Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems 861 displays PCM when connected to Vertex2

Sounds as though you are not decoding to PCM at source properly - that is, if you are seeing AC3, then this is bitstream passthrough. If you are trying to use the HD621 to full effect, your need to be forcing the sources to send PCM rather than bitstream. The HD621 will not decode any audio, it will simply extract the PCM audio or passthrough the AC3 if you have selected that as an option.

My suggestion, if you have not already done so, is to hard code the HD621 to the audio type you wish to receive and then ensure that the sources can generate the required PCM output. Once that is working, by all means then re-enable the bitstream passthrough should you also want / need that capability.

This is how I currently have things set up:

Input 0 - Samsung CMT-5320 Cable Box
Input 1 - ATV4
Input 2 - PS5
Input 3 - Intel NUC (running Roon Bridge, endpoint for multichannel audio)
TX0 - Samsung Q90 (4K TV)
TX1 - HD621

Cables are all 2.0/18Gbps. I am running TX1 to the HD621 because of the post from SamuelVelma in this thread noting that this gave him a MHR readout on his processor.

Maybe I will try the audio output instead of this next time I give this a whirl.

Right now I do not have TX0 going to eArc port on the TV, something I can certainly do, but I like having audio available at the TV without the surround system being on, and when you enable the eARC bypass you lose audio at the TV.

I am not running apps on the TV and all inputs are hooked up to the HD621 through the Vertex2, so I don't really need to fetch audio from the TV.

If you're using TX1 for the HD621 you will not get anything from arc/eArc. That link for audio only goes to Audio Out. I.e. Arc/eArc enabled or disabled won't matter with this setup.
You will instead get whatever is coming in on the HDMI port you selected. So you cannot get audio originating from the TV (internal apps) with this setup.

I forget what the ATV audio output options are, I suppose mine is probably set to audio.

That said, I don't think you need to worry about the processor being befuddled by 7.1. The HD621 can actually pass 8 channels via 4x coax outputs, so in my case I just have three of the four outputs connected to my G61 using short RCA cables (6 channel MHR coax connection). The G61 sees six channels of audio (5.1) and is not confused. But I suppose if you are only picking off 5.1 out of 7.1 maybe you are missing out on some sound (not even sure what 7.1 adds to 5.1, sides?).

Good info I think. I will revisit options for audio output for my various sources, and also my HD621 settings. The former are largely pretty limited I think, but I should at least know what they are …

Good point. Since I am not getting a MHR connection any more (and even if I was not sure what that gets me that PCM does not for sources I have) might as well try the audio out on the Vertex2, and might as well use the eArc input/output on the TV so if I do want to grab sound from the TV (without using optical) I can do so.

You probably have this correct but just to make sure. This is from the HD621 FAQ on how to configure and hook up the MMHR cables.

On the set-up program, under the “Audio” tab within “Properties” of the HD621, the setting “Linear PCM” should be set to “6 Ch.
Three digital interconnect leads should be connected between the two units. On the HD621, the outputs labelled “1/2”, “3/4” and “7/8” should be connected to the “L/R”, “C/LFE” and “SURR” input sockets respectively on the surround controller.

Thanks, I will definitely check this. If I was not looking at this I would probably connect to 1/2, 3/4, and 5/6!

In 6 channels, the active HD621 outputs are 1 to 6 ( it's my configuration and I have sound in surrounds...)

Without channels 7 and 8 (existing but not connected), you loose surrounds back of 7.1 signal but nothing of 5.1 signal.
In Meridian 5.1 configuration, default surrounds configuration is surround back but in reality it's sides (think theater)!
7.1 adds surrounds back at 5.1

That's what I did.

Is this wrong then? It's from Meridian HD621 FAQ.

I'm connected on my G68 with 1/2 3/4 5/6

When I check the channels with REW or Dolby Audio test, in LPCM 5.1, Channel surround right is in my right surround speaker...

But I know there are some files in 5.1 where surround channels are in the channels 7 and 8 : so in surround back. I need a remapping on my computer...
And it's also the Meridian logic : in a 5.1 system, for them, the (standard) surrounds are back. But when you have a 7.1 system in a 861v4 or G68, (standard) surrounds became sides and you add surround back.
For Dolby (think at a theater), (standard) surround is sides... And 7.1 add backs to the sides.