[Setmagic]

Is it ok to use 15nf (=0.015uF) ? I usually see schematics using 100nF (=0.1uF) ceramic in parallel with 10uF ceramic or more.
(Connected between ICs power lines and GND and near those ICs power supply legs).

Yes, they don't do any harm I add as well 56nF Panasonic best performance film capacitors with ultra low ESL ESR.
So it's now 15nF + 56nF + 10uF (stock one)
I all data sheets for 1622 are only 10uF I know it's a newest generation opamp and TI also recommend 10uF bit I'm just wonder if it helps to add more.
Same with LDO in Zishan we have 10uF, TI recommend 1uF and I was solder 15nF + 47uF but seems it's changes nothing.

Previous Zishan had insufficient amount of capacity but Z4 seems to have right amount. Someone can confirm?

 

[Syncaine]

My review is in Russian. You can use a translator.

 

[Setmagic]

My review is in Russian. You can use a translator.

First professional review I will add link to first post as reference.

Nice pictures and a lot of good words about Z4.
I'm totally agree with You.
I will send You my modded DSDs for play, but it's very expensive shipping via couriers from Poland.

edit
The problem was mostly in connector and cable. Now I have OCC @1,25mm and 4.4mm who is better than OFC @0,35mm 2.5mm.

edit II
I was updated official support list of all supported music files Here
DTS 7.1 is also supported in *.DTS file.
Can read apple AAC but not xHE-AAC.
Standard AAC-LC without problems.
I had troubles with find xHE-AAC becouse most benefits have in very low bitrate.
All modern audiobooks are still in MP3 128-256kb/s so it's still safe to have it.

edit III
I'm rolling capacitors, just add 4x 220uF Nichicon Audio KA for opa1622 and 6x ~180uF MLCC in main DC-DC rail.
I don't see any difference.
Best digital filter in my configuration is Slow Roll-Off, Linear Phase Filter.

 

[Unolord]

My Z4 arrived today.

She's a chunky beast with really clunky software but I knew that going in. The sound quality is fantastic which makes up for the mediocre menu system and the screen. I wish they had put a screen protector on it though. That might had prevented the several scratches on it OOTB.

I did have the fast forward lock up that forced me to use the reset button. Hopefully the next firmware update fixes that and the typos (e.g. FLODER) and merging of words in the volume menu. When I was changing the play through method it merged the words ALL and FLODER into a jumble.

I will use this as my DSD player and keep my other DAPs (Hidizs AP80, Sony NW-A45 and Fiio M7) for regular and HI-Res FLACs.

Again, I do like the Z4. Great sound mixed with some bugs that should easily be fixed.

 

[HashSlingingSlasher]

My Z4 arrived today.

She's a chunky beast with really clunky software but I knew that going in. The sound quality is fantastic which makes up for the mediocre menu system and the screen. I wish they had put a screen protector on it though. That might had prevented the several scratches on it OOTB.

I did have the fast forward lock up that forced me to use the reset button. Hopefully the next firmware update fixes that and the typos (e.g. FLODER) and merging of words in the volume menu. When I was changing the play through method it merged the words ALL and FLODER into a jumble.

I will use this as my DSD player and keep my other DAPs (Hidizs AP80, Sony NW-A45 and Fiio M7) for regular and HI-Res FLACs.

Again, I do like the Z4. Great sound mixed with some bugs that should easily be fi

My Z4 arrived today.

She's a chunky beast with really clunky software but I knew that going in. The sound quality is fantastic which makes up for the mediocre menu system and the screen. I wish they had put a screen protector on it though. That might had prevented the several scratches on it OOTB.

I did have the fast forward lock up that forced me to use the reset button. Hopefully the next firmware update fixes that and the typos (e.g. FLODER) and merging of words in the volume menu. When I was changing the play through method it merged the words ALL and FLODER into a jumble.

