I just acquired a Breeze SU4 AK4490 DAC to pair with my SMSL sAP II amplifier. Now the amp works perfectly fine, but the DAC has serious popping/crackling issues whenever I run it on XMOS USB. The driver installs just fine, and I see my USB XMOS device show up after rebooting my PC. Selecting it plays audio as it should, but I get some very bad crackling/popping sound the moment I switch over to USB mode on my DAC. Optical works perfectly fine (no surprise there) regardless of whether its connected to my Sound Blaster Z or motherboard audio.
Sure I can run it just fine via optical, but XMOS USB supports up to 384k 32bit playback and I want my DAC to run at the best it can.

I'm pretty new to desktop audio so I did some Googling and found out that crackling over USB is a very common problem with many possible reasons for the popping. I doubt its a grounding issue because I am not using a USB hub, instead I have the USB going straight into my motherboard, I even tried different ports including a USB 3.0 port. Isolating the DAC by itself without anything touching it also did not help one bit. Could it also be due to wrong drivers?
Also I see several variants of XMOS drivers with the same version number out there so I'm kinda lost as well. Can someone fill me in here?

Hey!

Sorry to hear about your issue. In my experience it's either grounding, a faulty USB entry point, an issue with the PSU, the power cable or the USB cable or bad grounding (this isn't limited to hubs, this could very well be your whole electrical system, though I doubt it, usually happens with very old buildings that have not changed their installations in years).

Another possibility is the unit faulty, but I don't really want to consider that as the first option. Have you tried to use the same USB connection on 24-bit/192Khz? Since some devices are just partially compatible with anything higher and require WASAPI to work properly.

Additionally, some motherboards go all wacky when connecting typical USB 2.0 devices via USB 3.0 ports due to the amperage diferences (0.5A for 2.0 and 0.9A for 3.0). They sometimes even flag the port as defective due to giving off more power than required for the specific scenario (Had this issue with my EVGA X79 Classified motherboard a few years ago, Thank God I switched back to Z97).

Try running it on 24/192 and let me know if that helps with the popping.

Thanks for the reply!

I tried changing the sampling rate from the lowest to the highest and the result is the same. Although on one occasion selecting the lowest sampling rate (16bit 44100hz CD quality) did help stop the popping for a while, but you can still hear it after a few seconds. At first I thought I had to match the rate as well, but seems like thats not the case here. Anyway 24/192 was the highest sampling rate I could select, not 384/32 which it should support. Driver issues perhaps? I'm on Windows 10 by the way..

Unfortunately I don't have a spare USB cable on hand to test or even another power supply unit. So I'm going to test that I need to buy a new one.

I also doubt its an issue with the DAC itself, unless you're saying the board containing the XMOS USB itself is faulty but not the main circuitry.

Btw I just reinstalled the XMOS driver, the device shows up in Windows as usual but this time I get no sound at all this time! Gonna try an older version see if it checks out.

Try a restart before you do that, it happens sometimes. My Oehlbach suffers from the same disease. Sometimes if I change the playback device it goes comatose. You may want to contact the company and inquire about Win10 support in the meantime.

When I got my Oehlbach XXL DAC Ultra, it only had Win7 support and I was on 8.1. I asked the guys about a driver and firmware update and they came in two days. They also thanked me for letting them know about the issue, so maybe it's worth a shot

Yup I did a restart, still no sound. Its a chinese brand so contacting them will be difficult, but the store I bought it from had links to the drivers, including one for Win 10 which I am using now but I get no sound at all. Even though everything seems to be installed correctly. I just tried this driver package, which seems to be the most complete and up to date of all http://www.xmos.com/support/usb-audio-driver-support

However I still get no sound with it. I can tell Windows is processing audio but for some reason I am not getting any sound output to my headphones no matter what sampling rate I select. I dont even hear the popping noises.

Right now its either:

1. I get sound, but with all the crackling and popping

2. I get no sound output at all, despite the OS processing the audio

Is it a mix of a driver and/or possibly PSU issue? I'm so confused. Right now I feel like I should have just gotten the DAC without the XMOS USB support at a lower price and just use it via optical.

I'm actually at a bit of a loss. I assume it's most likely a driver issue.

Ok, one thing which is a complete longshot and you can try out is simply uninstalling the driver altogether, then when you install it (all drivers in this equation, for that matter) do the following:

1. Right-click on the driver setup exe file
2. Select properties
3. Go to the compatibility tab and check the "Run in compatibility mode with" box
4. Select Windows 8
5. Tick the "Run as Administrator" box
6. Proceed with the installation.

This needs to be done for each driver.

Also you may want to check for new firmware updates. I know you probably have, but just trying to help

How many drivers do I have to install in total? I only got the XMOS USB audio driver, though I'll try installing it using your method. Is there another driver I'm missing out?

I don't know for your case, particularly, but some devices have more than one. I assumed you have one for the XMOS itself another for the Breeze so that they can not only function with each other, but with Windows, as well.

Have you tried testing it with other headphones? I doubt it's the headphones, but I'm running out of ideas at this point...

EDIT: Nevermind, stupid question, you said that it doesn't happen on Optical.

