Velbac - Sends audio from a Creative soundcard to another soundcard

Discussion in 'Hardware Discussion & Support' started by Tril, Mar 18, 2007.

  1. Tril

    Tril Triple screen racing ftw

    Go to Velbac webpage to download it

    What it is

    This is a program I made that I called Velbac. It is used to send audio from a Creative soundcard to
    another soundcard.

    Origin of the name

    The name has a meaning. This program is a virtual cable. The names comes from that. V as in virtual and elbac as in cable reversed.

    Supported source sound cards

    The Creative soundcard can be any of them that support "what you hear" through ASIO. I think that the only exception is a Sound Blaster Live 24-bit because it uses a different architecture. It will work with SoundBlaster Live!, Audigy, Audigy 2 and X-Fi.

    Supported source sound cards audio drivers
    On the SBLive! you must use the kX project audio drivers because the drivers from Creative for this card don't support ASIO.

    Audigy and Audigy 2, you can use either the kX project audio drivers or the Creative audio drivers.

    On the X-Fi, you must use the Creative audio drivers.

    It probably also works fine with the YouP PAX drivers on Audigy, Audigy 2 and X-Fi since they are modified Creative drivers but nobody ever tested it until now.

    Why use it
    One use of this program is to get EAX support on a soundcard that does not support it. To do that, you :
    - Configure the default audio playback device of Windows to the Creative sound card.
    - Use Velbac to send the audio from the Creative sound card to another sound card.

    This way, you can have EAX support and send to a card that has higher quality outputs or hardware AC3 encoding.

    The drawback is some added audio latency.

    Tests done on version 1.00

    I tested the program with a Sound Blaster Live! with the kX drivers and an onboard soundcard.
    ROBSCIX tested the program with an Audigy 2 with the Creative and an X-Meridian soundcard.
    A friend of ROBSCIX tested the program with an X-Fi with the Creative and an X-Meridian soundcard.

    It works fine on those three different setups.

    Special thanks
    To ROBSCIX on Guru3D and DriveHeaven. He is the one you can thank for asking me to make this program.


    May cause a BSOD when used together with some specific games. Use at your own risks.
    Last edited: Oct 14, 2007
    Necrosis likes this.
  2. drumphil

    drumphil New Member

    I assume resampling is left up to directx? Any possibility of a higher quality resampling algorithm being built into velbac? I guess this is (part of) why it doesn't presently support asio output?

    edit: also, thanks for a very usefull program.
    Last edited: Mar 20, 2007
  3. Tril

    Tril Triple screen racing ftw

    There's no resampling. It outputs at the frequency of the input.

    There's no ASIO output because it's more complex. We are looking at reading with ASIO on a card and output with ASIO on another card. I started from the ASIO SDK and it does not allow that without some big modifications to the SDK code. The ASIO SDK was made to support only one ASIO driver and only one sound card at a time. It might be possible to modify the code of the SDK to allow that but I have no intention to do that right now.
  4. drumphil

    drumphil New Member

    how does it deal with the difference in sample rate between the clockgens of the two different sound cards? I assumed resamplng would be necessary without wordclock being transmitted from one card to the other (like how creative cards that can't recieve wordclock from spdif inputs handle this). It's not about the difference between 44.1k and 48k, it's about the difference between two different audio clocks running at (nearly) the same rate.. it's the "nearly" that causes the problem, as all clocks run at a slightly different speed, and drift out sync over time, causing audio glitches, and causing the audio streams to drift out of time with each other.

    Thats why I assumed directx was doing the resampling if velbac produced glitch free output. Anyway, if i've got that messed up somehow, please set me straight.
    Last edited: Mar 21, 2007
  5. Tril

    Tril Triple screen racing ftw

    I decided not to do anything. I leave the audio streams drift out of time with each other.

    With WaveOut, I don't know what happens. It probably produces a pop sound once in a while or the delay between the two cards increases.

