Adding post-DSP SPDIF outputs to AVRs

[Taso]

Most likely the gain differences of the AVR channels will be done via the analog volume control chips after the DACs. Maybe they also tweak the volumes control of the DAC a bit.. hard to say. You may find out with a bit of experimentation.


It’s fixed. Note though that the MiniDSP will resample it again to its internal clock domain regardless of the input sample rate.

Ok, thanks, I almost understand.
If you were in my place, with this audio scheme/chain, considering the Denon x3600h, with digital coax out at 48khz (I assume 24bit)...how would you set my Apogee Rosetta 200 converter at the input to the Denon? Also, would you run the 10x10 minidisp with 48khz or 96khz plugins? I attach a simple drawing.
Thank you

 

[Taso]

It is indeed a bit of both. The individual channel gain offsets are digital and then the analog volume control ICs are used to attenuate all channels at the output. Setting the system volume above ~82% will also raise the DSP output above 0dBFS, which is the source of the clipping often encountered during Amir's reviews.

Are you saying that, although in my system, the volume is regulated by the minidsp, even the original volume of the denon which, in my case, is useless and does not regulate anything, can change the digital output signal for me?
Would it therefore be a good thing if I kept it fixed at zero in my employment?
Thank you

 

[voodooless]

Ok, thanks, I almost understand.
If you were in my place, with this audio scheme/chain, considering the Denon x3600h, with digital coax out at 48khz (I assume 24bit)...how would you set my Apogee Rosetta 200 converter at the input to the Denon? Also, would you run the 10x10 minidisp with 48khz or 96khz plugins? I attach a simple drawing.
Thank you

I doubt it matters much, you’ll have 2 ASRCs, one in the x3800h, one in the MiniDSP. Given that same rate ASRCs are often the least ideal cases due to closeness of the clock speeds, you may be best off having the ADC and MiniDSP at 96 kHz. I don’t think it will be audible though.

 

[Taso]

I doubt it matters much, you’ll have 2 ASRCs, one in the x3800h, one in the MiniDSP. Given that same rate ASRCs are often the least ideal cases due to closeness of the clock speeds, you may be best off having the ADC and MiniDSP at 96 kHz. I don’t think it will be audible though.

OK, thanks anyway for the teachings and advice.

 

[fdiji]

Hello all,

Thank you @Weeb Labs for putting this all together. This is a potentially great solution to a problem I am currently facing specing out a HT in a condo with a pair of Active Bang and Olufsen Beolab 5's with Active Bass Control (ABC) for my for my FL and FR speakers. I know many may scoff at B&O, but these do put out a pretty impressive sound for movies with 2 15" woofers all in a beautiful package which was important to me for my condo's decor.

Each Beolab 5 can be fed a digital coax input but because the speaker applies its own "ABC" filters, I want to pull the signal from the decoder on the receiver rather than post DSP to avoid a double DSP scenario. I'd like to still apply DSP to the rest of the channels which will be a more convensional setup with typical home theatre speakers. Is this possible to do?

 

[voodooless]

Is this possible to do?

Potentially. The main issue is the lack of volume control on the makeshift SPDIF output. You’ll have to manually match the L+R to the rest every time. Also note that the room correction of the AVR may stilll be beneficial to the B&Os, because it does different things vs the B&O correction. I would always try them both first.

 

[fdiji]

I think that would be possible with a harmony remote integration as volume goes up by 1db per click, but those are valid points thank you. I'll report back if I decide to embark on this endeavour.

 

[Taso]

I don't understand how you can do it harmony remote....

 

[fdiji]

I don't understand how you can do it harmony remote....

The BeoLab 5’s have their own volume control via IR that increase in 1db increments so the harmony could control volume control of the AVR/Processor and Beolab 5 simultaneously

 

[toini]

Hi! I have a bunch of Genelecs (4 x 8341A, 2 x 7360A subwoofers) and am looking to add one more center speaker for a 5.2 surround setup. When setting this up I would like to avoid an additional analog-digital conversion and feed the speakers with digital AES/EBU signal. That should also allow reducing some cabling as you can pass two channels in one cable (e.g. left and left surround could go in one cable as well as right and right surround).

To grab the digital signals I'm looking to buy an inexpensive Denon such as the AVR-X3600H and implement this hijacking (as @Taso kindly demonstrated this should work well).

