ASR Open Source Streamer Project

[anphex]

OK, let's talk specifics.

Sources
PC over USB: How many channels? What formats?
Optical input from TV and other consoles: Is this stereo? Or lossy DD 5.1 over optical?

Outputs
How many output channels?
What are you doing with FIR? If you have long linear phase FIR filters this can add large delays which are unsuitable for audio/video applications unless you have the ability to delay video.

Michael

Inputs:
PC over USB: Mostly stereo, sometimes 5.1 PCM for gaming (reduced to 4.0 by windows or my AVR since I only have 4.0)
Optical from TV: PCM stereo, pre-decoded stuff from Nvidia Shield (so also PCM), surround only supports lossy dd 5.1 it seems.
Optical from consoles: ditch that, I noticed PS5 doesn't have optical anymore so the TV would process it.

So here my idea already gets cracks on the surface since I forgot that PS5 doesn't have the output and the LG only outputs stereo PCM, maybe 2.1

Outputs:
8 channels balanced would be ideal for all future purposes, currently needed 4
FIR EQ for room correction, currently done with PC since there's enough power and almost no delay.

 

[mdsimon2]

Inputs:
PC over USB: Mostly stereo, sometimes 5.1 PCM for gaming (reduced to 4.0 by windows or my AVR since I only have 4.0)
Optical from TV: PCM stereo, pre-decoded stuff from Nvidia Shield (so also PCM), surround only supports lossy dd 5.1 it seems.
Optical from consoles: ditch that, I noticed PS5 doesn't have optical anymore so the TV would process it.

So here my idea already gets cracks on the surface since I forgot that PS5 doesn't have the output and the LG only outputs stereo PCM, maybe 2.1

Outputs:
8 channels balanced would be ideal for all future purposes, currently needed 4
FIR EQ for room correction, currently done with PC since there's enough power and almost no delay.

Thanks for the info.

I should warn that although I like DIY tinkering many of these issues are nicely solved by an AVR. I also have limited experience with multichannel formats but have played around with it some.

I would make a RPi4 running CamillaDSP the heart of the system. This gives the ability to switch inputs by changing configurations, extensive DSP capability and volume control.

For PC over USB you would use the RPi4 in USB gadget mode as a CamillaDSP capture device. For simplicity I would run this at single sample rate like 48 kHz. You can specify the number of channels you want to the gadget to appear as (in your case it sounds like you want 4 channels). I've tested this with 8 channels on both Mac and PC with a MOTU Ultralite Mk5 and it appears to work fine. I've been able to play Dolby TrueHD demos in VLC and the output works as expected. REW works fine and I can play to every channel although I needed to use ASIO4ALL to see all the channels on the PC.

For optical from TV you start to run in to clocking issues. For example you could use the TOSLINK input of the MOTU Ultralite Mk5 but you need to change the clock source to optical when you do this. There are other options like using a separate TOSLINK to USB card like such as https://hifimediy.com/product/hifime-ur23-spdif-optical-to-usb-converter or https://hifimediy.com/product/s2-digi/ however depending on your TV you might have issues when the signal stops. The miniDSP 2x4HD can also act as a TOSLINK to USB device and seems more robust in this regard. You could also do lossy DD 5.1 with a cheap decoder like the Dolby DP562 but would be better suited with a DAC like the Okto dac8 pro which has multiple stereo digital inputs, although this would require you to change the operating mode of the Okto from Pure USB to USB / AES.

For the PS5 I assume you could use a HDMI extractor to either get a PCM stereo or a DD 5.1 signal.

Honestly I would probably just wait for the miniDSP Flex HT as that would solve a lot of your issues. As it stands it is a lot of pain for little gain.

Michael

 

[Puoskari]

Hi I just skimmed throught the discussion and I was thinking that using RPi compute module as the brain would be quite clean solution. It would be easily replaceable and compact. Only issue is that it's not as prototyping friendly.

EDIT: here's my simplified framework. I find that at the moment there is no proper phono to digital conversion in any non-standalone systems. I think it could be an interesting and not too difficult to implement. We could then use RPi's dsp to do the RIAA correction.

 

[mr.anderson]

Is there a recap how far this project has progressed?

 

[voodooless]

Is there a recap how far this project has progressed?

Sure:

It went nowhere

 

[roog]

Sure:

It went nowhere

Yes it appears that this is a tough one!
Lots of requests for features and a few bright ideas and not enough doers, me included, oh the shame.

 

[Ralph_Cramden]

Sure:

It went nowhere

Well, it went around in circles for a while...

Many of us just bought WiiMs, and have no regrets.

 

[mdsimon2]

Hi I just skimmed throught the discussion and I was thinking that using RPi compute module as the brain would be quite clean solution. It would be easily replaceable and compact. Only issue is that it's not as prototyping friendly.

EDIT: here's my simplified framework. I find that at the moment there is no proper phono to digital conversion in any non-standalone systems. I think it could be an interesting and not too difficult to implement. We could then use RPi's dsp to do the RIAA correction.

View attachment 283647

Check out the link in my signature, it basically does what you suggest (RPi acting as DSP / streamer + display + remote control). Although the official ASR streamer never went anywhere it was a big motivation for me and I received a lot of help in this thread to develop the approach in my thread and there are several folks on ASR who have used my tutorial to implement similar setups. I've also used the CM4 successfully but it requires some tinkering with certain DACs, this was actually discussed in this thread (search this thread for CM4).

Michael

 

[jmf11]

I need multi channel and active amplification. I like Linux on SBC and CamillaDSP. There are plenty of good differential analog input ClassD modules and chips. To my eyes the multi-channel MOTU, Okto DAC8 look expensive. They have many bells and wisles I don't need.

