Anthem STR Preamplifier: Producing audio artifacts under certain conditions (pops, white noise, and static)

I have an Anthem STR Preamplifier that has a built-in USB DAC (XMOS USB Audio 2.0 ST 308F). I have a Sonore microRendu (software version 2.6) feeding the USB input on the DAC. Anthem represents that the unit accepts native DSD, but if I setup the microRendu for native playback, DSD is no longer an option in Roon’s audio setup and it converts the DSD to PCM. If I select DoP in the microRendu, DSD is available in the Roon Audio setup and DSD tracks are not converted to PCM.

If I put together a playlist and the signal transitions from PCM to DSD, there is no issue. However, when the signal transitions from DSD to PCM, I hear a loud pop. Loud enough that I am concerned that it could harm my speakers.

Is there any way to remedy this issue?

Download the XMOS driver from www.anthemav.com.

  • Extract XMOS-Stereo-USB-Audio-Class2-Driver.exe to Desktop and double-click it.

I don’t think I can install the driver on the microRendu.

To try to circumvent the loud pop issue that I am getting when the files switch from DSD to PCM during playback, I began using the Sample Rate Conversion Filter.

I set it up to convert all files to DSD 128 which is supported by my DAC (Anthem STR Preamplifier) and the DAC is being fed by a Sonore microRendu. At first everything was fine. I listened to a playlist for about an hour and everything sounded great. However, when I started a new playlist I got nothing but white noise / static through my speakers.

I can fix it by powering down and starting over. However, I was hoping there is a better solution.

Hi @asiano ---- Thank you for the report and sharing this feedback with us. The insight is very appreciated!

Moving forward, I saw that you had opened two different threads on the community site pertaining to the Anthem STR Preamplifier. Being as both reports are concerning the the same device I have went ahead and consolidated your posts here so we can address these behaviors you are currently experiencing with the STR.

To help aide in our evaluation may I very kindly ask you to please provide the following:

  • Please expand on the description of your setup using this link as a guide.

  • Please provide screenshot of…

    • The playback settings you are using in Roon via the “device setup” window when you notice these audio artifacts (i.e pops and white noise/static)
    • The playback settings being used on the MR via sonicorbiter.com
    • The signal path leaving Roon when the errors occur.

-Eric

Hi @eric - I hope this includes all of the information you requested, but if you need anything else, please let me know. Thank you for combining the threads and helping me with my issue.

Roon Version:
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Windows Version & Basic System Information:
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Drive Specifications Where Music Is Stored (on same machine as Roon):

Collection Size:
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microRendu Settings:
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Device Setup microRendu & Anthem STR Preamplifier (set delay to 100ms to try to eliminate pop to no avail):

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DSP Settings Enabled = White Noise / Static Result:
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Roon Signal Path During White Noise / Static:
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DSP Engine Disabled = Result Loud Pop transition from DSD to PCM:

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Roon Signal Path Lod Pop (Difficult to get exact moment, but as pop occurs it is transitioning from what you see here and what appears on next screenshot):

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Hi @asiano ---- Thank you for the follow up and providing the requested information. Both are very appreciated!

Continuing forward, since noticing these behaviors with the STR have you tried temporarily bypassing the MicroRendu and attaching the device to a laptop or desktop computer acting a Roon remote to verify if you get the pops/static?

-Eric

Hi @eric - I tried that last night and it appeared to work fine. I didn’t get any pops when transitioning from DSD to PCM. I also tried the Sample Rate Conversion to DSD and there were no issues in my limited testing. I included some pictures below during playback.

How should I proceed going forward? I’d like to continue using the microRendu, but not with the popping and static issues. Would I experience the same popping and static issues if I build a Roon ROCK system?

Hi @asiano ----- Thank you for giving the proposed test a go and sharing the results with me. Appreciated!

Based on this observation you have made this feels like this is occurring because of the interaction between the Anthem + USB + Linux. If that is indeed the case moving to ROCK will not fix this behavior. I did some searching around which included checking Anthem’s website to see if there was any mention of how these device work Linux. Unfortunately I wasn’t able to run anything down.

I did chat with our tech team about this behavior you reported this morning and they suggested trying to start at a high resync delay value (3000ms) and increasing from there to see if the behavior improves.

-Eric