Second sound card for each individual receiver

[Iz8huj]

I would like to ask if it is possible, and if not already present in the software, to add a second sound card for each single receiver. For example, for digital modes,
I could mute the audio output from the headphones/speakers, but at the same time share the audio of a virtual device with a software for digital modes.
TNX
IZ8HUJ
Michele

[Max]

I would like to ask if it is possible, and if not already present in the software, to add a second sound card for each single receiver. For example, for digital modes,

Michele

Michele, you do not need a second sound card to do this. Each virtual receiver in SDRC can have its own audio output.

What you need to do is download a Virtual Audio Cable. Many people here use VB-Audio:

https://vb-audio.com/Cable/index.htm

For each receiver you can have a different virtual audio cable routed to a different (or multiple instances of the same) digi-decoder like WSJT-X, FLdigi etc. etc.

Optionally you can at the same time listen "across" that cable using Windows "Listen to this device" int he Recording tab of Windows Audio Devices:

Listen.gif (109.75 KiB) Viewed 1018 times

To get to that panel in Windows, press the Windows key, then type "Run" to get to the Run dialogue then enter:

mmsys.cpl

Will bring up the Audio Devices panel.

Alternatively (maybe easier) you can listen to the virtual audio cable output using the free Audio Repeater app from the VAC website. You can get Audio Repeater by downloading the VAC free trial package. It's bundled in the same package. Audio Repeater is free to use without purchase.

https://vac.muzychenko.net/en/manual/repeater.htm

https://vac.muzychenko.net/en/download.htm

Hope it helps.

Max

[Iz8huj]

Thanks for replying. Yes, I also use the Vb-audio virtual cards. I know the listen function, but it doesn't seem very immediate. You understand that every time I have to go into the settings to enable or disable the listen function. While if I had 2 sound cards on the same receiver, I would set one to the speaker output (the default one), and the VB-Audio, used only to transfer the audio to the various software. I don't know if I can make myself understood. I'm attaching an image of another SDR software for simplification purposes only.

SDR_FDM.jpg (30.42 KiB) Viewed 994 times

I was just asking to speed up audio management.

Thanks again, Michele

[jdow]

That will usually cause problems. SDRs face a very nasty problem that creates periodic clicks, usually quite infrequent. With an SDR you have two clocks to satisfy. You have data coming in at some specific rate with some small error, about 100 ppm down to 1 ppm or less. The SDR processes all the data with mathematical precision and presents it to an interface buffer arrangement at the front end's notion of what would be precisely 48,000 samples per second. But, you also have a sound card with ITS notion of what 48,000 samples per second might be, with about the same potential frequency error bands. The smaller the difference between these two errors translates to the SDR having too many buffers or two few buffers to satisfy the sound card's interface timing demands.

Adding a third "thing" into the mess is not going to make it any better. It is not a mess I would expect Simon to adopt, partly because the sets of Windows sound APIs do not lend themselves to serving this kind of .... (ASIO works as well as it does because there is only one sound card (or equivalent) contributing a time clock to the mess. Video software works hard to avoid the problem; but, it mostly politely papers over the glitches if the video clock and sound clock are not precisely related mathematically.) Virtual audio devices deal with these glitches with more or less grace. They are not all the same.

{^_^}

[Max]

I was just asking to speed up audio management.

Thanks again, Michele

Michele, please see the attached image under this text. You will see that you can run multiple instances of Audio Repeater, one for each Virtual Cable. In my example image I have set up one for VAC1 (Audio Repeater 1 or AR1) and one for VAC2 (AR2). Each instance can be started with a named batch file which can then be left on the desktop. Click AR1.bat and you are monitoring VAC1, click AR2.bat and you are monitoring VAC2. I've also shown the text in the bat file. There are two modes for Audio Repeater. One is KS mode and one is MME mode and which version you want to use can be specified in the bat file. You need to read the documentation to see which one you would want to use. I use KS (kernel streaming) which is supposed to offer superior results. You can see that my bat file calls the KS version of the .exe file. I've also attached a copy of my .bat file for you to get you started. You need to be very specific about how you name the VAC, exactly as it appears in Windows Audio Devices of the bat file will show an error when run. This forum interface does not permit the attachment of bat files so I've re-named it to AR1.txt. To use it modify it with your source/playback names and rename the file with the .bat extension instead of .txt.

If you minimise an instance of Audio Repeater it minimises to the Windows Sys Tray. Depends what version of Windows you are running as to whether (when not minimised) multiple instances combine on the Windows taskbar or if they appear separately. If they combine anyway you can leave them all maximised and select from there.

If you want to stop monitoring one of the VACs you select that one in the Sys tray (or on the taskbar) and "quit".

I think this does what you want? Just need to be a bit cautious not to run the same bat file twice or you have two instances of listening to the same VAC but that is obvious from the unpleasant phasing sound.

Hope it helps.

Max

Audio Repeater setup.gif (187.4 KiB) Viewed 975 times