[DBaldock9]

The power is delivered by an MP1542, capable to output from 5V to 22V, up to 2A. The DSD is configured to output +/- 9v, which should be enough. (if necessary I can still raise the voltage up to +/- 13V, but I would need to change the caps)

My intention is to clean up all the power stage of the 3.5mm output, removing the dip8 socket too to have a clean flat surface. I can stick the 2 tpa6120 to the pcb using slim thermal adhesive pads, so that I can use the whole PCB as a cooler. But since the power voltage is not super high I don't think there can be any overheating issues.
I 've the doubt if is it worth to use a stripboard or do the wiring "in-the-air"

From the Monolithic Power website - "The MP1542 operates from an input voltage as low as 2.5V and can generate 12V at up to 500mA from a 5V supply."

Looks like the MP1542 can generate the (+) rail.
Which circuit are they using for the (-) rail?

 

[Draknodd]

From the Monolithic Power website - "The MP1542 operates from an input voltage as low as 2.5V and can generate 12V at up to 500mA from a 5V supply."

Looks like the MP1542 can generate the (+) rail.
Which circuit are they using for the (-) rail?

You can get a negative rail from the mp1542 using a pair of diodes and caps, in fact if you look next to the MP1542 (bottom left of the PCB) you will find the diodes (marked as K14)

 

[slavalun]

All welcome in this topic!
My name is Vyacheslav, I am from Saint Petersburg (Russia).
This is my first first post on this forum.
For the last two years I've been interested in modifying players
Zihan.
Let me introduce links to my works in which
my explanations, photos, and measurement results.
The information is provided in Russian, but I hope
with the help of an online translator, much will be clear.
In the future, if anyone is interested, I will try to provide
technical information in English.



Report on the proceedings for the year (2019-2020)
http://player.ru/showthread.php?t=180748&page=421&p=3021554&viewfull=1#post3021554

Review DSD 4499
http://player.ru/showthread.php?t=180748&page=421&p=3022605&viewfull=1#post3022605

Continuation DSD 4499
http://player.ru/showthread.php?t=180748&page=421&p=3023743&viewfull=1#post3023743

ZiShan DSD 4499 MOD SL
http://player.ru/showthread.php?t=180748&page=424&p=3028387&viewfull=1#post3028387
http://player.ru/showthread.php?t=180748&page=425&p=3038019&viewfull=1#post3038019

Zishan DSD AK4497 DUAL SL MOD
http://player.ru/showthread.php?t=180748&page=426&p=3044007&viewfull=1#post3044007

 

[Draknodd]

All welcome in this topic!
My name is Vyacheslav, I am from Saint Petersburg (Russia).
This is my first first post on this forum.
For the last two years I've been interested in modifying players
Zihan.
Let me introduce links to my works in which
my explanations, photos, and measurement results.
The information is provided in Russian, but I hope
with the help of an online translator, much will be clear.
In the future, if anyone is interested, I will try to provide
technical information in English.



Report on the proceedings for the year (2019-2020)
http://player.ru/showthread.php?t=180748&page=421&p=3021554&viewfull=1#post3021554

Review DSD 4499
http://player.ru/showthread.php?t=180748&page=421&p=3022605&viewfull=1#post3022605

Continuation DSD 4499
http://player.ru/showthread.php?t=180748&page=421&p=3023743&viewfull=1#post3023743

ZiShan DSD 4499 MOD SL
http://player.ru/showthread.php?t=180748&page=424&p=3028387&viewfull=1#post3028387
http://player.ru/showthread.php?t=180748&page=425&p=3038019&viewfull=1#post3038019

Zishan DSD AK4497 DUAL SL MOD
http://player.ru/showthread.php?t=180748&page=426&p=3044007&viewfull=1#post3044007

I always followed your work on the russian forum using Google Translator, my most sincere compliments.

 

[Green Golden Retriver]

Has anyone ever tried Zishan AK4499 Pro with Campfire Andromeda 2020 yet?

 

[Themilkman46290]

Has anyone ever tried Zishan AK4499 Pro with Campfire Andromeda 2020 yet?

Do. T think there is a point, campfires are all b.a. Drivers
Zishan has high impedance
It won't sound right..

 

[CopperFox]

Anyone know if there's something that could be used as an extension cable between the connectors of the two pcb boards on a DSDs AK4499?

With something like that it would be possible to make a bigger and better case for the player where the two board would not have to be on top of each other.

