CEC DX51 digital to analog converter pops when music starts

[penmarker]

Hi everyone hope everyone is doing great.

I acquired this DAC and looking for a popping solution.
The right channel will pop whenever audio starts playing. It can be replicated by either play/pause or turning volume up from 0.

(Picture 1)
There are a pair of CHAMP Modules (red, horizontal with many LEDs) which I assumed was the cause. After swapping the cards the popping did not swap so it could be up stream.
The three boards (vertical) are Decoder board, Digital Filter board, and DAC board.

(Picture 2)
The dac uses 4 PCM1704 chips.
No service manuals are available and information is sparse.

The DAC board also has 2 kinds of tantalum caps. One is marked 47 10V. Another is marked 47 10g.
What does the g stand for?

Aside from the popping and slightly higher noise floor compared to modern DACs, it sounds good.
Need some help to nudge where I should start prodding.
Pop appears on both hot and cold out. RCA and XLR both pops

[penmarker]

A quick update.
I bought myself a Hantek DSO2C15 and wanted to see the turn on pop and I see this.
At first I thought it was a DC offset but actually no it’s full on distortion at start.
Whew it’s been a year and I still don’t know what’s going on with this thing.

[m k]

If 10 is voltage 'g' can be tolerance.

For noise,
digital side can flip over and put nothing to max.
Analog side can be a missing filter.

Speed up scope's time/div so that you can really see the noise.
Input same signal to both channels and start comparing.

Extension board would be nice.

If you can input bursts you can find a time window when pops start happening.
If bursts can't find anything the problem can be a muting system.

What hot and cold out means?

Are RCA and XLR only outputs?

Mainboard chips and transistors on the right are sort of extra.
Maybe some kind of output enable system.

Is the rightmost input side connector an RS-post, maybe a console of some sort?