I will use this as my DSD player and keep my other DAPs (Hidizs AP80, Sony NW-A45 and Fiio M7) for regular and HI-Res FLACs.

Again, I do like the Z4. Great sound mixed with some bugs that should easily be fixed.

My screen has a plastic screen protector. I think every z4 has plastic in both screen and back. You can peel it off

 

[Setmagic]

@Unolord Buttons have bad design probably in test device they was without foams inside. It's responsible for hardness and fast forward bug.
This is solution

 

[Unolord]

My screen has a plastic screen protector. I think every z4 has plastic in both screen and back. You can peel it off

You know I tried multiple times to see if there was a screen protector via the top right corner and nothing.

Last night I just happened to brush my thumb across the screen and it peeled off! D'uh!

My fingernail game is weak.

 

[Unolord]

@Unolord Buttons have bad design probably in test device they was without foams inside. It's responsible for hardness and fast forward bug.
This is solution

I might do that. I've gotten used to the buttons now.

 

[Belrat]

I got my Z4 yesterday. No problems with the buttons. Just a bit stiff but no rattles like the buttons on the Z3. The language-error in Floder is copied from the DSD. Screen is a shade paler than the screen on de DSD and doesn't look that sharp too. Further it has the same layout. I listen through the 4.4 mm balanced output to my Grado. Sounds very good, but I can't say the difference with de DSD yet. Most hany is having 3 headphone outputs. I had several players (Ziku and Xudoo) that had problems with the headphone output. Always lost one of the channels. I now have two Zishan Z2, one Z3, one DSD and one Z4. In my stereo setup I have a Zishan MD1. From the Z3 up they all have the same UI. The Z3 and Z2 are tweaked with an Muses 02 Opamp.

 

[Setmagic]

I was added Unolord and Belrat impressions to first post.
Today I will make a first MOD of Z4, better capacitors and hyped electrolytic ELNA with silk and "snake oil".

 

[Setmagic]

MOD update 11/09/2021


OPA1622
4x 10uF X7R muRata
4x 10uF Elna SILMIC II RFS
4x 100nF NP0 muRata
Audio capacitors replace instead of X5R:
4x 680pF G0C muRata

I2S rail filtering 4x 100nF C0G instead of tiny X5R 100nF

Resistors in all analog part is replaced for Panasonic Thin-Film 0,1%

OPA1656 (was AD8620, OPA2134, OPA1612 instead OP275)
2x 10uF
2x 1uF
2x 100nF
Audio capacitors:
8x 680pF G0C
4x 2200pF G0C

DAC ES9038
4x 220uF tantal-polimer AVX
8x 10uF X7R muRata
8x 100nF C0G

LDO TI LP5907 3.3 (5x 3 digital + 2 analog (instead Chinese one)
10x 2,2uF X7R
10x 100nF

Replaced 2mm OFC high quality power cables

Filtering main PSU ~9V
(original 1900uF pool of X5R/X5Y?)
+
4x 100nF

filtering digital ~4V
(original capacitors by manufacture)
+
1x 180uF
1x 1uF
1x 100nF

Planning:
- complex EMI shielding and BT connectivity improving

 

[Mr.HiAudio]

new firmware 0.2

in .txt :
Upgrade method
1. Download z4app.bin and put it in the root directory of the USB flash drive. The file system format of the USB flash drive needs to be fat32 or exfat, otherwise it will not be recognized;
2. Turn on the player;
3. Insert the TF card containing z4app.bin into the player;
4. The player will automatically verify whether the current firmware is the same as z4app.bin, and if it is different, it will be upgraded to z4app.bin. When upgrading, the following steps will be performed in sequence. Erasing erase the current FLASH. Writing write current FLASH. If the verification is successful, it will automatically restart or shut down, and the process will take about 1 minute;
5. After the upgrade is successful, check the version number on the setting interface;
6. Delete the z4app.bin file on the U disk, otherwise it will be verified every time you boot.

