semi-pro PCI snd crd for linux

[Lennart Sorensen]

On Sun, Sep 02, 2007 at 01:20:25PM -0400, Chris Aitken wrote:
> Chris Aitken wrote:
> 
> Sorry, I'm top-posting to make an apology and explanation for reviving 
> this thread. I lost the responses I got to this post. I did a clean 
> install (fedora) to give me the kernel and alsa versions I need for a 
> semi-pro sound card. The backup I had to re-construct my mail (which was 
> an adventure)from was old as we moved and I accumulated a lot of email 
> before I got the backup machine set up again. 'nuff said.
> 
> I did buy (and physically install) the EMU 1212 M PCI sound card. I have 
> eight business days now to get this working under linux (I've been 
> drywalling my home recording studio) before I send it back (30-day 
> return) to L&McQ.
> 
> It's being detected as the Creative Labs SB Audigy, but no sound comes 
> out of it. The first thing I had to wrap my mind around was that it has 
> no 'spkr' output. I assume the 1/4" OUTs are what go the speakers. 
> Someone on this list (Lennart?) explained to me (IIRC) that I can't just 
> "trivially" (meaning, I guess, that it /looks/ connected but it ain't 
> done /right)/ hook up the sound card OUT to speakers - they must be 
> balanced (TRS) 1/4" ends. I understand now that "stereo", "balanced" and 
> "TRS" (tip, ring, sleeve) are synonymous. So, I have a 1/4" male 
> -to-1/8" female adaptor from the sound card to the TRS 1/8" male that 
> goes to the PC speakers. Still no sound. The speakers do work as I can 
> get sound from the onboard card (which I thought I disabled in the BIOS, 
> but just seems to be only a tab selection away from testing in the GUI 
> System>Administration>Soundcard Detection).

No stereo is an incompatible use of the same connector.  You need the
adapters that either connect each of the outputs to a standard RCA phono
jack (remember the card has seperate left and right channel outputs).
Or you need a cable that connects to both outputs and provides the 1/8"
stereo jack you are used to on PCs.  EMU's website has a picture in the
accessories of the second one.

TRS and balanced is the same thing.  What the adapters do is simply use
the reference ground and one side of the balanced signal to give you a
regular unbalanced signal (the other half is not connected).

If you try to connect normal PC speakers to just one connector with a
1/4" to 1/8" adapter you will either short something, or you will simply
have both speakers playing one channel except out of phase (essentially
trying to cancel each other out).

Being detected as an Audigy is kind of reasonable since the 1212m is
actually based on the same emu10002 chip as the audigy but uses
additional chips that the audigy doesn't have along with much higher
quality components to give better sound quality.

> I will test the 1/4" male -to-1/8" female adaptor (that I have in the 
> soundcard) to make sure it works. I'll go to alsa-projects.org again to 
> see how to get the card working under linux. There also is a good hacker 
> working in the local Krazy Krazy who might take this on. So, I need to 
> do all I can quickly, so I can it to him, see what he can do, and still 
> have time to get it back to L&McQ by Sept 17.

Other than the cable, remember you must have 1.0.14 ALSA version (not
1.0.13 or 1.0.14rc).  And you need the alsa-firmware 1.0.14 in order to
get the fpga code required by the card to work fully.

--
Len Sorensen
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