AC3 from Laserdiscs: Asus Xonar D2 or Auzentech X-Fi Prelude 7.1

[Herrie1982]

I'd like to rip AC3 Dolby Digital and PCM Stereo from a number of laserdiscs. I've got a RF Demodulator for AC3 so I should be able to capture this using coax and the PCM Stereo I'd like to capture using optical.

I found the following 2 cards with PCI Interface with both optical and coax in
Auzentech X-Fi Prelude 7.1: http://www.auzentech.com/site/products/x-fi_prelude.php#specifications
Asus Xonar D2/PM: http://www.asus.com/product.aspx?P_ID=QsEKBPr6ko9pFF2D&templete=2

I understood that to rip AC3 the card should be "bit-accurate". The Asus is approx. EUR 50,- cheaper and for the rest I believe the specs are pretty much similar.

I use Windows 7 64 bits.

Which of the 2 cards would you recommend me and why?

[INFRATOM]

I can tell you which one not to buy. I have the Auzentech and very much regret to have bought it not just because the hardware is bad but when you install the driver a spyware is installed and they even state it in the license agreement that as a payoff for license we collect information. Also all kind of license manager would be running and at the time it would not install or update the driver without Internet connection. Worse it has a protection that if you remove the hardware for any reason the driver would lockup and to get it to work you need a HD reformat and a new OS install. All the DTS live and Dolby live is only for feed to audio amp and cannot do anything with it inside the computer. All these protections are for Creative license so you might as well buy the creative or go for Pro stuff. I again say I regret to have bought Auzentech I should have bought ASUS which I think would have been better.

[Nelson37]

The only one I know for sure works is the Creative X-Fi card. Not at all sure how the RF demodulator figures into this. You need direct SPDIF output.

[edDV]

The only one I know for sure works is the Creative X-Fi card. Not at all sure how the RF demodulator figures into this. You need direct SPDIF output.

Exactly. AC3 requires S/PDIF. PCM will be two channel stereo.

RF? would be MTS (maybe Dolby B) stereo.

[Herrie1982]

Thanks guys for your feedback so far!

Regarding AC-3 on Laserdiscs: (straight from the Laserdisc Wiki)

"Unlike DVDs, which carry Dolby Digital audio in digital form, Laserdiscs store Dolby Digital in a frequency modulated form within a track normally used for analog audio. Extracting Dolby Digital from a Laserdisc required a player equipped with a special "AC-3 RF" output and an external demodulator in addition to an AC-3 decoder. The demodulator was necessary to convert the 2.88 MHz modulated AC-3 information on the disc into a 384 kbit/s signal that the decoder could handle. DTS audio, when available on a disc, replaced the digital audio tracks; hearing DTS sound required only an S/PDIF compliant digital connection to a DTS decoder."

Most receivers cannot handle an AC-3 RF signal, therefore you need the RF de-modulator to make it a compliant 384 kbit/s signal.

An example of an AC-3 RF Demodulator from Pioneer with it's inputs and outputs can be found here:
http://home.q03.itscom.net/nsa/PioneerRFD-1.htm

The AC-3 RF output from the Laserdisc player would go into the AC-3 RF Demodulator, which converts the signal and outputs it as digital coax that can be used with a regular receiver and sound card

I read at various places that the Creative cards by default aren't "bit accurate" and therefore cannot save AC-3 streams properly? Do you need special drivers for this?

[edDV]

This seems like very early experiments. I don't recall RF.

What is your Laserdisc player model?

My remaining Laserdisc player is a Sony MDP-333 with a normal S/PDIF optical connection that communicates normally with A/V receivers.

[Herrie1982]

This seems like very early experiments. I don't recall RF.

What is your Laserdisc player model?

My remaining Laserdisc player is a Sony MDP-333 with a normal S/PDIF optical connection that communicates normally with A/V receivers.

I got a Sony MDP-533 (European model of your MDP-333) with exactly the same looks/specs for the rest I guess:
http://www.laserdiscarchive.co.uk/laserdisc_archive/sony/sony_mdp-333/sony_mdp-333.htm
http://www.laserdiscarchive.co.uk/laserdisc_archive/sony/sony_mdp-533d/sony_mdp-533d.htm

The S/PDIF optical connection on the player can only be used for the PCM and DTS signal but it won't output AC-3 for you The manufacturers decided not to include the RF demodulator in the players because it would make them too expensive

For AC-3 you need to have an AC-3 output, which has only been added to most consumer players in US/Europe from 1993 onwards. Most older players can be modded so it can output an RF AC-3 signal. (http://www.laaudiofile.com/ac3mod.html)

I also have a Pioneer CLD-2950 which is acclaimed to be the best PAL/NTSC player image quality wise, however it's from 1992 so doesn't have AC-3 output by default but it has been modified so now it has

[Nelson37]

The X-fi cards are 24-bit, bit-accurate cards. I have captured dozens of valid ac-3 streams thru both optical and coaxial inputs, from both satellite and OTA signals. You must specify 24-bit capture in the Creative software, have not found any other softwares which will capture correctly. The file requires some post-processing thru either VLC or BeSweet. Very fast and simple.

Have never heard of this being done from laserdisk thru an RF modulator, but this source is far less common. As long as the output is AC-3 intended for a decoder and not PCM, it should work. You can capture PCM this way, but SFAIK this is not 5.1.

I have only read of one or two other cards which can do this, and the reports were not extensive. The Mac Mini is also apparently capable of doing this capture.

[Herrie1982]

The X-fi cards are 24-bit, bit-accurate cards. I have captured dozens of valid ac-3 streams thru both optical and coaxial inputs, from both satellite and OTA signals. You must specify 24-bit capture in the Creative software, have not found any other softwares which will capture correctly. The file requires some post-processing thru either VLC or BeSweet. Very fast and simple.

Have never heard of this being done from laserdisk thru an RF modulator, but this source is far less common. As long as the
output is AC-3 intended for a decoder and not PCM, it should work. You can capture PCM this way, but SFAIK this is not 5.1.

Thanks

The AC-3 output from the RF demodulator is intended for a decoder

The optical output from a Laserdisc player itself will only output PCM Stereo and DTS, so yes you cannot capture 5.1 this way.

I have only read of one or two other cards which can do this, and the reports were not extensive. The Mac Mini is also apparently capable of doing this capture.

I will probably give the Asus a go. It seems to be a very nice card and people seem to be happy with it. With it's price around EUR 100,- new it seems to be a quite good option I'll post my results here once I receive the card

[Nelson37]

Don't forget to turn your speaker or headphone volume WAY down when testing or monitoring the captured file. The initial captured file is VERY loud and pulsating and could cause damage.

[Herrie1982]

Thanks for the tip Will do Hope to get the card shortly, maybe on Tuesday