Question about onboard SPDIF / transport to a DAC

just Scott · 25 May 2008 at 17:37

Hey guys

Just a quick question. I've just bought a new DAC, which is going to be the source in my headphones setup. The DAC's only inputs are SPDIF (optical and coaxial). Now, my motherboard has onboard digital outputs of both kinds, but I'm always hearing how bad the quality is from them. So I was wondering, what would be the best way to get around this? I've got about £20 to spend.

Should I get a sound card with digital outputs? For about £20 I could probably get a cheap Soundblaster - the question is, would it output higher quality than my motherboards SPDIF output? Also, if you search the popular auction site for "usb to spdif" there are a couple of adapters from Hong Kong, does anyone know if they'd do a good job or not?

Thanks for any input.

AbsenceJam · 25 May 2008 at 18:52

The digial outputs of your onboard sound will be bit perfect, it's just the analog outputs that will be crap.

just Scott · 25 May 2008 at 19:14

Ah I see. So there's no benefits of a different digital output then?

AbsenceJam · 25 May 2008 at 19:21

That's right, it would be identical. Digital interfaces don't suffer from interference.

just Scott · 25 May 2008 at 19:24

Great, thanks mate you've saved me 20 quid.

dave-lew99 · 25 May 2008 at 20:21

Depends how stable the clock is, ideally you'd get a sound card you can slave to the clock in your DAC

You can get interference on digital signals - it manifests itself as jitter - usually inaudibly.

AbsenceJam · 25 May 2008 at 20:37

dave-lew99 said:
Depends how stable the clock is, ideally you'd get a sound card you can slave to the clock in your DAC

You can get interference on digital signals - it manifests itself as jitter - usually inaudibly.

I specifically avoided mention of jitter, that's for people with too much time on their hands since it is completely inaudible in even the worst of cases.

dave-lew99 · 25 May 2008 at 21:19

AbsenceJam said:
it is completely inaudible in even the worst of cases.

No it's not, it drastically reduces the width of the stereo image and the depth of the sound - you don't hear jitter per se but you can definatly tell the difference with and without it.

just Scott · 25 May 2008 at 22:09

So erm, should I get a sound card or not?

Bare in mind my headphones are pretty transparent and would most likely reveal flaws in a system. I have Sennheiser HD650s.

dave-lew99 · 25 May 2008 at 22:31

If you're going to buy a soundcard, only do it if you can lock the clock on it to that on your DAC, i don't know the make/model of your DAC to be able to tell you if it has that feature.

It's not going to be cheap, so use the onboard for now and see what you think.

just Scott · 25 May 2008 at 22:42

dave-lew99 said:
If you're going to buy a soundcard, only do it if you can lock the clock on it to that on your DAC, i don't know the make/model of your DAC to be able to tell you if it has that feature.

It's not going to be cheap, so use the onboard for now and see what you think.

Not sure what you mean by that.

This is the DAC I have.

AbsenceJam · 26 May 2008 at 08:34

dave-lew99 said:
No it's not, it drastically reduces the width of the stereo image and the depth of the sound - you don't hear jitter per se but you can definatly tell the difference with and without it.

"width of the stereo image and depth of the sound" - don't throw around silly phrases from a stereophiles magazine, its affect on the waveform is not that. I've yet to see a double blind or any other test where the affects have been audible unless artifically introduced.

H2F Scott said:
So erm, should I get a sound card or not?

Bare in mind my headphones are pretty transparent and would most likely reveal flaws in a system. I have Sennheiser HD650s.

Ignore it, trust me, it's very much along the lines of thousands on speaker cable and power leads. I own HD650's myself.

dave-lew99 · 26 May 2008 at 11:24

Obviously you don't have a clue what you're talking about if you think i get phrases from audiophile magazines - i have sat and i have heard the difference it makes myself, i can also hear the difference on small capacitor change on a tweeter crossover makes - that was some testing i did for a research company.

That DAC doesn't appear to support external clock anyway, i was assuming since it was a standalone DAC it would be somthing more fully featured, that's just a digital headphone amp to me.

just Scott · 26 May 2008 at 11:48

dave-lew99 said:
Obviously you don't have a clue what you're talking about if you think i get phrases from audiophile magazines - i have sat and i have heard the difference it makes myself, i can also hear the difference on small capacitor change on a tweeter crossover makes - that was some testing i did for a research company.

That DAC doesn't appear to support external clock anyway, i was assuming since it was a standalone DAC it would be somthing more fully featured, that's just a digital headphone amp to me.

It's only a £60 DAC. It has a headphone amp and pre-amp built in as well yeah. I won't be using them though, I have a separate headphone amp.

Apparently it's the best DAC in the price range though.

AbsenceJam · 26 May 2008 at 12:08

dave-lew99 said:
Obviously you don't have a clue what you're talking about if you think i get phrases from audiophile magazines - i have sat and i have heard the difference it makes myself, i can also hear the difference on small capacitor change on a tweeter crossover makes - that was some testing i did for a research company.

That DAC doesn't appear to support external clock anyway, i was assuming since it was a standalone DAC it would be somthing more fully featured, that's just a digital headphone amp to me.

I presume all this was done double blind, and can you upload the results of your testing?

dave-lew99 · 26 May 2008 at 12:50

AbsenceJam said:
can you upload the results of your testing?

No, it's commercially sensitive and it was done in the lab.

On a £60 DAC you won't be able to tell, i was assuming the OP was spending upwards of £1,000 as thats generally where standalone DACs start being worth it, this is nothing more than a digital headphone amp.

AbsenceJam · 26 May 2008 at 13:03

Standalone DACs only start to be worth it when they cost £1000+?
Jesus... :rolleyes:

My last post on the subject.

just Scott · 26 May 2008 at 13:54

dave-lew99 said:
No, it's commercially sensitive and it was done in the lab.

On a £60 DAC you won't be able to tell, i was assuming the OP was spending upwards of £1,000 as thats generally where standalone DACs start being worth it, this is nothing more than a digital headphone amp.

It's a DAC with a headphone amp. If it was just a "digital headphone amp" then it wouldn't have the feature to bypass the amp and use it as a standalone DAC. Unless I'm missing something...

I think I'm going to take AbsenceJam's advice this time mate. He seems to be a bit more realistic about it.

dave-lew99 · 26 May 2008 at 14:13

Bypassing the headphone amp is very simple, they've just stuck it in as an additional selling point.

Really you'd have been better off getting a soundcard with a higher quality analog output stage and feeding that into your own headphone amp.