However, the SPDIF signal wouldn't do the trick for feeding the Genelecs. So I have two problems to solve:

1. I'd need AES/EBU instead of SPDIF. Is there a board similar to https://www.audiophonics.fr/en/inte...rs-spdif-bnc-wm8805-24bit-192khz-p-12561.html (for WM8805) that I could utilize here?
2. I would need to grab several channels, not only left+right. Could I just set up several boards? Will there be troubles with clock synchronization?

I think these both topics were briefly discussed by @Weeb Labs on the thread's first page.

Any advice appreciated!

 

[voodooless]

You realize that you will not have a way to volume control via the AVR? If you can do that via GLM, that may not be a problem.

You may just get away with using SPDIF coaxial. It should work with the Genelecs, you will need to test a longer cable run though. You can also find WM8005 boards with AES, they are less common and usually a bit more expensive.

If you get a service manual, you should be able to find all the signals you need.

Maybe a VanityPRO is a cheaper and more reliable solution if you have a device that can do the decoding (like an AppleTV).

 

[Taso]

Hi, I'm glad you've already received good advice. my modification works fine even though I'm selling the denon. I know you don't care, it was just to say! I'm moving on to something else. I had bought the x3600h service manual to be able to understand how to operate. Good luck!

 

[toini]

You realize that you will not have a way to volume control via the AVR? If you can do that via GLM, that may not be a problem.

Yep, I shouldn't need volume control in the AVR as I can do it with GLM (wouldn't mind that ability in the AVR, too, though).

You may just get away with using SPDIF coaxial. It should work with the Genelecs, you will need to test a longer cable run though. You can also find WM8005 boards with AES, they are less common and usually a bit more expensive.

Do you mean SPDIF with different voltage etc could be connected to the AES/EBU XLR?

Maybe a VanityPRO is a cheaper and more reliable solution if you have a device that can do the decoding (like an AppleTV).

I looked into that and it does look interesting. However, it's much more expensive than a used AVR-X3600H would be and, well like someone else with Genelecs points out in the thread it would be a bit insufficient for the usual use cases: https://www.audiosciencereview.com/...view-hdmi-audio-extractor.30440/#post-1069851

 

[Zooqu1ko]

However, the SPDIF signal wouldn't do the trick for feeding the Genelecs. So I have two problems to solve:

1. I'd need AES/EBU instead of SPDIF. Is there a board similar to WM8805 that I could utilize here?
2. I would need to grab several channels, not only left+right. Could I just set up several boards similar to WM8805? Will there be troubles with clock synchronization?

1. Maybe this thing from Audiophonics. The form factor seems more convenient if you need multiple. Passive converters such as these from Canare work pretty well for S/PDIF to XLR-based AES/EBU, I'm using them with my 8240s without issues.
2. There should be multiple, practically independent I2S busses, each carrying 2 audio channels, in your receiver, and you would link each one to a separate converter board. There's no reason to assume that all channels would not share a clock, but it really should not matter. Unless, of course, you were to use a 9301B, but I can't imagine why you would do that.

 

[voodooless]

Do you mean SPDIF with different voltage etc could be connected to the AES/EBU XLR?

Nope, just a simple RCA to XLR cable is known to work well with Genelec products. I would definitely test it out first though.

 

[MCH]

:

1. I'd need AES/EBU instead of SPDIF. Is there a board similar to https://www.audiophonics.fr/en/inte...rs-spdif-bnc-wm8805-24bit-192khz-p-12561.html (for WM8805) that I could utilize here?
2. I would need to grab several channels, not only left+right. Could I just set up several boards? Will there be troubles with clock synchronization?

If you are willing to, you can also build your own, will be cheaper than 30eur x n channels/2 and you can make it in a single board. You don't need wm8805, wm8804 is enough. For almost proper AES-EBU implementation see below, thought as others have said, it might work with an existing spdif anyways. Good luck.

Right AES/EBU to spdif schematics?

Hello, let's see if someone can help me to find the right schematics for AES/EBU inputs/outputs. What i want to do is to add AES/EBU inputs and outputs to a spdif transceiver chip (wm8805). I thought i could find what i need easily until i found this article, that seems very good but made me...

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