 

[CopperFox]

All welcome in this topic!
My name is Vyacheslav, I am from Saint Petersburg (Russia).
This is my first first post on this forum.
For the last two years I've been interested in modifying players
Zihan.
Let me introduce links to my works in which
my explanations, photos, and measurement results.
The information is provided in Russian, but I hope
with the help of an online translator, much will be clear.
In the future, if anyone is interested, I will try to provide
technical information in English.



Report on the proceedings for the year (2019-2020)
http://player.ru/showthread.php?t=180748&page=421&p=3021554&viewfull=1#post3021554

Review DSD 4499
http://player.ru/showthread.php?t=180748&page=421&p=3022605&viewfull=1#post3022605

Continuation DSD 4499
http://player.ru/showthread.php?t=180748&page=421&p=3023743&viewfull=1#post3023743

ZiShan DSD 4499 MOD SL
http://player.ru/showthread.php?t=180748&page=424&p=3028387&viewfull=1#post3028387
http://player.ru/showthread.php?t=180748&page=425&p=3038019&viewfull=1#post3038019

Zishan DSD AK4497 DUAL SL MOD
http://player.ru/showthread.php?t=180748&page=426&p=3044007&viewfull=1#post3044007

Hello and welcome. I've done the mod of removing two opamps on my DSDs AK4499 that I learned from your posts at player.ru, big thanks for the measurements!

Can you make a more detailed guide as to which components should be replaced to improve the power supply stage of the DSDs AK4499?

 

[Themilkman46290]

Anyone know if there's something that could be used as an extension cable between the connectors of the two pcb boards on a DSDs AK4499?

With something like that it would be possible to make a bigger and better case for the player where the two board would not have to be on top of each other.

There are a couple ways, I simply removed the pins on one board and replaced them with longer pins, but before that I had used a wired pcb connector socket, I was lucky and had one in my stash.
It is a bit smaller then then the most common size.

The standard size is 2.something millimeters
The zishan uses 1.something millimeters

 

[londere]

Hello everyone, I follow this thread while ago, I want to know if it's possible or anyone knows if the Analog board (where the ak4499 stands) can be connected to the U1 mobo, the U1 has the i2s out pins so I planing to attach somehow these 2 boards, the reason of this is because my dsd's died, only led work for charging and the diodes marked with W1 are getting hot. Back to the mod, as I know the dsd's had 10 pins so I think these are like this: 5 for i2s, 3 for i2c to control the DAC, and 2 for power. Does anyone know which one are of these? In advance thanks

 

[Brad57]

The AD8620 op-amps in the LPF should be able to drive Headphones.
.
Edited to add -
.
Also, from looking more closely at the photo of the analog board - it looks like the output of the MUSES02 goes to the large series capacitors, then through series resistors, to the 3.5mm headphone jack.
.
Another Edit -
The 2x BUF634 must be driving either the 2.5mm headphone jack, or the 3.5mm line output jack - since they are single-channel devices - so only two channels being buffered.

Are you sure capacitors are added in the output stage to offset dc voltage and not to regulate power supply? Because why would zishan do it , capacitor in signal path =bad.

 

[slavalun]

Hello and welcome. I've done the mod of removing two opamps on my DSDs AK4499 that I learned from your posts at player.ru, big thanks for the measurements!

Can you make a more detailed guide as to which components should be replaced to improve the power supply stage of the DSDs AK4499?

Welcome.
The fact is that the redesign of the power supply circuit is only necessary in conjunction with the redesign of the stage IV and the amplifier.
For now, I can only recommend doing what I've marked in red
in the photo, plus add a resistor between 1 and 4 legs BUF634 from
1000 Ohms, up to 20 Ohms in order to raise the quiescent current in the output stage,
if you need it.
However, you should know that DSD4499 has an inverted polarity
on the headphone output, that is, the phase is inverted 180 degrees and this is
wrong.

 

[slavalun]

I can also recommend installing another one
an operational amplifier, such as OPA2132.
This will significantly reduce THD distortion
the amplifier.

 

[DBaldock9]

Are you sure capacitors are added in the output stage to offset dc voltage and not to regulate power supply? Because why would zishan do it , capacitor in signal path =bad.

I believe that the series capacitors & resistors are there mainly to protect the output circuit from shorts that occur when the output relay is energized, or the earphone plug is inserted / extracted.

 

[Green Golden Retriver]

Do. T think there is a point, campfires are all b.a. Drivers
Zishan has high impedance
It won't sound right..

Oh ok good to know. Would the Zishan Dap works well with stuff like hd6xx or focal elear. Thanks.