SMSL SU-8 pops and clicks on track format change

[Dnmtsn]

I am opening this thread with the sole purpose of reaching a solution to this without clogging the main thread for this device https://www.audiosciencereview.com/forum/index.php?threads/smsl-su-8-version-2-balanced-dac.5433/

So far to me it seems that it is a problem with how the device works with Windows sound drivers.
Since several members on the original SMSL SU-8 thread claim they DO NOT have pops and clicks and I have no reason to not trust them, I start with the presumption that there must be a certain configuration where the problem is solved.
Here’s what I tried so far without success:
- No windows intervention, just native win sound drivers - the device is seen by both Windows and Roon and can play music, but it clicks between tracks when format changes.
- XMOS driver installation from the manufacturer page http://www.smsl-audio.com/download.asp
The SU-8 driver is on the second page, 4th from top. However for me this didn’t even install - installation stopped in the middle and it left the driver hanging somehow because after windows restarts it did not even see the DAC at all.
There is an XMOS driver on the first page, also 4th from top and this seems to be the same thing as the one marked as being the SU-8 driver but a newer version. I was able to install this, the DAC is now seen by both Windows and Roon and Roon sees two versions, an ASIO and a WASAPI one.
So with these drivers installed, when using the ASIO drivers in Roon the DAC produces the same clicks and pops when format change. When using WASAPI in Roon it will simply not play anything that is not red book.

NOw, many members in the original thread suggested that WASAPI must be set to exclusive mode and then the clicks will disappear.
I can say two things about this - Roon has this application exclusive mode enabled by default, and it reports it as such in the signal path, so in Roon the device has exclusive access to the WASAPI driver if I understand this correctly. I’m not sure if this is the exclusive mode required though, because there’s another setting for WASAPI exclusive mode under windows sound settings/device properties/advanced and there is a checkbox saying ‘Allow applications to take exclusive control of this device’
Presumably when this box is UNCHECKED the WASAPI exclusive mode is activated.
The problem is once this is activated ROON will not play ANYTHING. It will just skip through the tracks for a while and then it stops with the announcement ‘Too many playback errors’
So all solutions proposed and tried so far not only fail to solve the problem but actually make it worse.

To test the hypothesis that this is a windows problem I fed the SMSL DAC from a Raspberry Pi streamer using Ropieee and indeed the clicks disappear!
For analog out I am using XLR into powered speakers/sub (ADAM T10s/T5V). I am not able to test RCA out as I don’t have long enough cables.
I also tried optical out from my PC but I must be doing something wrong there as windows/Roon doesn’t even see the device...

I might have misunderstood things, or used the wrong drivers or miss something important and here is where I am asking help from the members of this forum.
Thank you,
Dan

 

[jcadduono]

Well, if you have Roon set to use WASAPI Exclusive mode, and then you uncheck the box on Windows Sound Control Panel to "Allow applications (such as Roon) to take exclusive control of this device", of course Roon is going to throw errors. You just disallowed it from using WASAPI Exclusive mode. All that box does is prevent applications from using WASAPI Exclusive, and they will have to resort to WASAPI Shared mode.

The SU-8 AFAIK does click when the format changes. The members who do not have clicking probably:
A) don't have music in different sample rates
B) are not using WASAPI exclusive mode, so all audio is being resampled to 1 sample rate, thus it never changes

If you have it in WASAPI shared mode, then you're probably still bypassing Windows mixer, so if you are sending audio at a different sample rate than what Windows is currently using, it will probably get discarded and you will hear nothing.

My recommendation:
If you don't like the pops and clicks, just use a decent quality resampler and play all your audio at 48khz or 44.1khz (whatever you choose in Windows CPL) through WASAPI shared.
You're not going to hear any audible differences if your resampler isn't complete trash. I don't even think Windows 10's built in resampler is that bad, so go ahead and just use DirectSound.

 

[Dnmtsn]

@jcadduono

this is helpfully, thank you and what you say about exclusive mode is an eye-opener. How silly of me to not realize that but now it makes perfect sense

so basically this clicking on format change is a design error of this DAC.

I suppose Roon’s resampling algoritms should work fine for what you suggest... but I don’t want to do that even though I am sure it will sound just fine. I’m still not able to leave behind the placebo effect induced by seeing a high sample rate on a screen or coded in a led color... I’ll try to Live with it for a while and if I can’t stand it I’ll sell it.

 

[jnorris]

Using USB, my SU8 doesn]t click but there are a few dropouts when the sample rate changes. Using optical, sample rate changes are smooth and noiseless.

