USB-c to USB-c Audio connection of 2 PCs without analogue

[ramdomdude]

Okay, so I’ve been pulling my hair out over this for the past 6 months.
My situation: I have 2 computers, call them A and B, that both run linux that are physically far away (on the order of 10m) from each other. I want to have the audio of A on B. Due to the constrains of reality I have to run any cables right next to power which leads to heavy distortion and interference if I use regular analogue audio cables.

My intend: I would like to transfer the audio from A to B without it ever turning analogue on the way. However neither A nor B have TOS-link and for security reasons I am strongly discouraged from pulse/pipewire-ing it over the network.

What Im looking for is something like a usb c to c cable where the usb controller pretends to be a mic and speaker to the connected devices.
So when I plug one end into A, the controller tells A its a speaker and when I tell the other end into B it tells B its a microphone.
If A now sends the audio to the speaker the controller just pretends like it did the Digital to Analogue conversion and instead passes the digital data over the cable to the other end.
The other end now pretends like it did the Analogue to digital conversion and takes the signal passes the digital signal to B as Microphone input

However I cannot find anything even remotely resembling this. Granted that it doesnt help that google and reddit are completely worthless, since any useful potentially results are completely drowned out by SEO, usb-c phone DAC questions and mountains audiophile digital cable snakeoil.
Does this really not exist? At all? Has anyone solved that issue before?

(Contrary to the thread title I dont actually care about it being specifically c to c it could also be any permutation of a and c)

[AndreiArgeanu]

Have you considered getting a a PCIE card or some kind of DAC that has Toslink and use that to transfer it over? Something like the card below if you have space for it would work well and is affordable, should work with Linux from what info I could find. An external DAC might also be a solution.

[Blue4130]

1 hour ago, ramdomdude said:

Okay, so I’ve been pulling my hair out over this for the past 6 months.
My situation: I have 2 computers, call them A and B, that both run linux that are physically far away (on the order of 10m) from each other. I want to have the audio of A on B. Due to the constrains of reality I have to run any cables right next to power which leads to heavy distortion and interference if I use regular analogue audio cables.

My intend: I would like to transfer the audio from A to B without it ever turning analogue on the way. However neither A nor B have TOS-link and for security reasons I am strongly discouraged from pulse/pipewire-ing it over the network.

What Im looking for is something like a usb c to c cable where the usb controller pretends to be a mic and speaker to the connected devices.
So when I plug one end into A, the controller tells A its a speaker and when I tell the other end into B it tells B its a microphone.
If A now sends the audio to the speaker the controller just pretends like it did the Digital to Analogue conversion and instead passes the digital data over the cable to the other end.
The other end now pretends like it did the Analogue to digital conversion and takes the signal passes the digital signal to B as Microphone input

However I cannot find anything even remotely resembling this. Granted that it doesnt help that google and reddit are completely worthless, since any useful potentially results are completely drowned out by SEO, usb-c phone DAC questions and mountains audiophile digital cable snakeoil.
Does this really not exist? At all? Has anyone solved that issue before?

(Contrary to the thread title I dont actually care about it being specifically c to c it could also be any permutation of a and c)

What is the audio source software wise? Game audio? Music?

[ramdomdude]

28 minutes ago, AndreiArgeanu said:

Have you considered getting a a PCIE card or some kind of DAC that has Toslink and use that to transfer it over? Something like the card below if you have space for it would work well and is affordable, should work with Linux from what info I could find. An external DAC might also be a solution.

I might be able to make it fit but even then I'd need to buy one of those for each PC, at which point Im down 50 bucks+TOSLink cable. Which is a little steep for something thats just supposed to transmit fairly low bandwidth data from A to B

 

19 minutes ago, Blue4130 said:

What is the audio source software wise? Game audio? Music?

all of the above, really. Game audio, music, video/yt. Game audio unfortunately means I dont really have that much latency to spare before things get awkward

[ramdomdude]

Just now, ramdomdude said:

I might be able to make it fit but even then I'd need to buy one of those for each PC, at which point Im down 50 bucks+TOSLink cable. Which is a little steep for something thats just supposed to transmit fairly low bandwidth data from A to B

 

all of the above, really. Game audio, music, video/yt. Game audio unfortunately means I dont really have that much latency to spare before things get awkward

Well I just checked and B only has a single pcie slot, so its either GPU or Soundcard, so thats not really an option.

[adm0n]

13 minutes ago, ramdomdude said:

Well I just checked and B only has a single pcie slot, so its either GPU or Soundcard, so thats not really an option.

You can also get USB sound cards that have TOS-link.

 

If you aren't using the LAN port on those machines, you could also create a network for just those two devices.

[ramdomdude]

4 minutes ago, adm0n said:

You can also get USB sound cards that have TOS-link.

 

If you aren't using the LAN port on those machines, you could also create a network for just those two devices.

From a quick lookaround the usb to audio adapters are about 20-25 bucks each so actually about just as much as the pcie card, which now is at least an option but still kind of steep for how stupid of a problem this solves >.>

Unfortunately I do use the LAN ports and I only have one each, so thats not an option.

[adm0n]

43 minutes ago, ramdomdude said:

From a quick lookaround the usb to audio adapters are about 20-25 bucks each so actually about just as much as the pcie card, which now is at least an option but still kind of steep for how stupid of a problem this solves >.>

Unfortunately I do use the LAN ports and I only have one each, so thats not an option.

