[linux-audio-user] connecting soundcards using JACK

e. j. branagan - the MUSE laug at themusenashville.com
Sun Nov 7 23:09:55 EST 2004

Jeroen Wijnhout wrote:

>Hi all,
>Would it be possible to connect my IMic USB soundcard capture port to the 
>onboard AC97 soundcard using JACK? I'm able to connect ports of a single 
>soundcard to each other, however I would like to be able to listen via the 
>onboard card what I'm recording on the external USB soundcard.
>It seems that I have to start the JACK daemon in such a way that it can talk 
>to both soundcards at the same time.
>jackd -V:0.94.0
Jack will only accept one sound card at a time.
That can be a 'virtual' soundcard defined in .asourdrc, but unless you 
can sync the cards,
jack will eventually crash anyway.  For instance, think about what 
happens if your
playback card is running at 44100 hz and your recording card at 44102 hz.

Lacking a wordclock, SMPTE or spdif connetion between sound devices, 
your probably
out of luck.

BTW, with soundblaster 16 ISA cards it is possible to sync multiple 
cards, by snipping
the crystal from all but one, and jumpering from the remaining crystal 
to all the cards.
I presume this will work with other cards as well, but probably only if 
they are
identical or really similar.  But I'm going to stick with my Maudio 1010.

e. j. branagan
the MUSE § Nashville, TN

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