Question re: B&K Ref 30 Pre-amp - optical audio to DTV HR-44 DVR

[Bezellcsg]

Problem: Ref 30 receives surround bitstream but only decodes to analog ProLogic. No digital surround processing

1. When DTV HR-44 audio set to PCM, Ref 30 shows ProLogic regardless of surround format it is receiving
2 When DTV HR-44 set to Dolby Audio, Ref 30 changes from ProLogic to DD ** but will auto revert back to ProLogic if pgm paused, reversed, etc. When play is resumed, no sound **

Desirable: Mode 1: I am assuming Ref 30 receives PCM bitstream and could decode surround to appropriate analog or digital formats
Less desirable: Mode 2: DVR Dolby Audio turned on - I assume then the DVR is providing the specific surround format. - i.e. Ref 30 routes what it sees

I'm an amateur audio enthusiast. Have had Ref 30 over 20 years, know the menus well. Core to the design is auto-detect surround bitstreams and route as per setup. Auto-detect is integral to the design and, unless you have very specific apps, cannot be changed - yet...not happening.

Separate digital audio input, similar issue with Roku except it never sees more than ProLogic - ever

??? Has the digital side of my trusty Ref 30 gone out?
??? Any explanation for revert from DD Surround back to ProLogic when pgm is paused (or channel changed etc) and the DVR has detected and is providing the correct Surround format? (and not the Ref 30)

I'm at a loss....any ideas are very much appreciated - THANK YOU

 

[Trebdp83]

If the DTV HR-44 is set to output PCM, it will output a two channel signal in PCM regardless of the actual audio track in play. The Ref 30 will use Pro Logic when selecting Surround mode to expand audio into additional speakers when playing two channel analog or digital PCM signals. If the DTV HR-44 is set to Dolby Audio, DD will be displayed as the incoming signal. The signals can be DD 2.0, DD 5.1 or even DD EX.

Whenever Pro Logic is displayed, it is referencing the current mode in use, not the signal. If it is displayed, you know it is working with a two channel signal or no signal at all. So, if pausing a Dolby Digital 5.1 signal and using Auto Surround mode, the display may go from Dolby Digital to Pro Logic.

The Roku may be set to PCM output as well rather than bitstream of audio track. The model of the Roku would be helpful here.

If you are using a 5.1 setup, you need to use Surround 5 at minimum. If you have a 7.1 setup, you need to use Surround 6.

 

[Bezellcsg]

If the DTV HR-44 is set to output PCM, it will output a two channel signal in PCM regardless of the actual audio track in play. The Ref 30 will use Pro Logic when selecting Surround mode to expand audio into additional speakers when playing two channel analog or digital PCM signals. If the DTV HR-44 is set to Dolby Audio, DD will be displayed as the incoming signal. The signals can be DD 2.0, DD 5.1 or even DD EX.

Whenever Pro Logic is displayed, it is referencing the current mode in use, not the signal. If it is displayed, you know it is working with a two channel signal or no signal at all. So, if pausing a Dolby Digital 5.1 signal and using Auto Surround mode, the display may go from Dolby Digital to Pro Logic.

The Roku may be set to PCM output as well rather than bitstream of audio track. The model of the Roku would be helpful here.

If you are using a 5.1 setup, you need to use Surround 5 at minimum. If you have a 7.1 setup, you need to use Surround 6.
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TYVM - your comments align to the testing (mode 1 and 2) I setup. Makes sense. I've owned the Ref30 since 1997 and use customer presets that respect Ref 30 5 modes. System was used for 18 years or so and recently taken out of storage and redeployed. Quick speaker setup and refresh of custom presets to reflect inputs, etc.

The behavior you described as what I expect - what's not making sense is the loss of audio when the signal is stream is paused (i.e. DTV pgm is paused, then started)

To look further, I set up 3 pre-sets all with Mode=Surround. 'SAT' uses Surround 6 (DD EX), custom preset 1 uses Surround 5 (DD) and preset 2 uses THX 7 to note any effects in processing. All demonstrated the appropriate signal during DVR pgm play but all displayed the same problem when pgm paused....

1. DVR is changed from PCM to Dolby.....Ref 30 responds and shows Surround 'X' depending on which preset....all is well....

2. then I pause the pgm....Ref 30 lights show Digital and Pro Logic - all is well

3. then I resume play....Ref 30 remains in Pro Logic, digital light is off, and there's no sound. The 'no sound' issue is baffling

Any ideas? Again, my thanks for your time and effort, much appreciated.

 

[Trebdp83]

When pausing and then restarting program, try a slight rewind when sound does not resume. Does the slight rewind get sound back on?

 

[Bezellcsg]

When pausing and then restarting program, try a slight rewind when sound does not resume. Does the slight rewind get sound back on?

Great idea. No change. Note another input is Surround 6 for Blu Ray and works fine..(I see DD, DD EX and DTS).so I'm wondering if this is a timing/handshake issue between Ref 30 and DVR 44? Both are old....current audio connect is optical...I have a digital audio cable for component I could easily try....whadds ya think? If its handshake/timing, maybe component is more tolerant? Also don't find dvr44 manual online - no idea if bugs exist...

 

[Trebdp83]

I’d try the digital coaxial connection to see if it does any better at all. If no change, I’d leave it at PCM. When Dolby signals are not flagged using PCM, Dolby offset won’t dial things down and lower volume output. So, while the PCM signal will be two channel and require Pro Logic for surround sound, it may actually sound better and/or louder than a DD 5.1 bitstream at the same volume level. Results will vary of course.

 

[Bezellcsg]

Agreed and TYVM for your interest/help. System will be used in secondary room, currently planned for use in a separate building used as a work shop/sports retreat....thought it would be nice to get the 'ole gear up and running. Seems fine, actually, Blu Ray stuff works fine. DTV isn't long for our world - we just got up on Starlink and are gradually shifting to streaming. Thanks again!