bit-perfect output & optical out

[NeoVibe]

Hi

I'm thinking of going seriously into PC-based audio setup, either through USB-DAC or Optical out from soundcard to DAC. Since I already have a soundcard with optical out, a DAC would be nice as I could connect it to my standalone CD Player and my soundcard.

So, I'd like to know how can I tell if my 6 or 7 years old Maxisound Fortissimo soundcard (with Yamaha DS1 chipset) has bit-perfect output through the optical out??
Is it just a matter of looking into the spec sheet?? (I don't have it and can't find it anywhere on the web)

also, being bit-perfect, does the quality of the optical out matter??

As for optical cables I know quality matters, but does it matter as much as it does with interconnects?? how much for a decent optical cable (more or less...)?

I'm aware of the famous Chaintech AV710, but I'd just buy it in case my current card can't output a decent signal to a DAC.

thanks for your help

 

[Solude]

If its listed as a AC97 compliant then no it isn't bit perfect.

The AV710 is the least expensive entry into the hi-fi pc market. A good cheap toslink cable is the AudioGon Glass.

That would be a good budget oriented pc transport rig.

 

[regal]

Just because you buy a AV-710 don't think you will have bit perfect.

The only way to know if you have bitperfect is to hook the digital out to a Hometheater reciever and play a DTS disc or file from your computer. If you hear music then you have bitperfect. If you hear static you don't. Doesn't matter what people tell you or how you setup the card with ASIO, Kernel Streaming, etc. If you hear static, you don't have bit perfect.

 

[NeoVibe]

thanks for the cable recomendation Solude. I can't even tell if it's AC'97... the only thing else I know the chipset reference (yamaha ymf744) but searching google I found no other information.

regal, I don't have a receiver with dts so I can't try that. is the static ou refer to very obvious? if it is I guess it's just a matter of trying... if I get static I'll buy the chaintech, if not I'll keep this one.
but what are the other factors involved to get bit-perfect? what else can get in the way for someone with an AV710 ?

And by the way, is there any point in spending extra money in a card more expensive than the AV710 just to get "a better optical out"?? does this make any sense? or are all optical outs identical?

and finally, a n00b question: does the length of optical cables affect sound quality? Is a 3ft cable 'worst' than a 9ft cable??

thanks

 

[GASTAN]

NeoVibe: I've heard u need to have at least 1.5meter cable to avoid some reflections. I just got van den Hul optocupler mkII (1.5m M-T) for 77EUR shipping and I think it's better than my old cheap one.
I hope so

gotta check that and compare somehow.

 

[K2Grey]

Quote:

Originally Posted by NeoVibe And by the way, is there any point in spending extra money in a card more expensive than the AV710 just to get "a better optical out"?? does this make any sense? or are all optical outs identical? and finally, a n00b question: does the length of optical cables affect sound quality? Is a 3ft cable 'worst' than a 9ft cable??

Bit-perfect just means that there is no difference in information between the original digital file and what is coming out of the digital out.

There should be no difference between optical outs. The extra money of a more expensive card, is likely going to things unrelated to the optical out. However, people have claimed to hear significant sound quality differences between different optical outs. Of course, people have claimed to hear significant sound quality differences between practically everything, so you must take that into account.

A 9 foot cable is worse than a 3 foot cable, but not likely enough to matter.

 

[NeoVibe]

Quote:

Originally Posted by K2Grey Of course, people have claimed to hear significant sound quality differences between practically everything, so you must take that into account.

Tell me about it... I think that's the main reason why people who join head-fi also seem to join imeadiately Team "I've-got-no-more-money-after-upgrading-every-component-in-my-system.............twice!"

It's a good thing I've just finished college

meanwhile I've been reading an article recomended somewhere in this forum (from http://www.positive-feedback.com/Issue14/spdif.htm) that also states that a digital cable too short is more prone to reflections inducing jitter, but beyond a certain size it certainly won't do anything good for the signal. The ideal for me would be a 9ft optical cable so I guess that's OK... anyway, no one would want a computer too close to their precious dedicated DAC...

Now all I have to do is choose a DAC... I get the feeling it won't be easy...

 

[nichifanlema]

Quote:

Originally Posted by NeoVibe meanwhile I've been reading an article recomended somewhere in this forum (from http://www.positive-feedback.com/Issue14/spdif.htm) that also states that a digital cable too short is more prone to reflections inducing jitter, but beyond a certain size it certainly won't do anything good for the signal. The ideal for me would be a 9ft optical cable so I guess that's OK... anyway, no one would want a computer too close to their precious dedicated DAC...

Yeah well but all the article talks about is SPDIF cables....and those are Coaxial, not Optical!

 

[NeoVibe]

yes, you're right, I mixed things up because I was also reading this one http://www.positive-feedback.com/Issue22/nugent.htm that talks about coaxial and optical (besides USB...) and I assumed that it was valid for both. So I guess a 9ft cable should be coaxial instead of optical...

but then again... let's sum it up:

- the performance loss between 3ft and 9ft is "likely not enough to matter" (as K2Grey said);
- having the PC away from the DAC is good because it reduces possible electrical/magnetical interference (and it's very practical...);
- an optical out from a PC will 'isolate' the rest of the system from the 'dirty current' from the PC unlike a coaxial out.
- the optical out has more jitter because of the electrical-optical-electrical convertion.

if these arguments are correct, supposing that isolating the DAC from the PC in terms of current is more important than the extra jitter associated with an optical out then I'd assume that for PC's the ideal is optical and that for a standalone transport the ideal is coaxial.

Does all this make sense?? it's the conclusion I come to after days of reading through this forum...

obviously, a USB DAC has much less jitter than coaxial or optical so it should be the ideal (that's the point of this article http://www.positive-feedback.com/Issue22/nugent.htm), but the only problem is that it reduces to only a few my possible candidates for a DAC.

by the way, I've never heard anything about the importance of a USB cable's lenght.... is it more or less important than it is for optical/coaxial??

thanks

 

[regal]

Quote:

Originally Posted by K2Grey Bit-perfect just means that there is no difference in information between the original digital file and what is coming out of the digital out. There should be no difference between optical outs. The extra money of a more expensive card, is likely going to things unrelated to the optical out. However, people have claimed to hear significant sound quality differences between different optical outs. Of course, people have claimed to hear significant sound quality differences between practically everything, so you must take that into account.

This is completely untrue. Bitperfect just means the data is the same. The timing or jitter can be much higher on different soundcards with bitperfect data.