Article: Variations on a Theme: Budget Basement Entertainment System

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8 hours ago, bobfa said:

The Little SMSL DAC has a problem that is bothering me.  When you switch inputs and switch back to USB something happens to the DAC and it gets out of sync with my Raspberry PI streamer running Roon Bridge.  The DAC shows 512 in the display.  Then I have to go into Roon and re-select the proper output and TURN THE VOLUME way done to avoid a terrible speaker pop.  

 

Also, the bit rate display is nice, but volume is much more important to me.  Somehow I really need to see both!

 

More to come.

 

I had a listen tonight using my Raspberry Pi Ropieee streaming from Roon and can confirm that there is a pop with that when DAC first turned on. I believe this is because the default the DAC ends up with is to DSD512. So when I play something more typical like PCM 44.1, that switch from DSD --> PCM results in the "pop". 

 

This noise does not happen when I stream over my Windows RoonBridge (eg. the fanless MeLE PC) as a WASAPI device. I see there's a handshake sequence and the DAC defaults at start up to PCM.

 

Will need to play with RoPieee a little more and see if there's a way to make this act more gracefully!

 

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Played around with this some more. It looks like once the initialization with 1st playback happens with that pop, things are smooth thereafter. Switching between PCM <--> DSD doesn't result in the noise. So it looks to me like it's an issue with the Linux driver initializing the DAC. Maybe this would not be a problem if the SMSL DAC defaulted to PCM rather than DSD512 from the start (I suspect this is something they can do with a firmware update).

 

A suggestion until a more graceful solution is found for the popping, @bobfa...

 

Put the SMSL DO100 into UAC1 mode. In Linux, when turned on, it'll default to PCM 96kHz. No popping. In Ropieee, I can confirm it'll stream 44.1/48/88.2/96 properly. Obviously will be missing higher PCM sample rates and DSD, but at least no panic attack or worries about blowing speakers!

 

BTW: Anyone know who to contact at SMSL for issues like this? John Yang at Topping has been excellent to connect with for tech issues like this... SMSL needs a similar contact!

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4 hours ago, bobfa said:

I have not contacted them yet.  Also it happens when you switch inputs. and come back to USB.

 

Right, I see this every time the USB loses contact with the Pi, it defaults back to DSD512...

 

Sent a message to Mandy:

Quote

 

Hello Mandy,
I wrote a review series on the SMSL DO100 recently and showed that it performed very well!

 

It was brought to my attention that when the DAC resets and is connected to a Raspberry Pi (running Ropieee, Volumio), it "pops" when you first play music. (Also happens when changing input and coming back to USB.)

This appears to be because the DAC defaults to "DSD512" on start up and typically when we play PCM, that transition from DSD --> PCM will cause the noise. Can you ask the technical team to evaluate this because that popping sound is quite jarring and may even damage speakers if using this as a pre-amp.

Perhaps the DAC can default when starting up into one of the PCM modes (firmware update?)? I noticed that putting the DAC into UAC1 setting does not have this problem but of course we lose the ability for 24/192+ and DSD playback.

Thanks,
Archimago
archimago.blogspot.com

 

 

Let's see what the technical support for SMSL looks like!

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9 hours ago, DuckToller said:

Small update:

While in comms with Polly from hifi-express.com for another project, where I referenced the DO100 discussion here,  she mentioned to me, that your request was forwarded to the engineering  department and that a firmware update should fix the problem.

Waited 2 days to see if you got that answer as well.

Best, Tom

 

Nice, I logged into ASR tonight and saw the message...

 

Let's hopefully see the firmware soon! Especially for a hobby like this where the community isn't very large, and many of the companies are in China, customer support goes a long way towards developing positive sentiment.