Optical audio problem

[mid_gen]

Stumped with this one.

I've got an Optoma UHD300x. I feed it from a Virgin TV6 box, and I run an optical cable from the projector into a Fiio D3 DAC and then into my Naim Bait 5i.

This all worked fine for months.

Now the audio has started crackling. The 'locked' light on the Fiio flickers.

I have :

Replaced the HDMI to the projector. Still crackles. Not the cable.

Added a HDMI audio splitter to isolate the projector. So the audio is split before it reaches the projector and goes into the Fiio. Still crackles. So it's not the projector.

Replaced the optical cable. Still crackles. Not that cable.

Plugged the optical out from my Arcam CD62 into the Fiio. Works fine, no crackle. Not the Fiio.

Plugged the Virgin box straight into a TV. Works fine, audio, no crackles. Not the box.

I don't know what else to try

 

[mid_gen]

Using the analog out from the HDMI audio splitter now and that works fine. So maybe it is the Fiio...hmm.

But it works fine with the CD player optical input...

 

[jpaul]

sounds like jitter on the optical output from the hdmi splitter and optoma that the Fiio is not able to compensate from, could you reduce the bitrate on the sound to see if it crackle stops, this is a problem with chromecast audio optical output.
Does the fiio have a good quality power supply, or, are there devices running off of poorer usb supplies. ?
Have you tried really reducing the hdmi cable length from the virgin box.

edit : see https://www.audiosciencereview.com/...ents-of-chromecast-audio-digital-output.4544/

3. The Chromecast output has more jitter than an audiophile/instrument grade Toslink output. This is evident when used with low quality DACs like Schiit Modi 2 Uber.

4. Using a well-designed Dac like the Topping D50, there is no difference at all between Toslink from Chromecast or higher fidelity sources. All the jitter is filtered out resulting in the performance of the DAC itself being the limit.

 

[mid_gen]

sounds like jitter on the optical output from the hdmi splitter and optoma that the Fiio is not able to compensate from, could you reduce the bitrate on the sound to see if it crackle stops, this is a problem with chromecast audio optical output.
Does the fiio have a good quality power supply, or, are there devices running off of poorer usb supplies. ?
Have you tried really reducing the hdmi cable length from the virgin box.

edit : see https://www.audiosciencereview.com/...ents-of-chromecast-audio-digital-output.4544/

I get the same jitter from both the audio splitter and taking the output from the projector.

Of course it's possible that the Virgin box is knackered in some way.

I'll try the Fiio on another device....

Edit - I have tried the Fiio on a different power supply...