SPDIF in and AC3 - which pins to use

ender` · Feb 18, 2006, 06:53 PM

I've got SoundBlaster Audigy2, and unless I misread something, it should be possible to use it to decode AC3 audio from external source. My only problem is, that the AD_EXT connector on my card doesn't seem to match AUD_EXT connector for which I found diagrams (pin 1 seems to be on the other side).
Are the pins I circled the correct ones to use, or should I count from the other side? Is there any danger in connecting to wrong pins?

Maddogg6 · Feb 18, 2006, 07:51 PM

There are 2 different pinouts - you were using the AUD_EXT pinouts instead of the AD_EXT pinouts -

edited:
So those pins are actually reversed.

Your counting right - just referencing the WRONG pinout diagram

ender` · Feb 18, 2006, 09:48 PM

OK, I searched some more, and found this diagram:

Code:

                               +5V  1>o	  2  -
                               GND  3 o o 4  GND
                         SPDIF0 IN  5 o o 6  GND
                               GND  7 o o 8  GND
                        SPDIF0 OUT  9 o	  10 -
                                 - 11	  12 -
          P16VCLK 24 576 MHz clock 13 o o 14 GND
                     I2S FrameSync 15 o o 16 GND
                      I2S BitClock 17 o o 18 GND
          I2S input to P16V (Aux2) 19 o o 20 GND
 I2S input to P16V (Line-in2/Mic2) 21 o o 22 GND
                GPO1 (GP output 1) 23 o o 24 GPO2 (GP output 2)
                GPO0 (GP output 0) 25 o o 26 GND
                        SPDIF3 OUT 27 o o 28 GND
                        SPDIF1 OUT 29 o o 30 GND
                        SPDIF2 OUT 31 o o 32 GND
                 GPI1 (GP input 1) 33 o o 34 to TAD connector!
                 GPI0 (GP input 0) 35 o o 36 Audio cable detect!
                   UART (MIDI) OUT 37 o o 38 GND
                    UART (MIDI) IN 39 o	  40 -

pins 35 <--> 25 to fake 'AudigyDrive' !

which does seem to correspond to my connectors, and pin 5 says SPDIF0 IN (and I found an XLS file for AD_EXT->LiveDrive, which says the same). This would suggest that I should be able to use pins 5 and 6, or am I missing something?

**dj_stick** · Feb 18, 2006, 09:52 PM

that looks to be the correct pinout for the audigy 2/x-fi AD_EXT header

Maddogg6 · Feb 18, 2006, 09:57 PM

Ok - so long as your certain of the right pinout for your card -

What are you hooking up to this - an external DVD player?
If so - you may need to do something like this:
http://www.andrewkilpatrick.org/mind/spdif/

See the S/PDIF circuits..

It basically cleans up and ensures a good clean SPDIF signal

I was mistaken above - the pins are reversed between AUD_EXT and AD_EXT (GND and SPDIFIN are swapped)

Also: make sure to use 'VIDEO' cable - which will allow longer cable lengths

ender` · Feb 18, 2006, 10:22 PM

PlayStation2 actually - a few games I have support AC3 output on it's optical out, and I got an optical->coax converter from somebody, so I thought I could try playing with 5.1 audio.

Maddogg6 · Feb 18, 2006, 11:17 PM

Well, as long as you:
1) know you have good electrical connections to those PINS
2) Made sure GND connects to GND - and SPDIF to SPDIF (not swapped)

I suspect youll need the additional electronics described in the link I provided -

But - just a few things to check...
1) Do you hear anything when connected? Is it Just 'noise'?
2) Does a popup show to indicate a SPDIF signal is present?
3) Look at the KX - Settings - 'SPDIF I2S Status' screen and see if IT reports any SPDIF signal present.

edit:
Additionally, you could also replace that coax-optical adaptor, and use another DIY project to add optical to the card.
A user here named travelrec has a site here
Choose 'Electronics' link - then 'Application circuit to connect 6 digital INs and 8 OUTs at the AUD_EXT-Connector'

The diagram shows connecting 6 - to an AUD_EXT connector - so some changes would need to be made. - but its another alternative to whats shown in the link I provided in my other post.

ender` · Feb 19, 2006, 04:37 PM

I'm not getting anything in the status screen, so I guess I'll have to build the converter. Thanks for the info.

