ASR Open Source Streamer Project

[StefaanE]

If the DAC is supposed to be external (not a big fan myself) it is also total overkill unless one wants Dirac specifically, perhaps.

Last thing I was wondering are there any somewhat affordable well measuring pci-e multichannel soundcards with Linux drivers? That might be the cheapest and most straightforward way to get internal DACs for those who desire such.

DACs are supposed to be external, from #4 in Amir's requirements list.

 

[Thomas savage]

Hey you all. I was wondering if I can get the community to help define, implement and grow an open-source, budget streamer. There are commercial solutions out there but I think we can do better than those.

Here are some aspects I am thinking of:

1. Built on a low cost, readily available hardware platform like RPi. Ethernet and Wifi support of course.

2. End-point support for Roon and Airplay. You call can suggest others.

3. Ability to download parametric EQ or FIR filters for speaker and room EQ. Integration with other tools should be provided for automatic Room EQ.

4. Support for active speakers using software crossovers and multiple external DACs. Support for sub-woofer outputs using independent DAC or whatever is in RPi if it is any good. If not, some kind of low cost HAT DAC.

5. GUI in a web-browser for configuration of above.

6. Support of optional display for cool animations/VU meters. I like explore very low latency implementation of this to keep better sync with music.

7. Cloud/automatic firmware update service with proper security fixes and implementation.

8. Availability of a complete solution in a case ready to go (sans DACs of course).

9. No need for internal UI to browse music and such. All of that will be driven by the client app elsewhere. Indeed the device should run headless out of the box. Per #5, web UI should be there for configuration.

I like us to organize this properly with a project leader and master decision maker in accepting changes, revisions, proper testing process and of course developers to work on these bits. I have one capable member (@StefaanE) volunteering to lead the project and some other bits but may need more development resources. I can be the marketing/product planning person.

This will be an adjunct to project @Rick Sykora is running on open-source ASR speaker design. I look to him to be the high level keeper of all of these sub-projects but need a "butt on the line" for this subsystem.

I don't have a name for this project so feel free to suggest some.

Some parts of the above are easy to do but the rest may present some challenges. Let's put all of our energy and resources toward it as I think we badly need such a simple, reliable, yet highly functional product. I know I need one as I am tired of maintaining my Windows PC based server for this use.

To get things started, let's have a discussion on above feature list and define it. Plus see who all can volunteer to help with what part of it.

Thank you all.

Brilliant idea , thanks in advance to all members who end up making this a reality.

How exciting!

 

[StefaanE]

Agreed. I was only comparing miniDSP v Audiophonics.

What is the target cost of the ASR streamer?

Well, Amir's #1 requirement mentions "low cost", but like beauty, cost is in the eye of the beholder (or more accurately, their wallet/pocketbook ).

 

[buz]

DACs are supposed to be external, from #4 in Amir's requirements list.

It says multiple external DACs first - how likely is it that we get multiple DACs in sync?

It also mentions pi hats at which point I am no longer sure what is really intended...

 

[mdsimon2]

I'm still not entirely clear on how much is included in the package. If I'm reading one of the comments correctly they can't swap the DACs for coax/toslink digital outputs as they don't have a method of controlling the volume on the MiniSharc, which seems a little odd. I'm not sure how the MiniSharc gets programmed either - AFAIK the MiniDSP software won't run on linux, let alone a Pi, so I guess you plug it into a Windows machine somehow? It's one of the things that's led me to avoid MiniDSP boards so far, so if there's now a way to program them from the Pi I'll be all ears.

I considered purchasing one of these a while back. As a one box active speaker solution with multiple inputs, good processing power, volume indication and decent DACs I am not sure it can be beat for the price. That being said I am not sure how many people on this forum implement DIY active speakers and that requirement feels a bit like overkill.

The volume control for this unit is done using a microcontroller for the DAC(s) volume control and does NOT use the miniSHARC volume control. This is good because the DACs always receive a full amplitude signal but you need to be careful with programming boosts in the miniSHARC as they may cause digital clipping unless they are appropriately attenuated.

The miniSHARC requires a Windows / Mac computer to program. There is a mini USB port on the back of the enclosure labeled "DSP" to facilitate this.

The specs say 1.54 vrms output voltage on the DACs but Audiophonics told me they can increase this to 2 vrms. They also said they can add a 4th DAC for just the price of a DAC.

Michael

 

[somebodyelse]

It says multiple external DACs first - how likely is it that we get multiple DACs in sync?

It also mentions pi hats at which point I am no longer sure what is really intended...

If you have multiple digital outputs sharing the same clock then the external dacs will stay in sync. That's the case for DSP systems like the MiniSharc, the HifiBerry DAC + DSP and so on, and the XMOS USB multichannel adapters among others. And the TDM output on the Beaglebone. You need to design with it in mind, but it's not unrealistic.