Just tried installing the drivers via your method, and its the same.. And as for 32/384 not showing up, its probably because Windows does not natively support that high of a sampling rate, you need special drivers and the hardware for it. Even so I think it does not show up under Sound > Playback Devices but it does not necessarily mean 32/384 is not being processed when it should. (Just a guess?)

Since I am on Windows 10, I was told to install these drivers from a seller on Aliexpress, it was the same driver linked on the Taobao listing I bought the DAC from. http://yun.baidu.com/share/link?shareid=2911941438&uk=155645262

As you can see its a rather old driver, the latest XMOS USB Audio driver as of the time of this post is 3.2.0 and the one provided is 2.19. Even so I get the exact same problem with the popping sound. Maybe I should try a full system reformat one day when I have the time and install the drivers on a fresh OS and hopefully it works. If not I'll have to somehow acquire another PSU to test.

The only way to get 32/384 if it's not selected in Windows (Thought it should appear, because it does for mine), is to use WASAPI, which bypasses the Windows kernel. There is a Foobar plugin especially for that.

Also, don't you have a friend with a PC where you can test your setup? It sounds easier than getting another PSU.

Guys, I think you may be barking at the wrong tree. Crackling is usually a result of buffer underruns or overloaded USB bus. In some cases it's also the CPU not given enough time to handle the audio tasks, and 384/32 will push your PC a fair bit.
Start with increasing the buffer size in your player if you haven't done it yet. 1500 ms should do the trick, but try going higher if that helps.
 
If you're using Foobar with WASAPI, keep in mind that there is additional hardware buffer that may have to be increased as well: in Preferences go to Advanced -> Playback ->WASAPI and set both buffers to something like 250. While there, tick the high worker process priority. Check also Advanced -> Playback -> Thread priority and set it to 7.
 
If all that doesn't help, google for latency monitor and get it - it's a free utility that will show you which processes may be stealing too much CPU time from the audio.

pleasantsounds said:

Guys, I think you may be barking at the wrong tree. Crackling is usually a result of buffer underruns or overloaded USB bus. In some cases it's also the CPU not given enough time to handle the audio tasks, and 384/32 will push your PC a fair bit.
Start with increasing the buffer size in your player if you haven't done it yet. 1500 ms should do the trick, but try going higher if that helps.

If you're using Foobar with WASAPI, keep in mind that there is additional hardware buffer that may have to be increased as well: in Preferences go to Advanced -> Playback ->WASAPI and set both buffers to something like 250. While there, tick the high worker process priority. Check also Advanced -> Playback -> Thread priority and set it to 7.

If all that doesn't help, google for latency monitor and get it - it's a free utility that will show you which processes may be stealing too much CPU time from the audio.

Click to expand...

Thanks, I'll check it out. A friend of mine also advised me to use a latency monitor to check. Though I get the popping noise even when the device is set to the lowest sampling rate of 16/44100 in Windows. Which is the default sampling rate set just after installing the XMOS drivers.

pleasantsounds said:

  Guys, I think you may be barking at the wrong tree. Crackling is usually a result of buffer underruns or overloaded USB bus. In some cases it's also the CPU not given enough time to handle the audio tasks, and 384/32 will push your PC a fair bit.
Start with increasing the buffer size in your player if you haven't done it yet. 1500 ms should do the trick, but try going higher if that helps.
 
If you're using Foobar with WASAPI, keep in mind that there is additional hardware buffer that may have to be increased as well: in Preferences go to Advanced -> Playback ->WASAPI and set both buffers to something like 250. While there, tick the high worker process priority. Check also Advanced -> Playback -> Thread priority and set it to 7.
 
If all that doesn't help, google for latency monitor and get it - it's a free utility that will show you which processes may be stealing too much CPU time from the audio.

Click to expand...

I don't think that should occur with any CPU that's dual core or better, but you do make a valid point.

This caused me to think about it for a bit and consider other options:
Do you have any sort of power saving options on?
How much RAM do you have? In theory when your system uses up its RAM and it doesn't have enough memory available, it writes to the page file on your system, if you have one. If not, it frees up some memory and writes into the RAM again. I don't know how that practically translates into the effect on sound, but in theory it could be responsible for underrun.

Additionally try setting your players priority to high (NOT real time). This can be done via the Task Manager> Details Tab> Right-click process > Set Priority.

giupy said:

This caused me to think about it for a bit and consider other options:

Do you have any sort of power saving options on?

How much RAM do you have? In theory when your system uses up its RAM and it doesn't have enough memory available, it writes to the page file on your system, if you have one. If not, it frees up some memory and writes into the RAM again. I don't know how that practically translates into the effect on sound, but in theory it could be responsible for underrun.


Additionally try setting your players priority to high (NOT real time). This can be done via the Task Manager> Details Tab> Right-click process > Set Priority.

Click to expand...

No power saving mode is enabled as far as I'm aware. I hate those things for reasons like these. Besides I'm running on a desktop, what power is there to save?

My specs as follows

Asus Z68-V Gen3
Intel i7 2700K 3.5 GHz
G.Skill 4GBx2 PC3-12800
Zotac GeForce GTX 970
Cooler Master Silent Pro 750W

I've had this build since early 2012, only the GPU was bought in 2015 when it first came out.

I get the popping noise even when there is no audio playing at all. In fact all I have to do is to switch the mode on my DAC to XMOS USB and I immediately hear it. I don't think the buffer has anything to do with that right?