 

[Dnmtsn]

Using USB, my SU8 doesn]t click but there are a few dropouts when the sample rate changes. Using optical, sample rate changes are smooth and noiseless.

Thank you - which windows version are you running? also, are you using windows native sound drivers or did you install drivers from SMSL's page?

 

[jnorris]

I'm using Windows 10 version 1909. Running on USB, installing the SMSL drivers made no changes to the dropouts at rate change. On optical, there were no dropouts either before or after the installation of SMSL's drivers. I think those drivers only work with USB anyway.

 

[Dnmtsn]

while I have gotten used to the pops and clicks this DAC is now doing something else that is quite annoying so I'm trying to find a way to solve it or make a decision to replace it

on low volume it goes on standby - it doesn't display anything to say that it's on standby, but my ADAM T10S subwoofer which is the next component in the chain goes on standby and it does that because it does not receive a signal from the DAC.

The other thing, that I think is related to the first one, the DAC disappears from Roon completely at times. I mean, it is not even visible as an audio device that needs enabling, so it does not appear to be connected to the computer at all. I have to restart it by unplugging it to get it to show again in Roon.

Any thoughts?

 

[jnorris]

while I have gotten used to the pops and clicks this DAC is now doing something else that is quite annoying so I'm trying to find a way to solve it or make a decision to replace it

on low volume it goes on standby - it doesn't display anything to say that it's on standby, but my ADAM T10S subwoofer which is the next component in the chain goes on standby and it does that because it does not receive a signal from the DAC.

The other thing, that I think is related to the first one, the DAC disappears from Roon completely at times. I mean, it is not even visible as an audio device that needs enabling, so it does not appear to be connected to the computer at all. I have to restart it by unplugging it to get it to show again in Roon.

Any thoughts?

When plugged into the USB on the computer, the SU8 just shows the last sample rate used when the computer is turned off, it never goes into standby. When plugged into the optical output of the computer, the SU8 shows "no sig" when the computer is turned off, and again never goes into standby. By the way, there are no clicks and pops from the DAC when changing sampling rates when the optical cable is used instead of USB.

I suspect either a faulty SU8, or a problem with the computer it's plugged into. Also, where are you turning down the volume? You should leave the computer's volume at 100% and turn down the audio volume either at the SMSL or the amp or preamp it's driving.

 

[Dnmtsn]

I don't know... I use mine connected to computer via USB and it displays "USB DAC", or the name of the selected input.

I control volume from the computer because I couldn't train the Harmony hub remote to control the SMSL-SU8 (will have to try again) and the amp has no remote. Maybe this is the cause? If the computer sends a low volume signal the DAC "thinks" it has no signal so it sends nothing to the sub, which then goes on standby?

 

[jnorris]

You can tell the SU8 what to display - it's one of the settings. I told mine to display the sample rate. As for the Harmony, I have an older 600 model remote that I was able to get to work with the SU8. Remarkably, I also got it to work with the Schiit Saga preamp.

The lack of signal, or very low signal is probably causing the DAC to go to standby. I suspect your USB port isn't acting naturally, though. I might suggest a passive analog volume control like the Schiit Sys or the Mackie Big Knob to control your volume.

 

[Dnmtsn]

So I changed the setup to control the volume from the SU8; the PC is maxed out. I thought this solved it, but it only took a longer time to do the same thing - it still goes on standby at low volume. It's possible that this is the Sub's fault - if it gets a low volume it may sense it as no signal and go on standby - have to check with the manufacturer

 

[Dnmtsn]

hi friends, I have to ask again for some help with this DAC.
This time I am trying to get sound our from a PS4 Slim - which unfortunately only has HDMI out, no other digital sound out, so to get sound out to my powered speakers via the SMSL dac I am trying to use an HDMI extractor that has an optical SPDIF out. I thought that would be useful because only the optical in is available on my SMSL-SU-8.
So I'm going PS4 HDMI Out - HDMI extractor HDMI in - HDMI extractor Optical SPDIF out - SMSL-SU-8 optical SPDIF in.
But it doesn't work - I get stuttering sound. I even returned the HDMI extractor and got a replacement unit thinking it might be defective, but the replacement does the same stuttering.

So I will try another cable, but I need to buy one first.

Until then, is there anything that I may be missing regarding some possible setting of the DAC or the PS4? I went through all of PS4's sound out as well as through all the DAC's settings that I could find with that ridiculous remote control but nothing helped.

So, other than bad cable any other thoughts?
Thanks a lot.