HELP !! Getting " Clicks " when using sPDIF coax digital out

[arupg]

Am getting very disturbing CLICKS into the speakers when the Sony Blu-Ray Player BDP-S370 is used as a CD Transport - connected to Audio Alchemy DITB dac via Theta TLC Jitter attenuator. This happens when the Transport is either:

1. Switched ON or OFF

2. The Disc drawer is Opened or Closed while changing discs.



Sony Blu-Ray - - - > Theta TLC - - - > Audio Alchemy DITB dac

The entire digital feed is RCA coax 75 ohms.

Pasted below is Sony Blu-ray sPDIF schematic.

Help will me most appreciated. Unfortunately the Sony Blu-ray is a complete SMT.

Thanks in advance!

An externally hosted image should be here but it was not working when we last tested it.

 

[Mooly]

It doesn't sound like a "fault" in the hardware sense... what you describe points to the data stream being corrupted/switched off and back on etc as the drawer opens and the disc is removed.
I don't know if any standards exist for provision of muting when the data stream is lost... and how the receiving DAC deals with that. When you power off the data will I suspect just dissapear unpredicatably... and the DAC gives a momentary glitch... and same on power up as the data appears.

 

[arupg]

You are quite right that the Data stream just blanks off - hence the "annoying clicks". The Theta jitter attenuator & the DAC uses the standard receiver - i.e. CS8412 via the 74HCU04AP which would be the PLL.

Now say there was a Muting circuit on the Sony Blu-ray player's sPDIF, would that have rescued me from these noises?

 

[arupg]

I do see a Muting circuit on the sPDIF.

The portion boxed in RED

An externally hosted image should be here but it was not working when we last tested it.

In more detailed form Here below :

An externally hosted image should be here but it was not working when we last tested it.

 

[Mooly]

Hard to say, pin 11 obviously gets pulled low during mute... does it just kill the data stream though, or does it send some info into the spdif.
You could try pulling pin 11 low and seeing if the clicks appear. Be interesting to scope the spdif and see what the data does in mute and unmute.

 

[arupg]

Hard to say, pin 11 obviously gets pulled low during mute... does it just kill the data stream though, or does it send some info into the spdif.

Its impossible to say if the data goes LOW or KILL unless traces seen via 'scope.

You could try pulling pin 11 low and seeing if the clicks appear. Be interesting to scope the spdif and see what the data does in mute and unmute.

The PCB is so densely packed with every conceivable sort of chipset that poking a nose may actually send it packing off to a trash can. These Sony units are so 'fragile' in their ESD behavior that honestly am a bit scared. The damn Blu-ray player is just 3-days old! 🙂

 

[arupg]

BTW - the data I doubt goes to KILL or else the following [ Jitter-att and DAC ] would loose the PLL LOCK condition which it doesn't - so must be the MUTE CKT playing up. (just my hunch though!)

 

[Mooly]

You could do with trying another player, and also trying feeding this one into another DAC of any sort, Mini Disc recorder etc.