ASR Open Source Streamer Project

[somebodyelse]

According to Khadas the VIM3L can run android and roon and ubuntu and possibly sync to multiple tone boards for multichannel dac out https://www.khadas.com/product-page/vim3l-htpc-kit
Search (link does not work)
https://forum.khadas.com/t/sync-multiple-tone-boards/7412

Well...the VIM can do up to 8 channels via I2S/TDM, but the Tone Board (TONE1) doesn't expose its I2S in a way that it can be used without either hardware modification or custom firmware - see #214 for details. I assume this is what @Gouwa wanted to ask the team about, and why hyphop responded suggesting an alsa virtual multichannel configuration (with potential clock drift problems we might want to measure) or a proper multichannel interface like the MOTU 8A. You could use the VIM with other TDM capable DAC boards/hats, but we would have to identify some with good performance. There are other SBCs with TDM capability, like the BeagleBone Black, although that may be a poor example given its limited CPU.

 

[BDE]

Some thoughts from a user perspective, the basis could be a Nvidia Shield TV PRO and add:
# a good USB DAC/ audio interface (2 channel or multichannel) -> already hard to get it work? As far as I know some already using external USB DAC`s on the Shield
# a DSP function including channel routing -> I guess this is the hard part, something like EqualizerAPO for the Nvidia. With the Linux and Android combination of the Shield there should be some options?

This would cover already a lot of user cases:
# simple stereo setup with room correction
# DIY multiway active stereo setup (crossover, EQ, delay, gain, room corrction)
# multichannel home cinema

However I don`t know how tough it would be to get such a combination to work.

 

[Chrise36]

Well...the VIM can do up to 8 channels via I2S/TDM, but the Tone Board (TONE1) doesn't expose its I2S in a way that it can be used without either hardware modification or custom firmware - see #214 for details. I assume this is what @Gouwa wanted to ask the team about, and why hyphop responded suggesting an alsa virtual multichannel configuration (with potential clock drift problems we might want to measure) or a proper multichannel interface like the MOTU 8A. You could use the VIM with other TDM capable DAC boards/hats, but we would have to identify some with good performance. There are other SBCs with TDM capability, like the BeagleBone Black, although that may be a poor example given its limited CPU.

What about the extension card does not it expose i2s and what about spdif they say it is synced when by spdif

 

[Chrise36]

https://ismosys.com/audio-chips/ess...annel-dac-with-2vrms-line-drivers-eval-board/
We can send something like this to Amir to have it measured if it is compatible

 

[voodooless]

It would be a nice chip for a simple multichannel solution, however that board, like most eval boards, is far to expensive for what you get.

But what is the general plan now? @StefaanE, is there a plan to get this project out of the mud? There are lots of very cool and interesting ideas here! But that is also the biggest problem. There are just to many options and opinions.

 

[Chrise36]

I say lets start a donation for the khadas and the dac or dacs if someone feels he can start something with these.

 

[mdsimon2]

https://ismosys.com/audio-chips/ess...annel-dac-with-2vrms-line-drivers-eval-board/
We can send something like this to Amir to have it measured if it is compatible

Interesting. I had seen the 9080Q on the ESS website recently and had wondered about the cost. The fact that the evaluation board is so much less than the 9026/9028/9038 pro 8 channel evaluation boards bodes well for a decently priced 8 channel commercial offering (although the spec’d performance is not as good as those chips).

It says that it is currently back ordered (checked Mouser and Shaw but did not see it there). It also looks like you may need to establish a business account to order from Ismosys. If it pops up at Mouser/Shaw for a similar price I will buy one as a learning exercise.

Michael

 

[Kegemusha]

(I have no folow this so, sorry, not sure what you want to do, I guess there is a minimun requirementfor start?

There are already good HW to build on from there, is not a Rpi having all this and can be use already (DAC, AMP, GPIOs, WiFi, a lot of open source SW and etc)? you just need the room correction part before the signal goes out.
Many FPGAs/DSP have DACs, if you take in the info from the room, by a MIC (where you know the profile) you can tweak the DAC before signal goes out.

 

[notabenem]

Interesting. I had seen the 9080Q on the ESS website recently and had wondered about the cost. The fact that the evaluation board is so much less than the 9026/9028/9038 pro 8 channel evaluation boards bodes well for a decently priced 8 channel commercial offering (although the spec’d performance is not as good as those chips).

It says that it is currently back ordered (checked Mouser and Shaw but did not see it there). It also looks like you may need to establish a business account to order from Ismosys. If it pops up at Mouser/Shaw for a similar price I will buy one as a learning exercise.

Michael

I strongly think we should not get lost in the DAC part, as it is mostly only a question of money and it should be viewed only as an add-on (rather than a core part), as i tried to outline here https://www.audiosciencereview.com/...pen-source-streamer-project.20840/post-738583

 

[somebodyelse]

What about the extension card does not it expose i2s and what about spdif they say it is synced when by spdif

As I said in #214 the DAC's I2S is exposed on the 30 pin FPC '8 Channels Ext' but it's connected to the XMOS as well, so you need either hardware mods or custom firmware to use it. If you're using SPDIF it's the same as any other SPDIF DAC - so long as you're using multiple SPDIF outputs clocked from the same source.

