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DAC-END R (ES9018) full assembled board - version 2

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#1,061
Instability issue is not solved until now.

"...displays starts iterating over different sample rates in a very fast manner, just like in danielkol's video..."

I have the same problem as Corpius. In the meanwhile the problem appears almost every day. Restart helps. But not always.

I found the following:
1. The DAC is extremly sensitive to electromagntic disturbancees. When i turn on my tube amp and the DAC is on before, then often the problem is there.

2. When music changes samplerate... the same

Dear Quanghao,

can you tell us, what we can do to solve this problem?

Greetings

Juergen
 
#1,064
I just noticed that the Amanero is able to power the LED in my USB hub when the DAC is powered and the USB is not connector to my computer
qILE2BYsylJiDhQ844DCxC9Z4xS8qbqDiMA5lQTKsfHVyiNzhpS4MsCUUtUUe3ylsdUIQwgWkDw5gHiERgZcLbT0CSPNDKshPyKZ48WIWQA2qbhIuIGpDYAIoI6RSHOUZ0QBQQh46NCgDJufBU+m1MAzhtakJVVIgKnlYxgiLICQ0Yo50bxghCabdFDIAGeUc0scM3iz1CVbvHLNF0XAIIklSEAUEAA7
. I was really surprised by this, so I made some some measurements. These are my findings:

  • The Amanero is powered over USB, but also by the DAC at the same time!
  • Side 1 of the ISO7640 digital isolator is not isolated from side 2. Side 1 shares ground with side 2. This is also signal ground!
  • Side 1 of the ISO7640 is also powered by the DAC.
I attached an image where I marked the connections. Blue is gnd and red is 3.3v from the DAC and from the Amanero.

Powering the DAC over USB and by the DAC at the same time is generally a bad idea. This is also stated by acko in this post.

Powering side 1 of the digital isolator and the shared gnd between side 1 & 2 totally defeats the purpose of the isolator. This way it can't offer proper isolation. One can even wonder why it's there!
This is also the case with the S/PDIF isolator at the coaxial input. The grounds here connect underneath the PCB by means of a jumper. Last summer I tried removing the jumper, but this resulted in a very unstable behavior. I really don't understand why the digital isolators are implemented this way. I'm sorry to say so Quanghao but, I my opinion this is a bad implementation of the both the S/PDIF and I2S isolator circuits.


Next step is to try removing L1 from the Amanero to make sure that it only get it's power from the DAC. Hope this helps in my pursuit to get this DAC running stable at all times.
 

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#1,067
Corpius said:
I just noticed that the Amanero is able to power the LED in my USB hub when the DAC is powered and the USB is not connector to my computer

I was really surprised by this, so I made some some measurements. These are my findings:

  • The Amanero is powered over USB, but also by the DAC at the same time!
  • Side 1 of the ISO7640 digital isolator is not isolated from side 2. Side 1 shares ground with side 2. This is also signal ground!
  • Side 1 of the ISO7640 is also powered by the DAC.
I attached an image where I marked the connections. Blue is gnd and red is 3.3v from the DAC and from the Amanero.

Powering the DAC over USB and by the DAC at the same time is generally a bad idea. This is also stated by acko in this post.

Powering side 1 of the digital isolator and the shared gnd between side 1 & 2 totally defeats the purpose of the isolator. This way it can't offer proper isolation. One can even wonder why it's there!
This is also the case with the S/PDIF isolator at the coaxial input. The grounds here connect underneath the PCB by means of a jumper. Last summer I tried removing the jumper, but this resulted in a very unstable behavior. I really don't understand why the digital isolators are implemented this way. I'm sorry to say so Quanghao but, I my opinion this is a bad implementation of the both the S/PDIF and I2S isolator circuits.


Next step is to try removing L1 from the Amanero to make sure that it only get it's power from the DAC. Hope this helps in my pursuit to get this DAC running stable at all times.
Click to expand...

I have the original DAC version, without the isolators. With this version, there was a jumper that lets you supply, or not supply 3.3V from the DAC to the Amanero. If you use 3.3 DAC power, than you need to remove the little three pin regulator to the left of the inductor you pointed at. Removing the inductor will probably work too.

