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KD-77AG9 / STR-DN840 - Keeps using only 2 channels...

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ant3110
New

KD-77AG9 / STR-DN840 - Keeps using only 2 channels...

Hello, 
I have hooked my KD-77AG9 to my ST-DN840 (via HDMI).

I have the following devices:

- Sony Blue-Ray player

- Virgin cable box

- NowTV stick

I want to connect these devices to the TV inputs so I can switch sources using the TV remote. The HDMI connection operates my DN840 amp and so auto switches it on with the TV and can control volume from the TV remote, so I do not need to use the amp remote at all - which all works as it should. 
The TV shows the audio format as 'Dolby Audio' for the devices connected. 

The issue is the decoding the amp is doing. The amp is set to "A.F.D. Auto" which should decode whatever the original audio is. When I change a source on the TV, the amp auto detects the audio stream and sets accordingly. However it only sets it to 2.0. So for example, the Virgin box audio output is Dolby - the amp shows "Dolby Digital +" however the output is only on the front 2  main speakers (2.0). If I manually adjust the amp surround mode to something else, eg. 'HD-D.C.S' or 'MULTI ST.' then I do get audio from all speakers (5.1).

But this is not Dolby. If I connect the Blue-Ray or Virgin box DRIECTLY to the amp (with HDMI) then it decodes correctly, Dolby is shown on the amp display and it arrives to all speakers (5.1). 

But using the TV to route the peripherals, the amp shows Dolby on the display but only arrives at 2 front speakers (2.0). 

Hopefully I've explained this clearly. 
Any advice would be appreciated. 


Ant.

 

 

 

 

3 REPLIES 3
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royabrown2
Hero

@ant3110 

 

This sounds as though you have the TV set to PCM instead of Bitstream.

 

This means that the TV is decoding the audio, instead of passing it on unchanged for the amp to decode, and PCM decoding results in the signal being busted down to 2.0 stereo.

 

I’m not sure where the requisite setting may be on your TV, but have a hunt for Bitstream and PCM in your audio settings, and see if you can toggle Bitstream on.

 

Bitstream is mentioned for the Optical Out, but you are not using that; however, this might be relevant:-

https://helpguide.sony.net/gbmig/C5311001/v1/eng/c_extsnd_ht.html

depending on what options you get in there.


My favourite bedtime reading is a Sony product manual…
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ant3110
New

@royabrown2 

Thanks for the reply. 

The sound settings on the KD-77AG9 in the 'digital audio out' only has 'Auto' or 'PCM' - it is set to Auto. 


When looking on the source select screen on the TV, the connected inputs show "Dolby" for the detected audio. 

 

I assumed it was outputting the correct format as it shows up on the Amp as "Dolby D+ but only as 2.0?
I don't think it's the amp settings that is at fault as connecting a device directly to the amp via HDMI results in the correct output. 

I am going to get an optical lead and try using the optical digital to connect the TV to amp, see if that changes anything. 

Ant. 

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Pentium_Gladio
Specialist

Hi,

 

Have you tried a different HDMI cable? Also, does this happen when you use an optical cable?

 

What is the software version of the TV you are using? You can find it by pressing the help button- Then select system information.

 

Also, in the digital audio out, there should be an option for auto 2 and auto 1. Did you try the Auto 2 option?

 

Regards,

Gladio