Can't turn off "digital output only" - won't toggle

eddie173 · Sep 23, 2006, 08:16 PM

I'm just getting started with kX and for some reason when I click to toggle "digital output only" nothing happens, and I'm stuck with it on, even though I've got a CT4832 and standard destop computer speakers which are certainly not digital...

I'd be happy to provide addiitonal information if someone wouldn't mind helping me out I'd really appreciate it. Living in silence...

Russ · Sep 23, 2006, 08:56 PM

What version of kX are you using?

stuff-x · Nov 16, 2006, 05:30 PM

have the same problem

...with XP... ME worked fine....

chris.miller · Nov 17, 2006, 10:50 AM

reset device settings and if that doesn't work, reset global settings

Maddogg6 · Nov 17, 2006, 04:58 PM

My test - with SAME SBLive model...

DOO DOES work - if using Epilog... but DOO on ProFx/KXLt -- does not work.

If I enable DOO with KXLt - analog output is still active. Digital output is always active no matter the state of the DOO switch.

So it appears this is a ProFx bug and not a KX one.. ?? Must have some model specific code missing or something in KXlt..??

Use Epilog instead of KXLt (maybe need to reset device as I did as a shortcut to reset DSP as well an what ever else it resets.)

Russ · Nov 17, 2006, 06:18 PM

@Maddogg6
How are you toggling DOO mode?
i.e.
Are you using the button in kXlt, or are you using the button in kX Mixer?

Does the button in kX Mixer toggle it correctly, when using kXlt.

You can also use kX Console to toggle DOO mode:
DOO disabled: shw 0 0
DOO enabled: shw 0 1

Does it work if you use the above kX Console commands to do it (using kXlt)?

Maddogg6 · Nov 17, 2006, 06:33 PM

Doh.. I should have thought of that...

Ok - further testing....
All ways (mixer, KXLt and console) of toggleing DOO, ONLY works for the physical 'front' output. NOT the physical rear. (which I assusme most people are using for 'front'.

In other words this behaviour is not affected by the toggle front <> Rear.

Russ · Nov 17, 2006, 06:39 PM

BTW: Remember that kX Mixer does not auto-refresh it's pages, so make sure you force a refresh when toggling DOO mode within kXlt. Also, kXlt's indicator can/does on occasion get out of sync with the kX Mixer's setting (and does not refresh itself (even when opening/closing the GUI)), but when you toggle the state again (in kXlt) it does re-sync itself (i.e. it reads the setting, and if it does not match the hardware setting, it toggles it's state, but not the hardware state (at least that is what it appears to do)).

Quote:

Originally Posted by Maddogg6

Doh.. I should have thought of that...

Ok - further testing....
All ways (mixer, KXLt and console) of toggleing DOO, ONLY works for the physical 'front' output. NOT the physical rear. (which I assusme most people are using for 'front'.

In other words this behaviour is not affected by the toggle front <> Rear.

And the above is only when using kXlt? or with epilog too?
A plugin should only need to tell kX to turn it on/off, and kX should handle it, so I am not sure why it would work with epilog, but not with kXlt (maybe it works a little differently for your card (as compared with my card), since the digital out jack is not shared with any analog channels (i.e. maybe the muting is done in the DSP and not an actual hardware setting)).

Maddogg6 · Nov 17, 2006, 07:22 PM

Epilog works as expected for the rears if I use default DSP config..

But after I reconfig the 4832's DSP - and keep same epilog loaded but use Profx/Src - MX6 - it stops working...

And whats even weirder - My SB350 Mixy8x2 - changed level on track 1 left side only (it wasnt me anyway, becuase they are' locked' as stereo..??) - I noticed this after making changes in my other card.
Will have to watch this more closely.

But somethings not quite right somewhere.

Any more tests I can do to help pinpoint the problem (well, its no biggy to me becuase I normally only use the spdif out to my SB350 anyway, but for others..)??