 

[abdo123]

Nice find. Looks quite decent, but it's not really very cheap. A pi and an Okto 8 would cost about the same, would have better performance and a nicer case (if you hide the pi somewhere). Software DSP would take care of the rest.

It's really strange how people assume that there is a 8-channel DSP engine already coded and compiled for the raspberry pi.

That product ticks all the boxes without a doubt. except maybe an ADC for Vinyl playback.

 

[abdo123]

What advantage does this unit have over the miniDSP SHD?

As McFly said in his post:

"The ultimate would be a MiniDSP SHD/SHD studio without the poor Volumio integration (insert ASR's NEW improved software)"

it has two extra channels, but no DIRAC and no ADC. so yeah i would go for the MiniDSP SHD at that price range.

 

[abdo123]

Personally I would not extend the range of this project beyond PEQ and FIR filters for two stereo inputs.

make a different project for a full fledged crossover engine or perhaps come up with a way to improve the DAC implementation of the lower tier MiniDSP products.

 

[TimW]

That being said I am not sure how many people on this forum implement DIY active speakers and that requirement feels a bit like overkill.

This ASR streamer project is considered to be a companion to the ASR speaker project (Directiva). So the crossover capabilities are a very important, if not the most important aspect of this project.

Personally I would not extend the range of this project beyond PEQ and FIR filters for two stereo inputs.

make a different project for a full fledged crossover engine or perhaps come up with a way to improve the DAC implementation of the lower tier MiniDSP products.

There are plenty of streamers out there and only a few options for doing active crossovers. I think the biggest thing this project could offer is a combination of those things that is easy to use and works like an appliance. No complex OS to boot up and run programs in, just a low power box that is always on and configurable via a web UI.

 

[abdo123]

There are plenty of streamers out there and only a few options for doing active crossovers. I think the biggest thing this project could offer is a combination of those things that is easy to use and works like an appliance. No complex OS to boot up and run programs in, just a low power box that is always on and configurable via a web UI.

I've been using MiniDSP 2*4 HD for quite sometime now, and the software implementation is SOLID. it is running all the time and changing the inputs is so seamless you could do an ABX test with it. It's just a really good product on the software side of things. it's incredible how much it does for 200$.

I have it plugged via USB to the raspberry pi and i pretty much have all the boxes ticked in the project goals (for 300$).

Now if someone can come up with a way to lower the noise floor (it has 90 dB SINAD) or increase linearity (it is also on 90 dB) that combination would be a beast.

 

[somebodyelse]

It's really strange how people assume that there is a 8-channel DSP engine already coded and compiled for the raspberry pi.

We know they compile, and most can be installed via apt in raspbian. The only assumption is that they'll work the same on the Pi as they do on a desktop linux - indeed I wouldn't rule out someone here having used one or more of them already.

 

[StefaanE]

As a one box active speaker solution with multiple inputs, good processing power, volume indication and decent DACs I am not sure it can be beat for the price. That being said I am not sure how many people on this forum implement DIY active speakers and that requirement feels a bit like overkill.

I get the feeling the solution will have to be extremely modular to meet all requirements.

Suggestion: can we somehow split the project into a hardware and a software track? Obviously, the hardware will influence what software can be used (e.g. the Daphile doesn't support ARM processors), and vice-versa, but I after all the suggestions I would like to converge on a consensus on the basic platforms.
We might need more than two tracks, given the diversity of the requirements at the software level -- the actual streamer that needs to connect to the outside world to get the data, the classification and selection of the tracks, the digital signal processing etc.

@amirm, do we have a facility to store a common spreadsheet-like document where we could structure the information?

 

[abdo123]

We know they compile, and most can be installed via apt in raspbian. The only assumption is that they'll work the same on the Pi as they do on a desktop linux - indeed I wouldn't rule out someone here having used one or more of them already.

yes but to implement on the fly real-time changes to the processing and a GUI would be incredibly tedious.

This would be necessary since the Pi has to control the main volume.

 

[StefaanE]

Re ARC, I plugged a Nubert ARC dongle in a USB port on my Mac, and it remained gloriously unrecognised.

 

[TimW]

If you have multiple digital outputs sharing the same clock then the external dacs will stay in sync. That's the case for DSP systems like the MiniSharc, the HifiBerry DAC + DSP and so on, and the XMOS USB multichannel adapters among others. And the TDM output on the Beaglebone. You need to design with it in mind, but it's not unrealistic.

