[Merlin-PT]

@Draknodd
AFIK the USB interface is inside the stm32f745.
Probably they run code in the cpu to implement USB audio driver when we select the DAC mode in the interface, but I'm just guessing.

Did you already changed the LDOs and OSCs?
If not, try the LDOs first, to see what impact each mod has.

@Ivan TT
I'll try that, it was planned.

I was just looking at the opamps power supply and I measure these:
any opamp pin 4 to gnd = -8.86V
any opamp pin 8 to gnd = 9.26V

Do you know if it's ok to have this difference?

 

[Ivan TT]

was just looking at the opamps power supply and I measure these:
any opamp pin 4 to gnd = -8.86V
any opamp pin 8 to gnd = 9.26V

Do you know if it's ok to have this difference?

It’s not a problem as long as the output is not pushed close to the rails voltage (high impedance headphones playing really loud), but even then most likely will result in onset of clipping kicking in on the negative swing a bit earlier.
I would not worry about it and have similar difference in mine.

 

[Draknodd]

@Draknodd
AFIK the USB interface is inside the stm32f745.
Probably they run code in the cpu to implement USB audio driver when we select the DAC mode in the interface, but I'm just guessing.

If only the firmware was open source

 

[DBaldock9]

For the adventurous who want to create their own "DSD" - there's this ARM Cortex-M4 development board, with a color touchscreen, and an I2S header (CN12 on Image 2, Pins 10, 12, 14 on Image 6), for ~$70.
https://www.arrow.com/en/reference-...32f469ni-mcu/4ea9092e6b52d58468e1673eb5be72cd

It would probably work as a replacement controller board, to use with the AK4497 DAC board from DSD.

 

[Merlin-PT]

With android it does not work at all because the usb receiver does not tell the o.s. during the handshake its bit depth/channels/max freq. that it supports. And while win or macOS just use a standard 16/48 Android needs those infos to send the audio.

In android audio works (with my nexus 5 + OTG USB cable), I tried with youtube and a signal generator I had.

If you need, also try neutron music player that uses direct USB access.
I didn't explored it, but I had neutron previous configured for direct USB access and it works.
https://play.google.com/store/apps/details?id=com.neutroncode.mpeval

EDIT:
On the subject of the 48Khz limitation, here you can find detailed information about the USB audio implementation in STM32:
https://www.st.com/resource/en/application_note/dm00189562.pdf

I only opened the doc and didn't read it, but I could see they use the internal 48Mhz OSC and a 1000 divider and that limits the supported sample rates to 48Khz. I didn't investigated further to know if other dividers are possible or external clocks are supported for USB audio.

 

[OneL0ve]

New Zishan DSD owner here. Firmware 0.4H.

I just inserted a 200Gb micro SD (exFAT) with 11,000 files (.mp3, .flac) and the player keeps crashing.

What's the solution? Is 200gb not supported or is it the format or what? Thanks!

 

[abartels]

All files in one folder?

 

[abartels]

I have 250gb spread over 500 folders, no problems at all unless i stress device with pushing buttons too quickly

 

[OneL0ve]

All files in one folder?

No. Several folders.

 

[Draknodd]

In android audio works (with my nexus 5 + OTG USB cable), I tried with youtube and a signal generator I had.

If you need, also try neutron music player that uses direct USB access.
I didn't explored it, but I had neutron previous configured for direct USB access and it works.
https://play.google.com/store/apps/details?id=com.neutroncode.mpeval

EDIT:
On the subject of the 48Khz limitation, here you can find detailed information about the USB audio implementation in STM32:
https://www.st.com/resource/en/application_note/dm00189562.pdf

I only opened the doc and didn't read it, but I could see they use the internal 48Mhz OSC and a 1000 divider and that limits the supported sample rates to 48Khz. I didn't investigated further to know if other dividers are possible or external clocks are supported for USB audio.

What android versione do you have on your nexus? I tried on my Lg v20 with oreo and on my XZ Premium with pie and it gets detected but it doesn't reproduce anything

 

[Merlin-PT]

Stock android 6.xx marshmallow in nexus 5.
Lineageos android 7.xx in LG tablet.
Stock android 8.xx in xiaomi A1.
First 2 with micro usb cable + OTG cable.
Last one has usb type-c, used the same micro usb cable + USB to type-C adapter.

They all work, tested with youtube.

What cable are you using?

EDIT:
USB type-c cable connected to type-c phone + usb OTG adapter connected to zishan didn't work.

 

[Draknodd]

Stock android 6.xx marshmallow in nexus 5.
Lineageos android 7.xx in LG tablet.
Stock android 8.xx in xiaomi A1.
First 2 with micro usb cable + OTG cable.
Last one has usb type-c, used the same micro usb cable + USB to type-C adapter.

They all work, tested with youtube.

What cable are you using?

EDIT:
USB type-c cable connected to type-c phone + usb OTG adapter connected to zishan didn't work.

Micro usb+type c adpter. The adpter works eithflashw drives. UAPP recognize the zishan but then no sound.
I just bought amazon micro usb to type c cable... Maybe it's the cable but I don't think so

 

[Merlin-PT]

Is one side of your adapter female usb2 and the other side a typec and you can connect usb2 pen drives to the phone with it?

If so it should work with zishan + a male usb2 to male microusb cable.

 

[Draknodd]

I

Is one side of your adapter female usb2 and the other side a typec and you can connect usb2 pen drives to the phone with it?

If so it should work with zishan + a male usb2 to male microusb cable.

It Is like this but it''s like I wrote above. Get detected but no sound. I'll per you know when the Amazon cable will arrive, it would Be useful because I would use it a lot with Tidal

 

[Merlin-PT]

I don't have UAPP, do you think it could be a conflict with that (if you have it in both phones)?
When you connect it, the phone shows a message that UAPP wants to use USB and you say no and try youtube?