Crackling when playing 192khz FLAC files

[redwing]

The little DAC seems absolutely fine with 192khz files bitstreamed from the Oppo player, using the same optical cable as with the PC.

What happens if you use PCM output mode instead of bitstream (raw) with maximum 192kHz?

[hiccup]

Correct, the Oppo is a player. DVD not Blu, 980h. But as far as I can tell it’s set to not down sample anything - digital output is set to “raw”, which is the closest menu option I can find.

You were assuming your Oppo is outputting 192/24 over s/pdif, but it probably isn't.

"Due to copy-control restrictions and bandwidth limitation, full resolution audio output from DVD-Audio or SACD playback cannot be sent through the coaxial or optical digital audio output. To listen to DVD-Audio or SACD in full resolution, please use HDMI or analog audio connections."

So that brings you back to square one.
It could be the cable, it could be Windows, it could be (the drivers of) your dac.

[bobbymcm]

Isn't it great that that these days you can find something for 10 pounds that more or less works and sounds good.
That's kinda fun by itself.

If you are content with it's sound quality and have no plans for upgrading it with some 'serious' dac:

Forget about wasting time testing 'hi-res' vs. 16/44.
Forget about wasting time getting a £10 dac to work perfectly in every possible situation and with every type of audio file.

Convert the bloody lot to 16/44 and just enjoy the music. ;-)

You know what, I really think you are right that what I've got for £10 (less than a pizza) is pretty great all in all. I think I will end up archiving any 192khz files I have outside of Musicbee, but also resample them down to 96khz in F2K and get on with enjoying the (great sounding!) WASAPI music...


...but having said that I'm still fascinated to see if I can get these files to work over the optical output. When I have more time I will try various other cables I might have around in drawers and see what happens then...

What happens if you use PCM output mode instead of bitstream (raw) with maximum 192kHz?

An excellent question. I'll try this and let you know, but I suspect that this...

"Due to copy-control restrictions and bandwidth limitation, full resolution audio output from DVD-Audio or SACD playback cannot be sent through the coaxial or optical digital audio output. To listen to DVD-Audio or SACD in full resolution, please use HDMI or analog audio connections."

...is bang on and was the reason why my Oppo test was successful. The Oppo BDP-83 Blu player I have has the same restrictions stated in the manual, so will probably produce the same false-positive test... but I will try it anyway just to see.

I guess my character is that I find it hard to let go of something like this, that makes no difference in the long run but has become kind of a project to see if I can make it work, so I'm going to keep trying a few other things and see if I can manage anything.

Musicbee does seem great though - glad I found it, and WASAPI playback seems much more reliable than F2K (which claims 88.2khz SACD rip files are unsupported...). So all in all I'm happy!

[hiccup]

... F2K (which claims 88.2khz SACD rip files are unsupported...)

Have you tried this plugin?:
https://sourceforge.net/projects/sacddecoder/files/foo_input_sacd/

About optical cables;
Length by itself is not an issue, but the amount of bending, and whether the material is plastic vs. 'glass' can make a difference.

p.s.
A random quote from someone on a pro-audio forum:
"In my experience the cable made all the difference. 2 of my DACs (Chord Qute EX & Schiit Bifrost Multibit) pass 24/192 without issue using a Lifatec Silflex glass fiber cable. Only 24/96 with plastic fiber using the same 2 DACs."

But obviously first check the specs of the optical output for your motherboard/soundcard to see what it should be capable of.

[redwing]

Not necessarily it's about the brand or price of your DAC but probably it's about you're using a generic optical cable which would support up to 24/96kHz in most cases.

When I said that, I didn't mean you should buy an expensive optical cable. That should be overkill and there's no guarantee it would work with your equipment since the quality of the toslink socket also matters to reliably transmit high-res audio signals.

Probably for your purpose of playing 192kHz files from your PC, using a generic coaxial cable would be enough. I know you said you don't have the output but if you have a chance to test it in another machine, try it. Playing DSD or SACD without converting to PCM will require an HDMI cable, though.

[redwing]

p.s.
A random quote from someone on a pro-audio forum:
"In my experience the cable made all the difference. 2 of my DACs (Chord Qute EX & Schiit Bifrost Multibit) pass 24/192 without issue using a Lifatec Silflex glass fiber cable. Only 24/96 with plastic fiber using the same 2 DACs."

But obviously first check the specs of the optical output for your motherboard/soundcard to see what it should be capable of.