Feb 18, 2006, 06:53 PM	#1
ender` DriverHeaven Newbie Join Date: Feb 2006 Posts: 4 Rep Power: 0	SPDIF in and AC3 - which pins to use I've got SoundBlaster Audigy2, and unless I misread something, it should be possible to use it to decode AC3 audio from external source. My only problem is, that the AD_EXT connector on my card doesn't seem to match AUD_EXT connector for which I found diagrams (pin 1 seems to be on the other side). Are the pins I circled the correct ones to use, or should I count from the other side? Is there any danger in connecting to wrong pins?

Feb 18, 2006, 07:51 PM	#2
Maddogg6 Tail Razer Join Date: Jun 2005 Location: Bernyurass, AZ - USA Posts: 4,027 Rep Power: 0	There are 2 different pinouts - you were using the AUD_EXT pinouts instead of the AD_EXT pinouts - edited: So those pins are actually reversed. Your counting right - just referencing the WRONG pinout diagram Last edited by Maddogg6; Feb 18, 2006 at 10:00 PM. Reason: Made mistake...

Feb 18, 2006, 09:57 PM	#5
Maddogg6 Tail Razer Join Date: Jun 2005 Location: Bernyurass, AZ - USA Posts: 4,027 Rep Power: 0	Ok - so long as your certain of the right pinout for your card - What are you hooking up to this - an external DVD player? If so - you may need to do something like this: http://www.andrewkilpatrick.org/mind/spdif/ See the S/PDIF circuits.. It basically cleans up and ensures a good clean SPDIF signal I was mistaken above - the pins are reversed between AUD_EXT and AD_EXT (GND and SPDIFIN are swapped) Also: make sure to use 'VIDEO' cable - which will allow longer cable lengths Last edited by Maddogg6; Feb 18, 2006 at 10:10 PM.

Feb 18, 2006, 11:17 PM	#7
Maddogg6 Tail Razer Join Date: Jun 2005 Location: Bernyurass, AZ - USA Posts: 4,027 Rep Power: 0	Well, as long as you: 1) know you have good electrical connections to those PINS 2) Made sure GND connects to GND - and SPDIF to SPDIF (not swapped) I suspect youll need the additional electronics described in the link I provided - But - just a few things to check... 1) Do you hear anything when connected? Is it Just 'noise'? 2) Does a popup show to indicate a SPDIF signal is present? 3) Look at the KX - Settings - 'SPDIF I2S Status' screen and see if IT reports any SPDIF signal present. edit: Additionally, you could also replace that coax-optical adaptor, and use another DIY project to add optical to the card. A user here named travelrec has a site here Choose 'Electronics' link - then 'Application circuit to connect 6 digital INs and 8 OUTs at the AUD_EXT-Connector' The diagram shows connecting 6 - to an AUD_EXT connector - so some changes would need to be made. - but its another alternative to whats shown in the link I provided in my other post. Last edited by Maddogg6; Feb 18, 2006 at 11:24 PM.

Feb 18, 2006, 10:22 PM	Thread Starter #6
ender` DriverHeaven Newbie Join Date: Feb 2006 Posts: 4 Rep Power: 0	PlayStation2 actually - a few games I have support AC3 output on it's optical out, and I got an optical->coax converter from somebody, so I thought I could try playing with 5.1 audio.

Feb 19, 2006, 04:37 PM	Thread Starter #8
ender` DriverHeaven Newbie Join Date: Feb 2006 Posts: 4 Rep Power: 0	I'm not getting anything in the status screen, so I guess I'll have to build the converter. Thanks for the info.