Russ · Nov 17, 2006, 07:36 PM

With your card, digital output should always be enabled, right? So, toggling DOO mode on your card does what it says, it toggles between digital output only, and analog/digital (both)? i.e. There is no reason to disable digital output on your card, right? (it is different with my card (because of the shared jack), and it toggles between digital output only and analog output only).

If the above is correct, then the only issue would be, whether or not the analog channels are muted/unmuted correctly. So, if I am understanding you correctly, then the problem would be that analog rear is not muted when enabling DOO mode, is this correct?

Russ · Nov 17, 2006, 07:42 PM

Quote:

Originally Posted by Maddogg6

And whats even weirder - My SB350 Mixy8x2 - changed level on track 1 left side only (it wasnt me anyway, becuase they are' locked' as stereo..??) - I noticed this after making changes in my other card.
Will have to watch this more closely.

Mixy plugins probably should not be directly connected to FxBus, since it uses input registers more than once in it's code.

Maddogg6 · Nov 17, 2006, 08:43 PM

Quote:

Originally Posted by Russ

Mixy plugins probably should not be directly connected to FxBus, since it uses input registers more than once in it's code.

Ahh - ok, good to know...

Also, yes, Digital is ALWAYS on for me. - thus why I mentioned its not a big problem for me personally - but obviously it is for the OP..I was just glad to have a common card model I could verify/test with in this case.

BUT - only with default dsp (so far in my limited testing) does DOO work by muting the physical rear output.

Russ · Nov 17, 2006, 09:15 PM

Quote:

Originally Posted by Maddogg6

Also, yes, Digital is ALWAYS on for me. - thus why I mentioned its not a big problem for me personally - but obviously it is for the OP..I was just glad to have a common card model I could verify/test with in this case.

Ok, so I would guess that this is normal for that card model, but I would be curious to know if it is the same with the CL driver.

Quote:

BUT - only with default dsp (so far in my limited testing) does DOO work by muting the physical rear output.

That part seems strange to me, as I would think that it would either work, or it wouldn't work (i.e. muting AC97 hardware registers, although again, maybe it is different with your card). What happens if you disconnect analog rear in the DSP (maybe the signal is bleeding in from somewhere else?)?

Maddogg6 · Nov 17, 2006, 09:34 PM

well - further testing suggests somethings wackey..lol

It will work at times with epilog and mixer switch for rear physical... but other times it is not. Maybe IS bleeding somehow??

I need to play around more (change my other cards DSP to not use mixy - ie, romove otherknown potential causes of problems)

(or the act of swapping plugs as I am - as opposed to monitoring ALL outputs at same time.. aka 'jack sensing' or something else completely un related.???)

Russ · Nov 17, 2006, 09:47 PM

Another thing you can can do, is use kX Console to read the ac97 registers for front/rear volume, and see if it is muting/unmuting it.

From looking at the datasheet for your codec (CS4297A) it appears to be register's 02 and 04.

In any case, I am just trying to give you some ideas of things to check out, etc.

Tril · Nov 18, 2006, 12:58 AM

I also have a CT4832. If I activate and deactivate "digital output only", it does not get stuck on. I'm using the button on the mixer and I use epilog in the DSP and no ProFX plugins.

Make sure that you have the latest ProFX plugins. It's possible that an older version is included in the 3538l release of the kX drivers.

Maddogg6 · Nov 18, 2006, 02:08 AM

Ok - I checked those registers (2 & 4)
It seems its possible the ac97 device isnt detected correctly or something..

Reg #4 goes unchanged when DOO is ON and the output IS muted with default DSP.

Ill keep looking at the registers to see if I can see a patern develop... but I wouldnt hold my breath too long - lol (but you know that

)

@Trill:
Yup I have latest profex that fixed the released one with the skin bug with the ADC.

Maddogg6 · Nov 18, 2006, 02:13 AM

Ok - to make my life al little easier... any hint how to append output

Im trying to make a batch file to redirect resut to be sent to a text file - but each time overwrites the results.txt file.
Example
kxctrl.exe -gac97 2 > results.txt
kxctrl.exe -gac97 4 > results.txt

So the text file only contains the last result.

edit: nevermind found it..
kxctrl.exe -gac97 2 >> results.txt (I knew it was possible..