I think this project is best kept in the software realm. It will need to be compatible with multi-channel DACs for the crossover and I think that is best done over USB. There are HDMI options as mentioned earlier in this thread but I'm not sure how those perform. We know the Okto dac8 performs very well along with some recording interfaces with multiple outputs and these can be connected via USB. Then there are sound cards like the EVGA NU Audio Pro that perform very well but are designed for a PC case. They might work with some sort of adapter. I would like to see this streamer be a platform that is compatible with multichannel DACs for active crossovers along with stereo DACs for people with simpler setups. That keeps it modular without requiring hardware development.

 

[TimW]

I've been using MiniDSP 2*4 HD for quite sometime now, and the software implementation is SOLID. it is running all the time and changing the inputs is so seamless you could do an ABX test with it. It's just a really good product on the software side of things. it's incredible how much it does for 200$.

I have it plugged via USB to the raspberry pi and i pretty much have all the boxes ticked in the project goals (for 300$).

Now if someone can come up with a way to lower the noise floor (it has 90 dB SINAD) or increase linearity (it is also on 90 dB) that combination would be a beast.

I own a miniDSP 2x4 kit, 2x4 in box, DDRC-24, SHD, and an OpenDRC-DI that used to be a DA8 and is modified with a WaveFlex controller. I'm pretty well versed in the operation of miniDSP products. The SHD has much better performance than the 2x4HD and satisfies me completely but it is not cheap and only has 4 outputs. The built in Volumio streamer sucks IMHO and the included DIRAC room correction, while nice, is a major contributor to the cost.

I would like to see this streamer project produce an image for RPI. You set it up like any RPI streamer, connect a high performance DAC, configure via the web UI, and you're off to the races. Of course this is how most RPI based streamers work like the one I use, RopieeeXL. The differentiating factor should be that in the UI of the ASR streamer, you will be able to configure crossovers and equalization, maybe even use a plugin for automated EQ. For instance check out this demonstration of REW Auto EQ. That is using the free software (REW and Sigma-Studio) to automate room correction to some extent, which is a big help to newcomers. With this type of setup you are not tied to to any costly software or specific hardware, for instance you would be able to use a DAC with better performance than the 2x4HD.

 

[abdo123]

I own a miniDSP 2x4 kit, 2x4 in box, DDRC-24, SHD, and an OpenDRC-DI that used to be a DA8 and is modified with a WaveFlex controller. I'm pretty well versed in the operation of miniDSP products. The SHD has much better performance than the 2x4HD and satisfies me completely but it is not cheap and only has 4 outputs. The built in Volumio streamer sucks IMHO and the included DIRAC room correction, while nice, is a major contributor to the cost.

I would like to see this streamer project produce an image for RPI. You set it up like any RPI streamer, connect a high performance DAC, configure via the web UI, and you're off to the races. Of course this is how most RPI based streamers work like the one I use, RopieeeXL. The differentiating factor should be that in the UI of the ASR streamer, you will be able to configure crossovers and equalization, maybe even use a plugin for automated EQ. For instance check out this demonstration of REW Auto EQ. That is using the free software (REW and Sigma-Studio) to automate room correction to some extent, which is a big help to newcomers. With this type of setup you are not tied to to any costly software or specific hardware, for instance you would be able to use a DAC with better performance than the 2x4HD.

It's just that I think Streamers should not be responsible for Active crossover.

Almost everyone in this forum has either a CD collection or a Vinyl collection or has some other input (like a TV) other than local files and streaming platforms.

That's why i think this streamer should not include that, and for people who do want to have that function and keep it limited to streaming they have Roon.

 

[TimW]

It's just that I think Streamers should not be responsible for Active crossover.

Almost everyone in this forum has either a CD collection or a Vinyl collection or has some other input (like a TV) other than local files and streaming platforms.

That's why i think this streamer should not include that, and for people who do want to have that function and keep it limited to streaming they have Roon.

I understand that sentiment, it is why I own the SHD. I also have Roon but I want room correction for all of my sources. From what I understand it is also possible to do this using a HTPC with an appropriate sound card or interface that provides inputs. Ideally this would be an option with this streamer as well.

But regardless of where in the chain we think things should be done, here are three of the features Amir specifically requested for this project:

3. Ability to download parametric EQ or FIR filters for speaker and room EQ. Integration with other tools should be provided for automatic Room EQ.

4. Support for active speakers using software crossovers and multiple external DACs. Support for sub-woofer outputs using independent DAC or whatever is in RPi if it is any good. If not, some kind of low cost HAT DAC.

5. GUI in a web-browser for configuration of above.

 

[voodooless]

It's really strange how people assume that there is a 8-channel DSP engine already coded and compiled for the raspberry pi..

Who is assuming what here?

But the fact is: it is coded and compiled.. Moode has the capabilities to do this already using CamillaDSP.