DIY multichannel USB 2.0 UAC2 is not easy. However several SBC running Linux support TDM (unfortunatly not the RPi). There are many examples on the net of SBC/SOM running Linux and interfacing CODEC/DACs with TDM.

Could a reasonnably simple AK4458 board be designed to get TDM in => 8x differential analog out ?

Would this be usefull to a sufficient number of use cases / persons to justify the design effort ?

I'm really interested to have an idea of how many we are concerned / interested in this type of system: Linux on SBC / Camilla DSP ... multi-channel Class D amplifiers.

JMF

I have not yet sorted out if, if SBC+DAC+ amps are in the same box, then they need buffers in between. In TI designs (like https://www.ti.com/lit/pdf/tidud45), the amplifiers are connected just after the DAC (just few passive parts in between).

Sure that having the DAC board manage the master clock would be an asset, but more complex.

 

[Kal Rubinson]

I need multi channel and active amplification. I like Linux on SBC and CamillaDSP. There are plenty of good differential analog input ClassD modules and chips. To my eyes the multi-channel MOTU, Okto DAC8 look expensive. They have many bells and wisles I don't need.

Topping DM7?

 

[jmf11]

Correct, as alternatives, I have identified already:

Competitors:

• Behringer UMC1820: ~260€
• Evo by Audient EVO 16 interface audio : ~435€
• Topping DM7: ~599€
• MOTU - Interface audio USB UltraLite-mk5 18 x 22: ~730€
• Okto DAC8 : ~1300€

That's why I try to get a grasp about the need (market) for a cheaper, smaller, possibly more flexible (Open, access to configuration of the chip) option, possible to integrate in a Stramer/DAC/amplifiers box.

JMF

 

[JoetheLion]

Hi all,

maybe the wrong forum, but here is a DIY streamer that immediately makes you think of the beautiful devices from Rose and NAD. Based on a Raspberry Pi 4B and a Khadas Tone 1 board in a used Pioneer case. Admittedly with a lot of time for building (about 50 hours), but the result is really worth seeing (and probably also worth hearing)!

Here is the tutorial (in german and unfortunately behind a paywall):

Schicker Streamer

Raspberry Pi, guter Klang und schickes Design passen nicht zusammen? Doch, dieses Projekt beweist es. Mit edler Elektronik, einem Anlagen-kompatiblen Gehäuse und Breitwand-Infoscreen passt dieser Netzwerkplayer auch in Ihr Wohnzimmer-Orchester.

www.heise.de

 

[SmartCross]

In case anyone is interested, this is my project inspired by ASR streamer, and matches some of its aspects:

Introduction to the SmartCross project

Many of us are fascinated by the idea that we can process audio signals precisely and flexibly in the digital domain. Currently, there are numerous options available in the market, including popular offerings like MiniDSP and FusionAMP, each with their unique aspects. People have also brewed...

www.audiosciencereview.com

 

[Deleted member 65547]

I think it's a great idea.
For my part, I suggest valid support for lossless radios.
There are excellent lossless radios, even a 24/192 dedicated to vinyl (Mother Earth) but the support for this type of service always leaves a lot to be desired.
For example, it would be interesting to have the possibility of recording their programming directly in digital format.
Another idea could be to maintain a centralized complete of the main characteristics of each, kept constantly updated by someone who follows this particular streaming source.

 

[voodooless]

There are excellent lossless radios, even a 24/192 dedicated to vinyl (Mother Earth) but the support for this type of service always leaves a lot to be desired.
For example, it would be interesting to have the possibility of recording their programming directly in digital format.

That's trivial from Mother Earth, just save the web stream:

wget https://motherearth.streamserver24.com/listen/motherearth/motherearth

 

[Deleted member 65547]

That's trivial from Mother Earth, just save the web stream:

wget https://motherearth.streamserver24.com/listen/motherearth/motherearth

I expressed an opinion that called for a solution that was a little more complete than a single radio.
They all have a website, but browsing websites is not the most comfortable.
I currently manage lossless radios with the WiiM Pro general stream plugin (and the USB Audio Player Pro application), but it could be done much better than a simple aggregator.

 

[somebodyelse]

Managing a list is a project in itself, and better handled separately so it could be used by multiple streamers. I suspect there is more than one like this already - I haven't checked where the LMS plugins get their list(s) from.

Adding an easy record function could get sticky from a copyright perspective, varying depending on what part of the world you are in.

 

[Ritz]

I have been using this combo:

Wiim Pro Plus Streamer ---coax---> SMSL DO100 ---> Denon AVR

Amazon.com

Amazon.com

The Wiim device has a simple android application that I run on a tablet to stream lossless music from Amazon Music HD to my system. I like it a lot better than the previous solution....using Denon's HEOS application to stream lossless content from the same source using an app on my phone. The Wiim application is a lot easier to use and the addition of an external DAC rather than using my Denon AVR to decode has significantly improved the perceived quality of the output. I'm a tech person with a lot of experience hacking on RPi's, but I don't think I could some up with something this easy to use at a lower price point. And this system is user friendly enough that my wife and kids can use it without involving me. The weakest link for me is probably the older Denon AVR that feeds my external amp.

Best,

 

[Ralph_Cramden]

Some interesting modules and APIs here:

https://www.streamunlimited.com/hardware-modules/

 

[voodooless]

Some interesting modules and APIs here:

https://www.streamunlimited.com/hardware-modules/

I doubt these things are available for us mere mortals to buy this and the software licenses for DIY projects. Would be cool if that were the case though!