0.2 version:
Ignore usb removable disk function in UAC MODE or BT MODE mode;
Solve the noise when the 3.5 PO port is turned off;
The balance function is turned on by default;
The default factory volume is 40;
Delete option for delete file browsing

 

[Unolord]

Last night I was using the Z4 before bed. The battery was low so I plugged it in for the first charging since getting it.

OMG was that blue flashing LED light bright! I had to unplug it so I could go to sleep.

On a side note what is the setting to have the Z4 play a single folder (or floder) and stop after the last track? No matter what I select I seem to be stuck on repeat.

 

[Setmagic]

@Mr.HiAudio great news, I was pinned Your message in first post in download section. Can You edit your post for more visible, 1. 2. (...) steps?

• MONO sound in USB DAC mode
• Good to have fixed USB flash option in DAC / BT.
• It's seems to be a little bit louder than V0.1 in same %, maybe higher power limit.
• My default factory volume was 30, but after that remember last volume setting which is good.
• "Floder" still remain, same as "OFFed" EQ
• No more Play / Delete menu option just play that file instantly which is OK.
• Spectrograph is still in wrong position
• Still lagging some DSD256 11Mbit/s files... DSD128 and DSD64 working perfect.
• Don't play multichannel DSD in V0.1 was working.
• Interference of LCD when play 5.1 24/96kHz multichannel. Music is smooth, same as in V0.1 fair enough.
• Auto fast-forward bug when press 2 buttons in same time is still present.
• Sometimes wrong interpretation of 32bit instead 24bit and DSD 6k instead 8k etc - still.
• 3.5mm PO/LO working in Balanced mode as well as 2.5/4.4
• No more pooping sound on/off or changing BT/DAC function
• Stable USB-C file transfer 4,5MB/s
• LCD don't run LED backlight when USB file transfer is ended (still)
• DSD512 and DSD1024 can be recognized, open and play in the same way as 256 with little lagging sound.
• Apple AAC needs more CPU utilization but working without problems 320kb/s
• AAC-LC needs more CPU but working without problem VBR 180kb/s and CBR 512kb/s
• HE-AAC and HE-AAC v2 stereo working with 100% CPU utilization sometimes lagging
• DTS 7.1 is working without any problem

 

[Mr.HiAudio]

@Mr.HiAudio greate news, I was pinned Your message in first post in download section. Can You edit your post for more visible 1. 2. (...) steps?

• Good to have fixed USB flash option in DAC / BT.
• It's seems to be a little bit louder than V0.1 in same %, maybe higher power limit.
• My default factory volume was 30 but after that remember last volume setting which is good.
• "Floder" still remain, same as "OFFed" EQ
• No more Play / Delete menu option just play that file instantly which is OK.
• Spectrograph is still in wrong position
• Still lagging DSD256 11Mbit/s...
• Don't play multi channel DSD in V0.1 was working.
• Interference of LCD when play 5.1 24/96kHz multi channel but music is smooth same as in V0.1 fair enought.
• Auto fast forward bug when press 2 buttons in same time is still present.
• Sometimes wrong interpretation of 32bit instead 24bit and DSD 6k instead 8k etc - still.
• 3.5mm PO/LO working in Balanced mode as well as 2.5/4.4
• No more pooping sound on/off or changing BT/DAC function
• Stable USB-C file transfer 4,5MB/s
• LCD don't run LED backlight when USB file transfer is ended (still)
• DSD512 and DSD1024 can be recognize, open and play in same way as 256 with little lagging sound.
• Apple AAC needs more CPU utilisation but working without problems 320kb/s
• AAC-LC needs more CPU but working without problem VBR 180kb/s and CBR 512kb/s
• HE-AAC and HE-AAC v2 stereo working with 100% CPU utilisation sometimes lagging
• DTS 7.1 is working without any problem

I also noticed that the volume increased slightly. I redid the post above. if there is a new firmware in the cloud then bark me to know, I will download it