    With DirectSound, the delay between the two cards caused by DirectSound will never be larger than 75 ms + ASIO latency. I made the buffer used by ASIO a size of 75 ms + ASIO latency. If the difference between the two cards gets too big one way or the other, it will produce a pop sound and it will resync by dropping samples.
  6. drumphil

    drumphil New Member

    thanks for the info. sounds like a reasonable solution given what most people will use this for.
  7. CoolChris

    CoolChris New Member

    Great idea. Tried it on Vista though and it crashes, even using XP compatability.
    Will there be some kind of update to address this please?
  8. classic_leon

    classic_leon New Member

    Great! Super fantastic!
  9. Merc248

    Merc248 New Member

    Awesome program! I found practically no lag in the audio through ASIO. This is with an X-Meridian and an Audigy 2 Platinum on Windows XP SP2.

    However, I registered just now to report a pretty nasty bug: when I try to play S.T.A.L.K.E.R., my computer completely restarts! I've narrowed it down to the case of using Velbac with my Audigy 2 (with the latest drivers as far as I know); it works fine with just the Audigy 2 with Velbac disabled, and it gives an error message right when it starts if I try to use my X-Meridian as the primary card.

    It MIGHT have to do with OpenAL? I'm not sure. S.T.A.L.K.E.R. does indeed use OpenAL, however. I installed the latest OpenAL drivers from and that didn't do a thing. Warcraft III (the only other game I've tested) worked just fine with Velbac.
  10. Tril

    Tril Triple screen racing ftw

    I also got reports that it crashes under F.E.A.R. and Condemned:Criminal Origin. I don't know why.
  11. Socio

    Socio New Member


    If you use an Audigy which has hardware digital decoding then would it be possible to use this app to go from digital out on a cable box, to the Audigy, then have the Audigy decode the digital stream in hardware and then send it to an X-plosion, set to encode to DD 5.1 or pass through if it is a 5.1 signal back to a receiver so that every channel is DD 5.1?

    ROBSCIX New Member

    Yes. This is another use for the application. Let us know how it works for you.
  13. Socio

    Socio New Member

    I tried to get a make shift setup to work but could not get any sound;

    I tried using my old Audigy ZS with my older Audigy Plat internal drive, ( gave the Audigy card to my brother long time ago) so I could have digital coax input on the AudigyZS but I don't think they are compatible as I could not get a signal through the internal drive.

    Hopefully someone else will give this a shot, if it works this would make an upgrade to a X-Fi Elite Pro/ X -Meridian modified pretty damn enticing. :D

    ROBSCIX New Member

    set the AUdigy EXACTLY how you need it set for digital input. Velbac doesn't care what input is working on the Creative card. It pulls the audio from the card and "injects" it into the other.

    tell me exactly how you have Velbac set. You should be able to get this config working...
  15. Socio

    Socio New Member

    The problem is the Audigy 2 ZS does not seem to recognize the older Audigy internal drive which is how I was trying to get digital in from my cable box.

    I will try it again this weekend, I noticed there is a digita I/O in the Audigy 2 ZS I am going to try my old X-mystque extension digital I/O board and see if it recognizes it to test with.

    Side note:
    In the mean time I figured out how to get my analog cable box outs to the line in on my RME card and pass it through WinAMP, then Ozone DSP and back out via the WinAMP KS output to the X-plosion encoded to 5.1 DTS. The digital music channels sound spectacular! 2 channel movies and shows @ 5.1 sound great as well, I get some good bass from them even.

    I wanted to use Audioburst instead but caused lip sync problems where KS out does not, even with Ozone running.

    It would be nice if Velbac can be made to be used as a plug-in in apps like WinAmp someday.

    ROBSCIX New Member

    Never know how it may develop. We are currently working on the Vista version, that is about all I can say about that...
  17. Tril

    Tril Triple screen racing ftw

    You would like Velbac to be an input plugin in Winamp. That's something that's possible to do. I have no experience with Winamp plugins development but I'll try to make an input plugin of Velbac.

    ROBSCIX New Member

    A Winamp plugin? - I am trying to figure out what exactly it would do in a player context?
  19. Tril

    Tril Triple screen racing ftw

    It would work like the line in plugin.

    I just read on the FAQ of Winamp that 5.1 and 7.1 speaker output does not work in Vista with Winamp. A lot of people are switching to Vista so I see no point in developing this as long as it won't work for them. I'll keep this project in mind but I'll put it on hold for now.

    EDIT : I found someone in the Winamp forums saying that 5.1 output works with Winampo 5.33 in Windows Vista as long as the audio drivers support it.
    Last edited: May 30, 2007

    ROBSCIX New Member

    Hmm, I will test that out right now...

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