DCS Bartok - Popping noise on some network inputs

Support
1

Hello DCS Community,

I’m experiencing the following issue with my setup, on all network inputs except Spotify, I experience a popping sound frequently.

Here’s the setup details: (Note we’re mid upgrade and just did speakers)

Wadia Transport
DCS Bartok DAC (No Apex yet)
Classe CA-200 AMPS
Wilson Audio Alexx V Speakers

Network side:
Ubiquiti edge switches
Ubiquiti agg switches for core
TrueNAS for data
Proxmox HyperVisor with various VM running streaming apps (Subsonic, Jellyfin, etc)

I’ve gone through the various information on the network and DCS Bartok side, such as log files, switch port errors, etc. Nothing to report at all.

Spotify streaming works great, no clipping, no popping, 0 issues other than lower than optimal quality.

Qobuz, Tidal, and AirPlay sources (Subsonic, JellyFin, etc) all generate popping sounds very frequently.

Any ideas, input, etc would be appreciated.

For background I’m an experienced engineer (AI, Cyber, Technical Operations, Network Engineering, etc) and I’m more than glad to do whatever troubleshooting is required even if packet captures or something complicated is required.

Thank you for your time and consideration.

Looking forward to the Apex upgrade and maybe a Rossini Apex soon!

2

Is the popping sound related to the music playing, pops on the rhythm of the music, the base, loud passages? Or is it random?

How is the output voltage set on your Bartok? 0.2 - 0.6 - 2 - 6V?

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3

Hello Ermos, thank you for your reply.

The popping sound is random and present in every track.

I’ve tried with 0.2, 0.6, 2, and 6 volt and it’s still present.

The primary listener in my household prefers it at 6V.

We’re not using a pre-amp.

Thanks!

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4

Your welcome. I just try to figure out what is happening, so I tried to find out if your popping is clipping.

First: the input sensitivity of your Classe CA-200 is: 1.3V. So I would not output your Bartok higher than 2V. At 6V you are prone to clipping very easily. That it does not happen with Spotify might be because it is not high resolution material.

But your popping is random, as you say. Since your Classe is a bit old, that might be the cause, having difficulties with dynamics, or a problem with its power supply capacity: leaking capacitors.

Popping is almost always an arcing problem. The high voltage in the amp has found some path that cannot stand the high voltages and discharges suddenly through that path. The arc current is high, but cannot be sustained by the power supply, so the voltage drops a little, the arc extinguishes, and it takes some time for the power supply voltage to build back up to where the arc will start again.

I don’t see a reason why the network input might give you pops.

But let us see what dCS support says, and once again call in the magic @Phil

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5

Thank you so much Ermos, I’ve argued about the line voltage and also suspected the Classe CA-200 as the culprit, it makes a lot of sense given the equipment age.

Really appreciate the insights!

Yea I agree, it’s odd that only some network sources are affected, I think it’s related to the quality of the input as suggested.

2 Likes
6

Interesting setup. You didn’t mention if this exact setup was previously working fine and the problem only just started happening?

My initial wild guess would be your Proxmox as the likely culprit where the problem lies. Did it ever work properly? If so, what’s changed?

Mind you, I’m not suggesting that Virtualisation is inherently the problem, in fact, I have a UPnP Server running on an ESXi VM which works just fine. Just that when there are drop-outs or popping in music playback, it’s usually the software source of the data-stream, rather than any hardware-wired element.

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It appeared to be working correctly with the previous speakers.

Since we’ve gotten the new speakers, it’s become evident with sources other than the Transport and Spotify.

Interesting idea, I will try running the software on a spare NUC instead of a VM on Proxmox.

Thank you!

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8

I guess the speaker change might have disturbed something else in the chain?

One additional question, which perhaps might confirm Proxmox as the likely culprit; You mentioned Spotify works great, was that Spotify Connect? If so, Spotify Connect streams flow directly from the Internet to the Bartok, Promox would not be part of the chain.

What about your Qobuz/Tidal streams? How are you connecting your Promox/Jellyfin to the Bartok; via USB, or Ethernet UPnP Control? (I’m not that familiar with Subsonic or Jellyfin :thinking:)

9

Sorry for the delay - I’m here - let me have a read!

(Thanks for tagging me @Ermos !)

Phil

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10

Does this also occur on Internet Radio? (The reason I ask is because Internet Radio streams are usually very bandwidth limited and have very low data rates - like Spotify - but has a similar path to Qobuz and TIDAL into the Bartok.)

(Spotify is supported by Spotify Connect and has a different route into the Bartok.)

When you are using TIDAL and Qobuz is that through the Mosaic app?

OK - this is really odd as Airplay is / has a totally different signal path to Qobuz and TIDAL but is generally a higher bitrate than Spotify so my gut feeling here is we’re hitting a bandwidth limitation somewhere - especially if Internet Radio works OK when you test it out.

Is your Ubiquiti kit all hard wired end to end?

Are you using any Ubiquiti AP’s configured as a mesh to extend your network?

Which edge switches and aggregation switches are you using?

Cheers

Phil

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11

Hello DCS Community,

I wanted to follow up, my apologies for the delay, home construction and upgrades.

We upgraded from the Bartok DAC to the Rossini APEX DAC.

All issues have gone away for now.

I still haven’t had a chance to visit my Colo to remove a spare computer for testing streaming without a virtualization layer.

Will update as things progress.

Thank you for your input!

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