Well, since you have them over 5 meters apart, you won't have another option then to buy some sort of adapter. You can also buy a cheap USB - LAN adapter  ~$10 each and a 10m long cable (or USB - Wifi adapter, but this might add latency and/or stability issues), but then you have to deal with setting up the network and the software to send/receive the data. Other than Lan cables or optical cables, I can't think of anything, that'd work over 10 meters.

 

You could probably make due with an active USB2 cable, but they are also not cheap. And you'd either need to write your own software or check if someone has pre written something for you.

 

I think the easiest thing for you would just be sending the data via the existing network. if the latency is not a problem for you and just encrypt it somehow.

[AndreiArgeanu]

53 minutes ago, ramdomdude said:

From a quick lookaround the usb to audio adapters are about 20-25 bucks each so actually about just as much as the pcie card, which now is at least an option but still kind of steep for how stupid of a problem this solves >.>

Unfortunately I do use the LAN ports and I only have one each, so thats not an option.

Might be able to use HDMI instead. One 15$ adaptor or more like 7-8$ if you get it of aliexpress if you don't mind the waiting times and an HDMI cable and you get a headphone jack and toslink output on the other side, and possibly one of those dummy HDMI dongles, I'm not sure if these things work without a display attached to them.

[mariushm]

You could get an active USB extension cable (to have lengths longer than 3-5 meters), or a fiber based usb extension ... plug it in the remote pc, plug a usb based DAC / soundcard with coax/optical out at the end of the cable, and plug the dac into the Line In of your computer or coax / toslink input .  

The data goes digitally on the usb cable, so it's shielded and it's digital transfer so won't be corrupted, gets decoded by the DAC near your computer to analogue and goes into your sound card. You could use a small cable of a few inches between the DAC and your card's Line In, so minimal opportunity to add hiss or something. 

 

You could try getting a USB soundcard with digiktal coax / toslink inputs 

 

There's also stuff like  https://hifimediy.com/product/hifime-ur23-spdif-optical-to-usb-converter/

 

 

[ramdomdude]

1 hour ago, adm0n said:

Well, since you have them over 5 meters apart, you won't have another option then to buy some sort of adapter. You can also buy a cheap USB - LAN adapter  ~$10 each and a 10m long cable (or USB - Wifi adapter, but this might add latency and/or stability issues), but then you have to deal with setting up the network and the software to send/receive the data. Other than Lan cables or optical cables, I can't think of anything, that'd work over 10 meters.

 

You could probably make due with an active USB2 cable, but they are also not cheap. And you'd either need to write your own software or check if someone has pre written something for you.

 

I think the easiest thing for you would just be sending the data via the existing network. if the latency is not a problem for you and just encrypt it somehow.

Yeah, I think I need to look into the ethernet thing more.

1 hour ago, mariushm said:

You could get an active USB extension cable (to have lengths longer than 3-5 meters), or a fiber based usb extension ... plug it in the remote pc, plug a usb based DAC / soundcard with coax/optical out at the end of the cable, and plug the dac into the Line In of your computer or coax / toslink input .  

The data goes digitally on the usb cable, so it's shielded and it's digital transfer so won't be corrupted, gets decoded by the DAC near your computer to analogue and goes into your sound card. You could use a small cable of a few inches between the DAC and your card's Line In, so minimal opportunity to add hiss or something. 

 

You could try getting a USB soundcard with digiktal coax / toslink inputs 

 

There's also stuff like  https://hifimediy.com/product/hifime-ur23-spdif-optical-to-usb-converter/

 

 

Alternatively I think Im going to chain DACs into each other however asinine it feels to me to do digital A -> DAC -> analogue -> ADC -> digital B for no other reason than to bridge a gap.

1 hour ago, AndreiArgeanu said:

Might be able to use HDMI instead. One 15$ adaptor or more like 7-8$ if you get it of aliexpress if you don't mind the waiting times and an HDMI cable and you get a headphone jack and toslink output on the other side, and possibly one of those dummy HDMI dongles, I'm not sure if these things work without a display attached to them.

Thats an interesting idea, I think all you really need to do is to bridge the display connection pins, I know that at least on linux it will send audio regardless of if there is display data flowing

[Blue4130]

44 minutes ago, ramdomdude said:

Yeah, I think I need to look into the ethernet thing more.

Alternatively I think Im going to chain DACs into each other however asinine it feels to me to do digital A -> DAC -> analogue -> ADC -> digital B for no other reason than to bridge a gap.

Thats an interesting idea, I think all you really need to do is to bridge the display connection pins, I know that at least on linux it will send audio regardless of if there is display data flowing

It sounds like you need a mixer, not a DAC... What are you doing this for? Streaming?

[ramdomdude]

Not particularly for streaming, all I need is to get audio from one PC into another but I cant use aux because they are far away and because the way the rooms turned out I have to put every wire next to the powerline, which is absolutely no problem with digital signals but ruins analogue ones.

Am I misunderstanding what a mixer does? As far as i thought a mixer just combines audiosignals with some of them having to ability to mess with the frequencies and stuff while at it. Here this is part of what computer B would do