 

[mdsimon2]

I strongly think we should not get lost in the DAC part, as it is mostly only a question of money and it should be viewed only as an add-on (rather than a core part), as i tried to outline here https://www.audiosciencereview.com/...pen-source-streamer-project.20840/post-738583

Sorry, my comment was more for general learning/interest and not directly related to project. I am always interested in cheap, high performance multi-channel DACs.

Michael

 

[gingerbeer]

I strongly think we should not get lost in the DAC part, as it is mostly only a question of money and it should be viewed only as an add-on (rather than a core part), as i tried to outline here https://www.audiosciencereview.com/...pen-source-streamer-project.20840/post-738583

I see it a bit differently. The mini computer (rpi, etc) with software (moode, which includes Camilladsp) and a 2 channel output (USB or hat dac) is solved technically and I think we are at the point of discussing aesthetics.
- multiple boxes hooked to a computing device that runs Moode (pc/Nuc/rpi or similar/ mac, etc).
- minidsp shd series for one box with a recommended review here on ASR
- audiophonics has this cool one box diy kit with rpi, volume and dual screens (recommended by Amir)
https://www.audiophonics.fr/en/netw...8q2m-streamer-for-raspberry-pi-4-p-14639.html

so to me two channel is playing in a very well covered space.

The multi channel dsp offering is where there is a gap in the market and I see massive potential to genuinely create something that will open a new wave of possibilities for people. But precisely because there is a gap in the market it’s hard to identify the missing pieces. That ES9080 board looks like it could indeed be the missing piece of the puzzle

 

[Phorize]

I see it a bit differently. The mini computer (rpi, etc) with software (moode, which includes Camilladsp) and a 2 channel output (USB or hat dac) is solved technically and I think we are at the point of discussing aesthetics.
- multiple boxes hooked to a computing device that runs Moode (pc/Nuc/rpi or similar/ mac, etc).
- minidsp shd series for one box with a recommended review here on ASR
- audiophonics has this cool one box diy kit with rpi, volume and dual screens (recommended by Amir)
https://www.audiophonics.fr/en/netw...8q2m-streamer-for-raspberry-pi-4-p-14639.html

I generally agree that the pieces are available for 2 channel but I haven’t seen those pieces brought together on one project. The audio phonics thing seems a step in the right direction but appears to rely on an audiophonics build of volumio to work fully. I’m not sure about the heat dissipation on the pi 4 either.

 

[gingerbeer]

I generally agree that the pieces are available for 2 channel but I haven’t seen those pieces brought together on one project. The audio phonics thing seems a step in the right direction but appears to rely on an audiophonics build of volumio to work fully. I’m not sure about the heat dissipation on the pi 4 either.

Pi4 doesn’t need cooling for audio - I have one without any heat sink at all that does audio and runs a 4k photo slideshow simultaneously and it’s fine.

 

[notabenem]

...
so to me two channel is playing in a very well covered space.

The multi channel dsp offering is where there is a gap in the market and I see massive potential to genuinely create something that will open a new wave of possibilities for people. But precisely because there is a gap in the market it’s hard to identify the missing pieces. That ES9080 board looks like it could indeed be the missing piece of the puzzle

Well explained, thanks. This was the needed fact I was missing. So we're now discussing product positioning and differentiation, that should, obviously, precede product design. Very well.

 

[Skeptischism]

I think that statement needs qualifying. you can certainly push a pi4 with audio-related tasks. plain vanilla playback, with no FIR, room correction etc, not so much.

 

[voodooless]

So we're now discussing product positioning and differentiation, that should, obviously, precede product design.

What have we been doing the last 13 pages then?

 

[Skeptischism]

although TDM has a crapload of promise, from a hardware perspective, it's not exactly widely accessible.

 

[Skeptischism]

If you could establish a minimum requirement, confirm that it does not require onboard DSP (use camilla on rpi, or other client, rather than DSP hardware) I may be able to design a PCB to suit the project. I would suggest ES9028 or one opf the other multichannel ESS offerings, rather than 9038PRO. 9038PRO is a fabulous chip, but places a lot of demands on the rest of your design and paints you into a corner with its huge current output.

 

[Skeptischism]

But i'm not up for design by committee,. Who should I talk to about this?

on the 9080, yes, I spotted that a while ago too and its interesting. the eval board is ridiculously priced, considering the chip doesnt need an IV stage, has internal line drivers and has no need for a complex or high performing power supply, due to decent, but not OTT performance. ESS are not exactly known for dealing with smaller projects or DIYERs, so I would avoid basing the board on anything that isnt part of the portfolio on sale at mouser.