)

Russ · Nov 18, 2006, 03:21 AM

I am not sure about register 04, it is just that I did not see anything else in the datasheet (it is register 36h on my card). You could try writing 8000 to that register (sac97 4 8000), and see if that mutes analog rear.

Maddogg6 · Nov 18, 2006, 03:26 AM

OK - it does seem to be a definite problem with DOO and ProFx/KXlt.

<edit:> ProFx/Kxlt - is NOT designed to mut the physical rear output. So it not a bug or a 'problem' - just a misunderstood 'feature' to avoid feedback loops when some cards use same AC97 device for inputs and outputs. But was NOT meant to be a convenient way to simply mute analog out alone. <end edit>

I can repeatably...
Start with default DSP config. - DOO works fine

Reconfig DSP - keeping epilog - DOO stops working

After playing around - Eplilog - starts working
(I suspect the act of reading registers w/ kxctrl - causes this ??)

I took readings of all registers in each of my test... but to be honest, Im not sure what it all means to me.. Other than it seems the register affected by the rear volume is not 4 but others are I didnt expect..??
<edit:> Disreguard the KXlt results below as they are moot, see above edit <end edit>

HTML Code:

 <table cellspacing="0" cellpadding="0">
  <tr>
    <td width="107">Plugin</td>
    <td width="137">EPILOG</td>
    <td width="127">EPILOG</td>
    <td width="149">EPILOG</td>
    <td width="126">KXlt</td>
    <td width="129">KXlt</td>
  </tr>
  <tr>
    <td>DOO</td>
    <td>ON</td>
    <td>OFF</td>
    <td>ON</td>
    <td>ON</td>
    <td>OFF</td>
  </tr>
  <tr>
    <td>Switched by</td>
    <td>Mixer</td>
    <td>Mixer</td>
    <td>Mixer</td>
    <td>Kxlt</td>
    <td>Mixer</td>
  </tr>
  <tr>
    <td>Status</td>
    <td>Working</td>
    <td>Working</td>
    <td>NOT WORKING</td>
    <td>NOT WORKING</td>
    <td>NOT WORKING</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=0]=1990</td>
    <td>AC97[reg=0]=1990</td>
    <td>AC97[reg=0]=1990</td>
    <td>AC97[reg=0]=1990</td>
    <td>AC97[reg=0]=1990</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=2]=9f1f</td>
    <td>AC97[reg=2]=0</td>
    <td>AC97[reg=2]=9f1f</td>
    <td>AC97[reg=2]=9f1f</td>
    <td>AC97[reg=2]=0</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=4]=8000</td>
    <td>AC97[reg=4]=8000</td>
    <td>AC97[reg=4]=8000</td>
    <td>AC97[reg=4]=8000</td>
    <td>AC97[reg=4]=8000</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=6]=801f</td>
    <td>AC97[reg=6]=801f</td>
    <td>AC97[reg=6]=801f</td>
    <td>AC97[reg=6]=801f</td>
    <td>AC97[reg=6]=801f</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=a]=1e</td>
    <td>AC97[reg=a]=801e</td>
    <td>AC97[reg=a]=1e</td>
    <td>AC97[reg=a]=1e</td>
    <td>AC97[reg=a]=801e</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=c]=1e</td>
    <td>AC97[reg=c]=801e</td>
    <td>AC97[reg=c]=1e</td>
    <td>AC97[reg=c]=1e</td>
    <td>AC97[reg=c]=801e</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=e]=1e</td>
    <td>AC97[reg=e]=801e</td>
    <td>AC97[reg=e]=1e</td>
    <td>AC97[reg=e]=1e</td>
    <td>AC97[reg=e]=801e</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=10]=8</td>
    <td>AC97[reg=10]=8008</td>
    <td>AC97[reg=10]=1e</td>
    <td>AC97[reg=10]=1e</td>
    <td>AC97[reg=10]=801e</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=12]=808</td>
    <td>AC97[reg=12]=8808</td>
    <td>AC97[reg=12]=808</td>
    <td>AC97[reg=12]=808</td>
