Budget Standalone "Toslink > DSP > Toslink" with Camilladsp. Set up instructions for newbies.

[Rednaxela]

Yep, the question is always how it behaves under linux and what it is capable of. I would invest some time trying to find out some info in the internet or buying from a shop that you can return it easily if it doesn't work.

Good points, thanks. Some promising signs:

Matrix:Vendor-ESI - AlsaProject

www.alsa-project.org

USB sound card review: ESI U24 XL

Website of Nathalie Beimler. Review of the ESI U24 XL USB sound card with focus on measured audio performance and electronics design.

nathaliebeimler.com

But yeah the proof of the pudding etc. etc…

 

[mdsimon2]

I can think of few ways to get multiple digital inputs.

1) Use an external switcher.

This is nice because you do not need to reload CamillaDSP assuming that source sample rate is identical. On one of my systems I use a miniDSP OpenDRC-DI for this which is overkill but I already had it and it has an ASRC so you do not need to worry about source sample rate.

2) Use a single device with multiple digital inputs.

Pro audio interfaces often have multiple digital audio inputs as well as more flexible clocking options but are more expensive. Depending on clocking and sample rate you may not need to reload CamillaDSP configurations. The easiest interfaces to deal with will be ones that have an ASRC.

3) Multiple devices.

You may have issues with identically named devices, for example miniDSP has implemented different firmware for their USBStreamer / MCHStreamer so you can name devices differently. You will definitely need to reload CamillaDSP configurations with multiple devices.

Michael

 

[MCH]

I can think of few ways to get multiple digital inputs.

1) Use an external switcher.

This is nice because you do not need to reload CamillaDSP assuming that source sample rate is identical. On one of my systems I use a miniDSP OpenDRC-DI for this which is overkill but I already had it and it has an ASRC so you do not need to worry about source sample rate.

2) Use a single device with multiple digital inputs.

Pro audio interfaces often have multiple digital audio inputs as well as more flexible clocking options but are more expensive. Depending on clocking and sample rate you may not need to reload CamillaDSP configurations. The easiest interfaces to deal with will be ones that have an ASRC.

3) Multiple devices.

You may have issues with identically named devices, for example miniDSP has implemented different firmware for their USBStreamer / MCHStreamer so you can name devices differently. You will definitely need to reload CamillaDSP configurations with multiple devices.

Michael

Yes, that is the beauty of spdif. If the sample rate is the sam you can just buy one of these cheap switchers. Some even come with a remote control. And for the output, even easier, i have one of these toslink splitters that costed nothing and works perfectly.
The good thing would be it it was effectively a multichannel device, but i bet it is not.

 

[MCH]

Btw, just discovered yesterday that if you set the cheapo card in post #1 as 8 channel dac in camilladsp, the toslink outputs channels 0 and 1 simultaneously to the 8 analog channels. Trying to find out now if the dealy is good enough to use the toslink for the mains with a better dac and one of the 6 others for a sub. If it works, i will be very happy as it allows me to keep on using my beloved 2 channel dac.
If someone knows other cheap but decent multichannel cards that do the same, please let me know.

 

[mdsimon2]

Btw, just discovered yesterday that if you set the cheapo card in post #1 as 8 channel dac in camilladsp, the toslink outputs channels 0 and 1 simultaneously to the 8 analog channels. Trying to find out now if the dealy is good enough to use the toslink for the mains with a better dac and one of the 6 others for a sub. If it works, i will be very happy as it allows me to keep on using my beloved 2 channel dac.
If someone knows other cheap but decent multichannel cards that do the same, please let me know.

Hmm, that is too bad.

Does that mean that you cannot apply processing between the SPDIF input and the analog outputs because there is already routing occurring outside of CamillaDSP?

Michael

 

[MCH]

Hmm, that is too bad.

Does that mean that you cannot apply processing between the SPDIF input and the analog outputs because there is already routing occurring outside of CamillaDSP?

Michael

No, the opposite, camilladsp processing is effective and the toslink outputs channels 0 and 1 processed. Channels 0 to 7 go out also processed through the analog outputs.
So channels 0 and 1 processed are actually dupplicated (toslink + analog).
I like the fact that this allows to use my D30pro for the mains and feed the sub from the cheapo card analog after xover in camilla (if latency allows...tbd)

 

[mdsimon2]

No, the opposite, camilladsp processing is effective and the toslink outputs channels 0 and 1 processed. Channels 0 to 7 go out also processed through the analog outputs.
So channels 0 and 1 processed are actually dupplicated (toslink + analog).
I like the fact that this allows to use my D30pro for the mains and feed the sub from the cheapo card analog after xover in camilla (if latency allows...tbd)

Ah, got it, only channels 0/1 are duplicated, everything else works as you expect. I guess that makes sense from your cat /proc/asound/xxx/stream0 output as it only shows 8 output channels, not 10.