I didn't see that part when I was writing my post. If one edits their original post after reading someone else's follow-up post, they should make it clear that's their reaction to that. Otherwise it would make the follow-up poster look repeating what the previous poster already said.

[bobbymcm]

The motherboard is an Asus P8Z68-LX. Can't find any information about the detailed specs of the optical output on the Asus website, including in the downloadable manual, anywhere.

The fact that the sound is getting through but is really crackly suggests to me that the DAC is capable of decoding the signals but that the cable and/or the mainboard isn't able to deliver those signals quickly enough for 192khz. I have just stumped up for a thicker, shorter optical cable to see if that makes any difference, but I don't know any way I can really interrogate the capabilities of the optical transmitter I have in any great depth.

The only coaxial outputs I have are on the two Oppo players and I don't trust those to be a reliable test as the coaxial input is included in the Oppo disclaimer about bandwith limitations.

Hmmm.....

[hiccup]

Maybe you can find a reseller of a 'glass' optical cable that allows you to return it if it doesn't solve your issue?

But looking at prices, there is a lot of b.s. going on with optical cables.
I found a few with gold plated connectors.
Really. Gold plated connectors for an optical cable.

And for the prices of those you will probably be better off finding a reasonably priced modern usb-dac.

(which would then probably also allow for playing sacd/bit-stream files, in case you are interested in those)

[frankz]

The motherboard is an Asus P8Z68-LX. Can't find any information about the detailed specs of the optical output on the Asus website, including in the downloadable manual, anywhere.

I had a P8Z68-V LX and still have the PDF manual.  Here's what's in the Chapter 1 Product Information section of that manual for reference.

[hiccup]

Here's what's in the Chapter 1 Product Information section of that manual for reference.

Good find. That seems to imply there would be no obstacles with the motherboard then.
(unless the marketing boys and girls 'forgot' to add the fine-print: '192/24 available for analogue connections only')

;-)

[redwing]

The only coaxial outputs I have are on the two Oppo players and I don't trust those to be a reliable test as the coaxial input is included in the Oppo disclaimer about bandwith limitations.

Why not try with 192kHz FLAC files to see what happens? The disclaimer is also about copyright restrictions and it's not clearly stating specific supported bandwidth for each type of cable.

[bobbymcm]

SOLVED!! [EDIT: not solved at all...]

Installed ASIO4ALL and tried that instead of WASAPI... and my 192k files are working! Hooray!

This means I can now get on with not noticing any difference at all, but not worrying that something isn't working as it should.

Happy!  

PS Thanks everyone who helped out. This is a friendly place.

EDIT:

Turns out that ASIO4ALL hadn't picked up the optical output, so was just sending audio through the speakers (which I have set as being 'listened to' via stereo mix for things like YouTube). So I wasn't hearing bitstreamed 192khz after all...

Oh well, back to square one...

I was right about this being a friendly place though!

[hiccup]

Damn, I was happy for you.
And also a bit surprised that asio seemed to work, and a bit embarrassed how you seemed to have been send on a goose-hunt.

But now back to square one, the suggestions of possible causes from captain_paranoia and me might be accurate and useful after all...

Another thought I had (but that won't help you much):

It seems your dac manufacturer advertises the 24/196 feature heavily.
And it looks like they included an optical cable?
Usually you would then expect that that cable would fit the 24/196 feature of the dac, so it should be good enough.

But then again, a 'no-name' brand, 10 bucks, hmmm.

[bobbymcm]

Thanks Hiccup. I was pleased too. For a moment...

You are correct - the 192khz thing is all over the DAC and they did supply their own cable, which I’m using. This leads me to believe it’s my sound output that’s the problem. Also the fact that I hear something of the music means the dac is decoding it, so I wonder if the crackling is because the data isn’t being delivered fast enough. So either cable or drivers are the thing.

Or maybe it’s a £10 Chinese DAC and it would be fine with a coax cable, which I can’t test. So I’ll try my alternative cable when it arrives and see, and if it doesn’t work then it might be time to give up and enjoy what is excellent sound and stop worrying about it!

[bobbymcm]

SUCCESS!!  

The alternative cable I bought (this one, nothing up market), which is half the length and more than twice the thickness of the one that shipped with the DAC, works perfectly, and everything sent to the DAC is decoded and plays perfectly. Crackling with 192khz files is GONE.

Hooray!!