    <td>AC97[reg=12]=8808</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=14]=808</td>
    <td>AC97[reg=14]=8808</td>
    <td>AC97[reg=14]=808</td>
    <td>AC97[reg=14]=808</td>
    <td>AC97[reg=14]=8808</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=16]=808</td>
    <td>AC97[reg=16]=8808</td>
    <td>AC97[reg=16]=808</td>
    <td>AC97[reg=16]=808</td>
    <td>AC97[reg=16]=8808</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=18]=9f1f</td>
    <td>AC97[reg=18]=808</td>
    <td>AC97[reg=18]=9f1f</td>
    <td>AC97[reg=18]=9f1f</td>
    <td>AC97[reg=18]=808</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=1a]=505</td>
    <td>AC97[reg=1a]=404</td>
    <td>AC97[reg=1a]=505</td>
    <td>AC97[reg=1a]=505</td>
    <td>AC97[reg=1a]=404</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=1c]=0</td>
    <td>AC97[reg=1c]=0</td>
    <td>AC97[reg=1c]=0</td>
    <td>AC97[reg=1c]=0</td>
    <td>AC97[reg=1c]=0</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=20]=200</td>
    <td>AC97[reg=20]=200</td>
    <td>AC97[reg=20]=200</td>
    <td>AC97[reg=20]=200</td>
    <td>AC97[reg=20]=200</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=22]=0</td>
    <td>AC97[reg=22]=0</td>
    <td>AC97[reg=22]=0</td>
    <td>AC97[reg=22]=0</td>
    <td>AC97[reg=22]=0</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=26]=f</td>
    <td>AC97[reg=26]=f</td>
    <td>AC97[reg=26]=f</td>
    <td>AC97[reg=26]=f</td>
    <td>AC97[reg=26]=f</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=28]=200</td>
    <td>AC97[reg=28]=200</td>
    <td>AC97[reg=28]=200</td>
    <td>AC97[reg=28]=200</td>
    <td>AC97[reg=28]=200</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=2c]=bb80</td>
    <td>AC97[reg=2c]=bb80</td>
    <td>AC97[reg=2c]=bb80</td>
    <td>AC97[reg=2c]=bb80</td>
    <td>AC97[reg=2c]=bb80</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=32]=bb80</td>
    <td>AC97[reg=32]=bb80</td>
    <td>AC97[reg=32]=bb80</td>
    <td>AC97[reg=32]=bb80</td>
    <td>AC97[reg=32]=bb80</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=5e]=80</td>
    <td>AC97[reg=5e]=80</td>
    <td>AC97[reg=5e]=80</td>
    <td>AC97[reg=5e]=80</td>
    <td>AC97[reg=5e]=80</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=60]=22</td>
    <td>AC97[reg=60]=22</td>
    <td>AC97[reg=60]=22</td>
    <td>AC97[reg=60]=22</td>
    <td>AC97[reg=60]=22</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=68]=0</td>
    <td>AC97[reg=68]=0</td>
    <td>AC97[reg=68]=0</td>
    <td>AC97[reg=68]=0</td>
    <td>AC97[reg=68]=0</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=7c]=4352</td>
    <td>AC97[reg=7c]=4352</td>
    <td>AC97[reg=7c]=4352</td>
    <td>AC97[reg=7c]=4352</td>
    <td>AC97[reg=7c]=4352</td>
  </tr>
  <tr>
    <td></td>
    <td>AC97[reg=7e]=5913</td>
    <td>AC97[reg=7e]=5913</td>
    <td>AC97[reg=7e]=5913</td>
    <td>AC97[reg=7e]=5913</td>
    <td>AC97[reg=7e]=5913</td>
  </tr>
  <tr>
    <td rowspan="4">NOTES:</td>
    <td>Default DSP</td>
    <td>Default DSP</td>
    <td>Cleared DSP and rebuild</td>
    <td>Replaced epilog w</td>
    <td>Refreshed DOO status</td>
  </tr>
  <tr>
    <td></td>
    <td></td>
    <td>using SRC &amp; MX6</td>
    <td>KXlt</td>
    <td>in mixer prior to test</td>
  </tr>
  <tr>
    <td></td>
    <td></td>
    <td>Simple config for test</td>
    <td></td>
    <td>Then set DOO in mixer</td>
  </tr>
  <tr>
    <td></td>
    <td></td>
    <td>Only</td>
    <td></td>
    <td></td>
  </tr>
</table>

