On-board ALC889 SPDIF input won't accept 32kHz audio signal

[tbob]

OK, I'm probably the only one in the world with this problem, but I didn't know where else to ask the question, so here goes:

I built a computer for video and audio work with a Gigabyte GA-EP45-DQ6 (rev. 1.0) motherboard. The onboard audio (Realtek ALC889) is actually pretty decent, and I was impressed to see a coaxial SPDIF output built right into the motherboard. So I looked around and found that, sure enough, there's a SPDIF-input header on the board, and you can even get a panel-mounted SPDIF-IN module, which I did. Gigabyte calls it by this part number: 12CR1-1SPDIN-01R

I work with a lot of DAT tapes. Some are recorded at 48kHz, some at 44.1kHz, and some at 32kHz, all 16-bit. I'm trying to transfer this audio to the computer for editing, and SPDIF IN works perfectly for this.

The problem is, the computer receives the 48kHz input just fine, but the 32kHz digital signal just comes out all garbled. Sounds to me like a clock problem, maybe?

The Realtek driver isn't very straightforward (there are limited digital options, and NO SPDIF-IN options), so I'm guessing that's where the problem is, not the hardware. The realtek ALC889 datasheet even mentions the ability to receive 32kHz input.

Does anyone have any guesses as to how to fix something like this? ... or where I should go to fix it?

Thanks for any help!

 

[tcsenter]

Its probably a Realtek driver bug. Give Realtek a try:

Tech Support for Audio CODECs & Sound ICs

Tel: +886-3-578-0211 (Ext: 3758)
Fax: +886-3-577-4713
Email: pctech@realtek.com

 

[tbob]

Ha! Actually had a tech support email in to Realtek, and they responded last night... said that it was Dolby-designed, and that it only handles 48kHz input.

So... let me get this straight: Realtek builds the chip, Dolby builds the 5.1 and digital stuff using the Realtek chip, Realtek writes the driver... and Realtek can't control the input clock frequency?

Oh, well.

 

[tcsenter]

Hmm, that's strange. Oh well, at least you're working with a digital source, the 0's and 1's are always the same.

Edit: I created a new post for the rest...

 

[tcsenter]

After looking around, it seems there are no cheap PCI sound cards that do 32MHz input, only more expensive prosumer and professional segment sound cards. However, I did run across these external USB interfaces:

PPA 1455 6 Channel External USB Sound & VoIP Interface

Features for Digital Recording Mode:
[*]Receives SPDIF digital audio input and sends back to PC through USB.
[*]Three sampling rates; includes 32KHz, 44.1KHz and 48KHz; are automatically locked internally.

ADS Tech Instant Music External USB Interface

Supported sampling rates: 8, 11, 16, 22, 32, 44.1, 48 kHz


Looks promising, no? Alternatively, since you are into DAT, maybe someone you know has a professional sound card or audio interface you could borrow, like M-Audio Delta 66, 1010, 2496, and so on.

One last note, have you tried using a different recording application? I've seen some notes that suggest a bug or glitch in the application can screw this up, too.

 

[ElBurro]

Originally posted by: tcsenter
Hmm, that's strange. Oh well, at least you're working with a digital source, the 0's and 1's are always the same.

Edit: I created a new post for the rest...

except for when they are not. There is a reason ECC exists.

 

[tcsenter]

Originally posted by: ElBurro
except for when they are not. There is a reason ECC exists.

ECC isn't used for SPDIF, so your statement is about as relevant as cheese making.

 

[nenforcer]

Correct me if I'm wrong, but is 32KHz even a part of the Dolby Digital spec? I'm pretty sure everything from the CD era (early 80's) has been 44.1 or higher and so obviously only dealing with something like DAT tapes is going to run into this issue.

I would imagine there is no reason why it can't support 32KHz its just probably not there.

 

[tbob]

I ended up getting an external USB interface (Edirol UA1D), which seems to work ok, but mayhaps is dropping a few samples every so often. I haven't had time to look into it in detail, but that's my feeling. Works fine for capturing small clips from the tape, though.

 

[jalyst]

@imported_Thob, apologies for the necropost!

Any idea whether it'd be possible to use the S/PDIF-in to capture DD/DTS from an Xbox360/PS3, decode it, pass it through a HRTF filter like Dolby Headphones, & then convert to stereo analogue?
I was looking at discrete cards, but if I can use the on-board all the better!!

Ideally I'd like to re-route the DAC stage or the encode to DH + DAC stage to my Essence ST.
But that's probably getting too far out of the realm of possibility...

 

[jalyst]

Actually I don't think my motherboard has a S/PDIF-in header, so even if it's possible I wouldn't be able to use my ALC889.
Unless Asus sells after-market add-ons for their mobo's which allows one to add a S/PDIF-in header? (doubt it)

So I'll prolly have to use a discrete card, still....
If you've used your on-board or a discrete card to do DD/DTS capture + decode, or just capture.
Or you think it sounds feasible, I'd love to hear further thoughts.

Thank-you.

 

[joetekubi]

I ended up getting an external USB interface (Edirol UA1D), which seems to work ok, but mayhaps is dropping a few samples every so often. I haven't had time to look into it in detail, but that's my feeling. Works fine for capturing small clips from the tape, though.

I did a large DAT project a few years ago with my MAudio 2496 card.
One of the tapes was 32K sample rate. (Yes, it's "legal", but very rarely used, and not advised) What a PIA!
I had to fiddle with all sorts of things in Audacity and the system,
but finally got it to work.

I"ve heard only good things about the Edirol boxes.

For those who don't know, here are some DAT tape guides:
http://www.audiotools.com/dat.html
http://www.solorb.com/dat-heads/

-joe

 

[jalyst]

anyone?

@imported_Thob, apologies for the necropost!

Any idea whether it'd be possible to use the S/PDIF-in to capture DD/DTS from an Xbox360/PS3, decode it, pass it through a HRTF filter like Dolby Headphones, & then convert to stereo analogue?
I was looking at discrete cards, but if I can use the on-board all the better!!

Ideally I'd like to re-route the DAC stage or the encode to DH + DAC stage to my Essence ST.
But that's probably getting too far out of the realm of possibility...

 

[jalyst]

anyone? thank-you.

Actually I don't think my motherboard has a S/PDIF-in header, so even if it's possible I wouldn't be able to use my ALC889.
Unless Asus sells after-market add-ons for their mobo's which allows one to add a S/PDIF-in header? (doubt it)

So I'll prolly have to use a discrete card, still....
If you've used your on-board or a discrete card to do DD/DTS capture + decode, or just capture.
Or you think it sounds feasible, I'd love to hear further thoughts.

Thank-you.

 

[Fox5]

Did you ever try updating the drivers on the realtek device? Grab them straight from the realtek site.

 

[jalyst]

@Fox5
Any thoughts/ideas RE my posts #13 & #14?
Thank-you.