DSDs is powered up - if you're going to bypass the series coupling / protection capacitors.

 

[Setmagic]

Just a word of warning - The two series electrolytic capacitors, and the small (20 - 22Ω) series resistors are there for two reasons -
1.) They protect the transistor driver stage & circuit traces (for the 3.5mm headphone output), that follows the socketed op-amp, from damage when the protection relay is energized at Power Up / Power Down. The capacitors keep large amounts of DC from flowing directly to GND, when the relay is activated, which can damage both the transistors and the circuit traces.
2.) Along with the protection relay, they reduce / eliminate the pops & thumps you hear in your headphones during Power On / Power Off.

You may want to deactivate the relay - and plug in your headphones after your DSDs is powered up - if you're going to bypass the series coupling / protection capacitors.

Thanks for advice. This is possible to keep output safe and reach full potential of sound?

 

[slavalun]

The Chinese put protective capacitors there, because the production and price of this player does not involve checking and fine-tuning the device!
Elementary-it's expensive! It is easier to create a Board on a robot machine, using the cheapest components, and for safety to put protective capacitors,
so as not to compensate for losses for burned headphones ...

provided that the circuit is built relatively correctly-these
capacitors are not needed! (but this should be checked before deleting, different
instances may have different values of DC output voltage).
Resistors on the output in this player-can not be removed!
Those who do not understand the operation of separation capacitors-it is better to refrain from these actions!

 

[Setmagic]

How about output power of 3,5mm PO. In PCB I see white 3VDC rail close jack. In spec also is mentioned about that. So 3V means can output 6Vpp (peak to peak) to headphones? Can I just double this output by replacing this? I have demanding headphones Beyerdynamic DT150 250Ohm. Now I am using Topping NX3s who can output 15Vpp 100mW for 300Ohm and ~12Vpp 545mW for 32Ohm load.

 

[slavalun]

How about output power of 3,5mm PO. In PCB I see white 3VDC rail close jack. In spec also is mentioned about that. So 3V means can output 6Vpp (peak to peak) to headphones? Can I just double this output by replacing this? I have demanding headphones Beyerdynamic DT150 250Ohm. Now I am using Topping NX3s who can output 15Vpp 100mW for 300Ohm and ~12Vpp 545mW for 32Ohm load.

The relay labeled 3V has nothing to do with the amplifier's span! This means that this relay is controlled by a voltage of +3V and only!
From memory in DSD 4497 D, the signal span is at least 11.5 Vpp.

There are no problems to get 15 Vpp, you just need to increase the gain, but absolutely
all the significant sound characteristics THD, IMD, noise shelf and others will suffer...
the "Heavy" load is just low-impedance headphones, since they are the ones
require a lot of current and precise current control. And despite the fact that these headphones can loudly "shout" at a frequency of 1 kHz, even from a smartphone,
for linear operation-you will need a very serious amplifier...
I Also want to remind you that all HI-END headphones are low - impedance.

 

[Setmagic]

Thank You again for time to explain.
I am very curious about such big difrences in audio presentation between PO-out and LO+NX3s. I know abou needed redesign PO by DIY. I don't have cables right now for connect y DSDs to my hi-end station Nelson Pass amp, I decided to buy ZiShan's GAD AD III v04 for fun and modifications. I am not a big fan of simple
OTLs tubes amp but for just a reserch purpose. I have read about possibility to change tube in AD III for OPAmps.

 

[moshe tes]

I am new to this forum and I've been looking through it for the past few days. I have a few questions.
1. Looking through the AK4497eq datasheet, I see the suggested lpf circuit. As I do not have much knowledge in electronics, what do you think of replicating the resistor and capacitor values around the OPA1612 LPF considering the datasheet is based on a 15V supply? As I understand it, the DSD uses a 9V system. I'm also using OPA1612 which I think has made the balanced out cleaner and livelier.

2. What replacement inductor do you recommend to replace the 4R7 ones on the analog board? (An arrow link would be appreciated)

3. What minimum value caps can I have on the SE output without the danger of dc element frying my headphones?

4. Has anyone found a satisfactory solution to the VREF 2200uF recommendation?


I am thinking of replacing most of the 10uF and 0.1uF bypass caps with COG/NPO versions. What do you think? The more I learn about this player, the more it seems to me like too many shortcuts were taken in design that make it hard to make it sound better. The buffer end also looks half baked, most high end DAPs I have seen use an op-amp based buffer. How hard is it to do that and maintain a suitable output impedance for high impedance headphones?

Finally, could someone post a list of mods that have been discussed in this thread? If it has already been done, is there a link to find it easier?

 

[Merlin-PT]

@moshe tes
There are too many post with important information and mods to post, you need to search and read parts of the thread.

Spoiler: A few links to my posts, there are many more posts from all

https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-106#post-14742034
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-138#post-14818113
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-87#post-14669824
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-87#post-14669594
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-107#post-14742995
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-102#post-14729684
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-112#post-14761704
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-150#post-14841908
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-116#post-14773107
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-162#post-15097748
https://www.head-fi.org/threads/the-zishan-dsds-corner.826185/page-155#post-14910159

I think I used this inductors, maybe others can recommend more:
https://www.arrow.com/en/products/srp4020ta-4r7m/bourns

Some mods I did in my player:
- Replace the opamps and the electrolytic caps for genuine ones.
- Replace the LDOs and oscilattors.
- Replace all the ceramic caps for X7R from known brands, small values you can try COG/NPO.
(I tried COG/NPO and even other cap types in the opamps circuit, some I like the sound others I hated the sound, in the end I think I used X7R there)
- Replace and increase the tantalum caps in the dac
- Replace the resistors with susumu brand (I use 0.5% 25ppm 0.1Watt 0805, but there are even better models from this brand)
- Follow the DAC datasheet and add the missing caps
- Increase the power reserve caps, add bypass caps near the opamps local power reserve
- Remove or replace the transistor circuit at the output
- Increase the opamp voltage
- etc.

As much as I would like, I don't have free time to reply with more detail.