I agree that this should still work fine. TOSLINK will ensure that your D30pro stays sync'd to the multichannel DAC. You can adjust latency as needed in CamillaDSP (would be helpful to have an ADC to measure latency difference between the two). The only limitation is that you need to use channels 3-7 for the sub which is not a huge deal.

Honestly a pretty cool setup if you have a SPDIF source and want to integrate a sub. For less than $100 you can add DSP and a subwoofer output to an existing stereo DAC!

Michael

 

[MCH]

Ah, got it, only channels 0/1 are duplicated, everything else works as you expect. I guess that makes sense from your cat /proc/asound/xxx/stream0 output as it only shows 8 output channels, not 10.

I agree that this should still work fine. TOSLINK will ensure that your D30pro stays sync'd to the multichannel DAC. You can adjust latency as needed in CamillaDSP (would be helpful to have an ADC to measure latency difference between the two). The only limitation is that you need to use channels 3-7 for the sub which is not a huge deal.

Honestly a pretty cool setup if you have a SPDIF source and want to integrate a sub. For less than $100 you can add DSP and a subwoofer output to an existing stereo DAC!

Michael

Yup, i am pretty excited about it. Will report back how it works.
Only limitation for me is not being able to use the volume control of the d30pro anymore, that's why i was asking you yesterday about the flirk remote

 

[MCH]

(would be helpful to have an ADC to measure latency difference between the two).

Michael, I do have an ACD and REW. Can you point me, if you know one, in the direction of some instructions on how to measure the delay? Google shows me only documents aimed to professionals...

 

[mdsimon2]

Michael, I do have an ACD and REW. Can you point me, if you know one, in the direction of some instructions on how to measure the delay? Google shows me only documents aimed to professionals...

I outlined how to do it in this post -> https://www.audiosciencereview.com/.../okto-dac8-pro-alternative.25486/post-1006531.

Michael

 

[MCH]

I outlined how to do it in this post -> https://www.audiosciencereview.com/.../okto-dac8-pro-alternative.25486/post-1006531.

Michael

That is awesome.
Just one question. My ADC and the sub are unbalanced, the D30pro has both unbalanced and balanced line outputs.
I use the balanced outs of the d30pro to my Amp, but to do the delay measurements I will have to use the unbalanced.... Does it matter?

 

[mdsimon2]

That is awesome.
Just one question. My ADC and the sub are unbalanced, the D30pro has both unbalanced and balanced line outputs.
I use the balanced outs of the d30pro to my Amp, but to do the delay measurements I will have to use the unbalanced.... Does it matter?

I don't think there will be any difference in delay between balanced and unbalanced. If you wanted to confirm you could use a XLR to RCA adapter for the delay measurements.

Michael

 

[Rednaxela]

I can think of few ways to get multiple digital inputs.

Thank you for listing these. Very much appreciated!

My use case would be EQ/DRC on both TV and CD player digital output. So I guess that requires support for more than one sample rate. I understand how ASRC inside the sound card would take care of this and simplify things on the CDSP side.

However I understand that CDSP can do ASRC as well. Would this then require the configurations reloading you mentioned?

EDIT: Never mind I think I just distilled the answer from one of your earlier posts elsewhere. Sorry for the confusion.

 

[mdsimon2]

Thank you for listing these. Very much appreciated!

My use case would be EQ/DRC on both TV and CD player digital output. So I guess that requires support for more than one sample rate. I understand how ASRC inside the sound card would take care of this and simplify things on the CDSP side.

However I understand that CDSP can do ASRC as well. Would this then require the configurations reloading you mentioned?

EDIT: Never mind I think I just distilled the answer from one of your earlier posts elsewhere. Sorry for the confusion.

I'm not sure I addressed this concern specifically.

At least as of a year ago the ASRC implemented in CamillaDSP cannot handle large sample rate changes -> https://www.diyaudio.com/community/...overs-room-correction-etc.349818/post-6535507. As a result you need to reload the configuration to change the capture rate even if you are using the CamillaDSP ASRC.

This is an area I've been meaning to explore more as CamillaDSP does have the ability to measure sample rate. I think it should be possible to restart CamillaDSP with a new configuration based on this measured sample rate but I have not tried.

Michael

 

[dehati_paul]

Hi MarcosCH - This is super helpful and exactly what I have been looking for, where the output and internal processing bitrate and sampling frequency matches that of the inputs (miniDSP upsamples everything).