Randy
 
#1,068
randytsuch said:
I have the original DAC version, without the isolators. With this version, there was a jumper that lets you supply, or not supply 3.3V from the DAC to the Amanero. If you use 3.3 DAC power, than you need to remove the little three pin regulator to the left of the inductor you pointed at. Removing the inductor will probably work too.

Randy
Click to expand...
Hi Randy

Removing the inductor L1 also cuts the power from the USB, but the isolator is still not isolating USB ground from DAC ground. The design won't let me, because DAC ground connects to both sides of the isolator and to the Amanero's ground. Amanero ground is also USB ground.
 
#1,069
Corpius said:
Hi Randy

Removing the inductor L1 also cuts the power from the USB, but the isolator is still not isolating USB ground from DAC ground. The design won't let me, because DAC ground connects to both sides of the isolator and to the Amanero's ground. Amanero ground is also USB ground.
Click to expand...

Can't help you with that one, especially since I don't have one.

I've spent a fair amount of time and effort modding my PC side, and I think a major benefit has been in quieting down the ground noise. I was going to add in a isolator into my DAC before, but I don't really feel the need anymore. But it may have been easier and more cost effective to add the isolator, I have bought a 12VDC linear PS, and built a 5V and a 3.3V to power my PC.

Randy
 
#1,071
randytsuch said:
I've spent a fair amount of time and effort modding my PC side, and I think a major benefit has been in quieting down the ground noise. I was going to add in a isolator into my DAC before, but I don't really feel the need anymore. But it may have been easier and more cost effective to add the isolator, I have bought a 12VDC linear PS, and built a 5V and a 3.3V to power my PC.

Randy
Click to expand...
Don't forget that each PC has a some high-frequency layouts and components. This can very well lead to ground noise when such layouts are not properly designed. Since we have little or no control over the layout of the motherboards we use, it is in my opinion still desired to use some proper isolation.
 
#1,072
Corpius said:
Don't forget that each PC has a some high-frequency layouts and components. This can very well lead to ground noise when such layouts are not properly designed. Since we have little or no control over the layout of the motherboards we use, it is in my opinion still desired to use some proper isolation.
Click to expand...

Yes, there has to be a lot of HF noise in my PC, and some of it is getting over on the ground. It's just at this point, I have many other projects I want to try, and ground isolation from my PC is a low priority. I may change my mind, and could well be wrong, but that's where I stand right now.

Randy
 
#1,075
Corpius said:
Hi Randy

Removing the inductor L1 also cuts the power from the USB, but the isolator is still not isolating USB ground from DAC ground. The design won't let me, because DAC ground connects to both sides of the isolator and to the Amanero's ground. Amanero ground is also USB ground.
Click to expand...

Hi Corpius and all,

did you try to remove the Amanero powersupply over the USB-Cable meanwhile?

Greetings
Juergen
 
#1,076
Hi Juergen,

The USB cable still delivers 5V to the amanero, but it's not presented to the amanero's power supply. Another way of getting the same result is cutting the 5V line in the USB-cable, but... do not cut USB-ground! Without it the DAC won't play music over USB.

The safest measure is to remove L1 from the amanero. This way it doesn't matter which USB-cable is used.

I remember that you also where experiencing some problems with the DAC, just like I did. Removing L1 from the amanero's solved the instability issues for me. At least I think that it did, but can't be sure because I replaced the controller with my own controller + firmware at the same time. The new controller + firmware gives me access to almost all settings available for the ES9018. It also makes use of a OLED, which is a major improvement over the stock LCD display. I made two videos showing the result. The first one shows the DAC being controlled with the remote and the second one with the push buttons at the front panel.

video 1 (remote control)
https://www.youtube.com/watch?v=wS_3wKF5bT0

video 2 (push buttons control)
https://www.youtube.com/watch?v=7whPIGIZtvQ

A note about the firmware from the link: The source code found on github is written for usage with a Apple remote instead of the stock remote. The forked version I used for my own DAC can not be found at github.
 
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#1,078
Hi Quanghao

It has really taken me a long time get around building the case for my DAC, but now its time. Right now I need to cut the holes for the backplate.

It is possible to get a drawing of the cutouts of the backplate? I would really make things easier for me.

Best Regards Christian
 
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