Modularizing an AVR with separate components?

[anphex]

Hey everyone,

because of the current state of AVRs regarding HDMI ports or the lack of those and the high price for processors I was playing with the thought of ditching a preamp completely and building some kind of an own processor by wiring single components. For example a HDMI board that only routes the video and splits the audio to a DAC. This DAC sends it to my amps. So the best case would be having only two components. What do you think about this idea? Is this feasible with high quality parts that don't cost as much as a Dacia and don't require soldering and lot's of DIY?

My dream setup would be a HDMI 2.1 board with at least 4 inputs and 1 output, a digital audio or XLR output for the selected HDMI input to a DAC (also preferrably with XLR inputs and ouputs). No fancy stuff like frequency correction, EQ, wifi or bluetooth needed.

 

[Kal Rubinson]

How will you deal with the various audio codecs?

 

[anphex]

How will you deal with the various audio codecs?

Good question! Another thing I didn't think about.

Now after arriving at home from work an looking at my TV I wonder if I just couldn't use the inputs of the TV and use eARC from my LG CX given that the channel bug was fixed now. A few months ago there still was the issue that the HDMI inputs of LG CX would only recognize two channels instead of 7.1. Then I'd need only a DAC with eARC input. A weird breed, but maybe not as rare as a unicorn.

Edit: Ok, well you find plenty of those cheap stereo DACs online but I'd like to have something with more channels and a not-so-cheap converter chip for the outputs.

 

[Koeitje]

Can't you just do what you want on a PC?

 

[anphex]

Can't you just do what you want on a PC?

If my goal was using just my PC, basically yes. I could use an USB interface, set up my channels via driver and that would be the end of it. But I want to have the option of switching between multiple devices like gaming consoles, TV eARC...

 

[abdo123]

Just use the optical out/headphone out from the TV till the next gen AVRs are released.

AVRs are computational beasts and I don’t think you can get close to anything they achieve on your own.

 

[Weeb Labs]

Have you considered something along the lines of my AVR I2S modification? That would enable you to take almost any cheap or used AVR, handle all of the essential DSP internally, route the output channels to a couple of ADAU1701s via I2S for volume control or DRC and then out to DACs of your choice. You could even retain volume control directly via the AVR by looping one of the ADAU's auxiliary ADCs through its digital potentiometer.

 

[abdo123]

Have you considered something along the lines of my AVR I2S modification? That would enable you to take almost any cheap or used AVR, handle all of the essential DSP internally, route the output channels to a couple of ADAU1701s via I2S for volume control or DRC and then out to DACs of your choice. You could even retain volume control directly via the AVR by looping one of the ADAU's auxiliary ADCs through its digital potentiometer.

ugh that's some really valuable content! (and potentially illegal ).

Are there similar boards that would do AES output instead?

 

[Weeb Labs]

ugh that's some really valuable content! (and potentially illegal ).

Are there similar boards that would do AES output instead?

The WM8804 board that I chose actually outputs both SPDIF and AES (balanced SPDIF).

 

[audio2design]

I can get 5 HDMI inputs on a $250 AVR. If I want pre-outs yes I pay more. If you need more inputs, get an HDMI switcher for your least units inputs. You may have a solution in search of a problems. Rearrange the problem and it goes away.

No fancy stuff like frequency correction, EQ

What some consider fancy, others know is almost essential to a good home theater setup.

 

[markb]

ugh that's some really valuable content! (and potentially illegal ).

I wonder why that would be illegal? You’re not even intercepting the original encoded source stream at that point, it’s a decoded and processed version very similar to the analog version provided by the AVR, just a little less lossy.

The content production industry may not like it much, but that in my view doesn’t make it illegal. IANAL though.

 

[abdo123]

I wonder why that would be illegal? You’re not even intercepting the original encoded source stream at that point

Unless it's Dolby Atmos content, then you are intercepting the original source, just decoded.

As all (other) multichannel formats save the content as tracks per channel.

 

[markb]

Unless it's Dolby Atmos content then you are intercepting the original source, just decoded.

I don’t think so; it would be a decoded/processed version of the Atmos stream specifically for your speaker setup (distances, etc.), hardly usable by anyone else (without degradation anyway).

 

[abdo123]

I don’t think so; it would be a decoded/processed version of the Atmos stream specifically for your speaker setup (distances, etc.), hardly usable by anyone else (without degradation anyway).

I don't think you understand how the word unless works.

Dolby Atmos -> digital output doesn't reflect source material.

Every other multichannel format -> yes it does.

 

[markb]

I don't think you understand how the word unless works.

I do, unless used ambiguously

Dolby Atmos -> digital output doesn't reflect source material.

Indeed.

Every other multichannel format -> yes it does.

Even then there might be some delay/distance processing at play when e.g. Audyssey is used, but yes, we agree.