Three questions before I take the plunge:

1. Have you found out a simultaneous digital coax (not optical toslink) input/output solution that works with RPi4?

2. If not, then how did you make the SB X-Fi HD USB work with RPi4, as you mentioned earlier that you had to do some additional work?

3. Have you looked into or can you suggest how to make something like raptorlightning-i2s HAT work?


Thanks in advance!

dehati

 

[MCH]

Hi MarcosCH - This is super helpful and exactly what I have been looking for, where the output and internal processing bitrate and sampling frequency matches that of the inputs (miniDSP upsamples everything).

Three questions before I take the plunge:

1. Have you found out a simultaneous digital coax (not optical toslink) input/output solution that works with RPi4?

2. If not, then how did you make the SB X-Fi HD USB work with RPi4, as you mentioned earlier that you had to do some additional work?

3. Have you looked into or can you suggest how to make something like raptorlightning-i2s HAT work?


Thanks in advance!

dehati

Hi dehati,
Glad that it is helpful for you. To your questions:

1. No, I haven't searched nor I know of any USB card with coax in and out. My need was to use this with my tv as a source and my tv has toslink output. But if needed and you can't find any, you can always use two USB cards, one to capture and a different card, or a USB dac, to output.

2. The sb x-fi HD has toslink in and out. It is a great card that I still use as ADC to stream the signal from my turntable, but I remember to set it up properly was not that easy for me. Think that at that time those were my first attempts with camilladsp, maybe it is not that difficult after all. Unfortunately I didn't take notes, but I can tell you it is indeed possible

3. I don't know that specific hat. I never tried i2s hats because I consider they are relative expensive and of limited use compared with some very cheap and competent USB cards that you can also use outside the rasp pi world. I suggest you to ask in the camilladsp tutorial in this same forum.

4. Extra info: Eventually I used a pi 4b 2gb instead of the zero 2w and I find the set up much more stable. I used to leave it on literally for weeks with no need to reboot ever.

Hope it helps, good luck!

 

[dehati_paul]

Hi dehati,
Glad that it is helpful for you. To your questions:

1. No, I haven't searched nor I know of any USB card with coax in and out. My need was to use this with my tv as a source and my tv has toslink output. But if needed and you can't find any, you can always use two USB cards, one to capture and a different card, or a USB dac, to output.

2. The sb x-fi HD has toslink in and out. It is a great card that I still use as ADC to stream the signal from my turntable, but I remember to set it up properly was not that easy for me. Think that at that time those were my first attempts with camilladsp, maybe it is not that difficult after all. Unfortunately I didn't take notes, but I can tell you it is indeed possible

3. I don't know that specific hat. I never tried i2s hats because I consider they are relative expensive and of limited use compared with some very cheap and competent USB cards that you can also use outside the rasp pi world. I suggest you to ask in the camilladsp tutorial in this same forum.

4. Extra info: Eventually I used a pi 4b 2gb instead of the zero 2w and I find the set up much more stable. I used to leave it on literally for weeks with no need to reboot ever.

Hope it helps, good luck!

Awesome - Thanks!

 

[Nicosea]

So what can be done to apply the same correction to the signal coming from the tv? I definitely dont want to spend a lot of money nor i am willing to have to install a big AVR or similar.

I just want to take the toslink from my tv, apply eq, and send it to my dac via spdif (the USB is occupied with the main music streamer)...

My USB is not occupied. Would it be possible to use Hifiberry digi+ I/O hat using only the spdif input and sent to my DAC via raspberry USB (ideally with MoodeAudio)?

 

[MCH]

My USB is not occupied. Would it be possible to use Hifiberry digi+ I/O hat using only the spdif input and sent to my DAC via raspberry USB (ideally with MoodeAudio)?

Hi Nicosea,
You can certainly take the spdif from your tv, process the signal with camilladsp and send it to your dac via usb. You can do it with the hifiberry hat or with any other usb card or interface that has spdif input.
What i think is going to be very difficult, if not impossible, is to use camilladsp implemented in moodeaudio, unless moodeaudio changed this recently.
If you want to do that, i am afraid you will have to use one of the only two hats tha allow it (see post #1).

 

[K3v1]

Hi,
thanks to this and the big CamillaDsp + RPI thread i got a device like in the first post (CM6206) to run a CamillaDSP "Testrig" (Toslink->Front stereo) on a Pi3 from my TV. Only problem I still have is a terrible white noise /static that I get when there is no input signal (if I turn my TV off for example). Is there something that I can do to avoid the white noise going out?