PS - copy and paste this to a text file and rename to results.html - theno open in a browser for it to be formatted to make sense.

Sep 23, 2006, 08:16 PM	#1
eddie173 DriverHeaven Newbie Join Date: Sep 2006 Posts: 1 Rep Power: 0	Can't turn off "digital output only" - won't toggle I'm just getting started with kX and for some reason when I click to toggle "digital output only" nothing happens, and I'm stuck with it on, even though I've got a CT4832 and standard destop computer speakers which are certainly not digital... I'd be happy to provide addiitonal information if someone wouldn't mind helping me out I'd really appreciate it. Living in silence...

Nov 17, 2006, 07:36 PM	#10
Russ HardwareHeaven Extreme Member Join Date: Jan 2005 Posts: 5,507 Rep Power: 61	With your card, digital output should always be enabled, right? So, toggling DOO mode on your card does what it says, it toggles between digital output only, and analog/digital (both)? i.e. There is no reason to disable digital output on your card, right? (it is different with my card (because of the shared jack), and it toggles between digital output only and analog output only). If the above is correct, then the only issue would be, whether or not the analog channels are muted/unmuted correctly. So, if I am understanding you correctly, then the problem would be that analog rear is not muted when enabling DOO mode, is this correct? Last edited by Russ; Nov 17, 2006 at 07:55 PM. Reason: typo

Nov 18, 2006, 02:13 AM	#18
Maddogg6 Tail Razer Join Date: Jun 2005 Location: Bernyurass, AZ - USA Posts: 4,027 Rep Power: 50	Ok - to make my life al little easier... any hint how to append output Im trying to make a batch file to redirect resut to be sent to a text file - but each time overwrites the results.txt file. Example kxctrl.exe -gac97 2 > results.txt kxctrl.exe -gac97 4 > results.txt So the text file only contains the last result. edit: nevermind found it.. kxctrl.exe -gac97 2 >> results.txt (I knew it was possible..)

Sep 23, 2006, 08:56 PM	#2
Russ HardwareHeaven Extreme Member Join Date: Jan 2005 Posts: 5,507 Rep Power: 61	What version of kX are you using?

Nov 16, 2006, 05:30 PM	#3
stuff-x DriverHeaven Newbie Join Date: Aug 2006 Posts: 1 Rep Power: 0	have the same problem ...with XP... ME worked fine....

Nov 17, 2006, 10:50 AM	#4
chris.miller DriverHeaven Newbie Join Date: Jul 2006 Posts: 14 Rep Power: 0	reset device settings and if that doesn't work, reset global settings

Nov 17, 2006, 04:58 PM	#5
Maddogg6 Tail Razer Join Date: Jun 2005 Location: Bernyurass, AZ - USA Posts: 4,027 Rep Power: 50	My test - with SAME SBLive model... DOO DOES work - if using Epilog... but DOO on ProFx/KXLt -- does not work. If I enable DOO with KXLt - analog output is still active. Digital output is always active no matter the state of the DOO switch. So it appears this is a ProFx bug and not a KX one.. ?? Must have some model specific code missing or something in KXlt..?? Use Epilog instead of KXLt (maybe need to reset device as I did as a shortcut to reset DSP as well an what ever else it resets.)

Nov 17, 2006, 06:18 PM	#6
Russ HardwareHeaven Extreme Member Join Date: Jan 2005 Posts: 5,507 Rep Power: 61	@Maddogg6 How are you toggling DOO mode? i.e. Are you using the button in kXlt, or are you using the button in kX Mixer? Does the button in kX Mixer toggle it correctly, when using kXlt. You can also use kX Console to toggle DOO mode: DOO disabled: shw 0 0 DOO enabled: shw 0 1 Does it work if you use the above kX Console commands to do it (using kXlt)?

Nov 17, 2006, 06:33 PM	#7
Maddogg6 Tail Razer Join Date: Jun 2005 Location: Bernyurass, AZ - USA Posts: 4,027 Rep Power: 50	Doh.. I should have thought of that... Ok - further testing.... All ways (mixer, KXLt and console) of toggleing DOO, ONLY works for the physical 'front' output. NOT the physical rear. (which I assusme most people are using for 'front'. In other words this behaviour is not affected by the toggle front <> Rear.

Nov 17, 2006, 07:22 PM	#9
Maddogg6 Tail Razer Join Date: Jun 2005 Location: Bernyurass, AZ - USA Posts: 4,027 Rep Power: 50	Epilog works as expected for the rears if I use default DSP config.. But after I reconfig the 4832's DSP - and keep same epilog loaded but use Profx/Src - MX6 - it stops working... And whats even weirder - My SB350 Mixy8x2 - changed level on track 1 left side only (it wasnt me anyway, becuase they are' locked' as stereo..??) - I noticed this after making changes in my other card. Will have to watch this more closely. But somethings not quite right somewhere. Any more tests I can do to help pinpoint the problem (well, its no biggy to me becuase I normally only use the spdif out to my SB350 anyway, but for others..)??

Nov 17, 2006, 09:34 PM	#14
Maddogg6 Tail Razer Join Date: Jun 2005 Location: Bernyurass, AZ - USA Posts: 4,027 Rep Power: 50	well - further testing suggests somethings wackey..lol It will work at times with epilog and mixer switch for rear physical... but other times it is not. Maybe IS bleeding somehow?? I need to play around more (change my other cards DSP to not use mixy - ie, romove otherknown potential causes of problems) (or the act of swapping plugs as I am - as opposed to monitoring ALL outputs at same time.. aka 'jack sensing' or something else completely un related.???)

Nov 17, 2006, 09:47 PM	#15
Russ HardwareHeaven Extreme Member Join Date: Jan 2005 Posts: 5,507 Rep Power: 61	Another thing you can can do, is use kX Console to read the ac97 registers for front/rear volume, and see if it is muting/unmuting it. From looking at the datasheet for your codec (CS4297A) it appears to be register's 02 and 04. In any case, I am just trying to give you some ideas of things to check out, etc.

Nov 18, 2006, 12:58 AM	#16
Tril S-3D enthusiast Join Date: Sep 2004 Location: Canada Posts: 1,675 Rep Power: 63 System Specs	I also have a CT4832. If I activate and deactivate "digital output only", it does not get stuck on. I'm using the button on the mixer and I use epilog in the DSP and no ProFX plugins. Make sure that you have the latest ProFX plugins. It's possible that an older version is included in the 3538l release of the kX drivers.

Nov 18, 2006, 02:08 AM	#17
Maddogg6 Tail Razer Join Date: Jun 2005 Location: Bernyurass, AZ - USA Posts: 4,027 Rep Power: 50	Ok - I checked those registers (2 & 4) It seems its possible the ac97 device isnt detected correctly or something.. Reg #4 goes unchanged when DOO is ON and the output IS muted with default DSP. Ill keep looking at the registers to see if I can see a patern develop... but I wouldnt hold my breath too long - lol (but you know that ) @Trill: Yup I have latest profex that fixed the released one with the skin bug with the ADC.

Nov 18, 2006, 03:21 AM	#19
Russ HardwareHeaven Extreme Member Join Date: Jan 2005 Posts: 5,507 Rep Power: 61	I am not sure about register 04, it is just that I did not see anything else in the datasheet (it is register 36h on my card). You could try writing 8000 to that register (sac97 4 8000), and see if that mutes analog rear.