[Oublie]

Hi,

In the near future i'm upgrading my preamp and dac. Im currently using a cheap external usb sound card as a dac feeding usb to the soundcard then using a 3.5mm stereo to dual phono/rca into the preamp of a NAD 3020b. all other things set aside should i go computer to dac/preamp via usb, optical or digital coax?

I'm not wondering about quality of cables just which connection will give the best performance?

I understand that usb is limited to 48khz, digital coax can have noise issues so would i be right to go with optical?

thanks.

 

[Oublie]

Anyone?

 

[Chri5peed]

I personally use Optical, I've not had a problem yet.

You'll be told of its horrible jitter affliction.

 

[Oublie]

Yeah this jitter thing only seems to have come around about 5 years after the invention of the cd player how come if wasn't there before

so since i've never heard it and dont know what it is i'm probably with you on the optical unless someone can convince me otherwise.

Thanks.

 

[gregorio]

Digital co-ax should not have any noise problems. Even if there is some noise is should not affect the quality of the audio in anyway. Most professionals move digital audio around using the AES/EBU format (not a consumer format), second choice would be coax and last choice is usually optical, as it's more delicate and prone to interference over distance.

Jitter has always been a problem, although less so today than a decade or so ago. Jitter is essentially timing errors in the digital audio chain. Severe jitter causes clicks and pops but lower levels of jitter cause more subtle artefacts. These are usually, narrowing or inaccuracies in the stereo soundfield, loss of some freqs (low mids mainly).

 

[Oublie]

Quote:

Originally Posted by gregorio /img/forum/go_quote.gif Digital co-ax should not have any noise problems. Even if there is some noise is should not affect the quality of the audio in anyway. Most professionals move digital audio around using the AES/EBU format (not a consumer format), second choice would be coax and last choice is usually optical, as it's more delicate and prone to interference over distance. Jitter has always been a problem, although less so today than a decade or so ago. Jitter is essentially timing errors in the digital audio chain. Severe jitter causes clicks and pops but lower levels of jitter cause more subtle artefacts. These are usually, narrowing or inaccuracies in the stereo soundfield, loss of some freqs (low mids mainly).

so in a static home system i should be fine with coax or optical And in order to reduce any possibility of jitter i should use the highest sample rate i can to reduce jitter or will this not make a difference? I'm keen to go with the best type of connection in order to make the most of the available technology that way a great dac will not be hindered by poor connection and a good dac will not suck. I've been looking at dacs but i'm trying to be fairly logical about my upgrade path. As you can see i run stax out of a energizer with a nad 3020b. the dac will either link to the power amp stage of the amp or go through the pre but imo i need a good digital basis to start from i.e. the old adage of garbage in garbage out.

 

[Chri5peed]

Don't know if this is of use to you, but my MicroDAC can use all 3 connections:

So, pretty easy to do a test. USB is a generic lead[USB>Mini-USB], Co-ax[Mini], Optical[Reg or Mini].

 

[gregorio]

Quote:

Originally Posted by Oublie /img/forum/go_quote.gif so in a static home system i should be fine with coax or optical And in order to reduce any possibility of jitter i should use the highest sample rate i can to reduce jitter or will this not make a difference? I'm keen to go with the best type of connection in order to make the most of the available technology that way a great dac will not be hindered by poor connection and a good dac will not suck. I've been looking at dacs but i'm trying to be fairly logical about my upgrade path. As you can see i run stax out of a energizer with a nad 3020b. the dac will either link to the power amp stage of the amp or go through the pre but imo i need a good digital basis to start from i.e. the old adage of garbage in garbage out.

The connection itself has little baring on digital audio. Effectively all that is passing through the cable is a series of zeros and ones. It makes no difference whatsoever the audio quality of these zeros and ones, just so long as the quality is not so bad that they can't be differentiated. This is one of the great advantages of digital audio over analogue, when moving a digital signal around you don't have to worry about the quality.

Higher sample rates have no inherent advantage over lower sample rates when it comes to jitter. You have to bare in mind that jitter is always present to some degree on the recording, from when it was first made. If the jitter was quite serious, re-sampling can give an improvement but as a general rule, up-sampling is likely to cause as many problems as it solves. As a general rule also, the more expensive the converter the better sound quality you will get out of it. Don't get bogged down looking at jitter specs either, there is no standard point at which to measure jitter so a piece of equipment with a very low jitter spec may actually have more jitter than a piece of gear with a higher level of jitter in it's specs!

 

[Chri5peed]

Quote:

Originally Posted by gregorio /img/forum/go_quote.gif The connection itself has little baring on digital audio. Effectively all that is passing through the cable is a series of zeros and ones. It makes no difference whatsoever the audio quality of these zeros and ones, just so long as the quality is not so bad that they can't be differentiated. This is one of the great advantages of digital audio over analogue, when moving a digital signal around you don't have to worry about the quality.

I may have a $130 Optical lead, but I essentially believe this.

Although you'll find many here who'd sell their Grandmother for $5, if this
were true.

 

[Oublie]

So basically guys it won't matter whether i choose to go optical or coax as long as i have i semi decent cable. thanks for all the info some i knew some was new to me. one last question - since the connection is purely digital can i assume i don't have to worry about a fancy ass sound card since i'll be using an external dac?

 

[gregorio]

Yep, you've got it. There is absolutely no need for expensive digital cable, it won't make any difference.

Oublie - That's right, if you are bypassing the DAC circuitry in your soundcard, there doesn't seem much point in splashing out for a high quality soundcard. So long as your soundcard is reasonable enough quality to output digital audio accurately that is.

 

[Chri5peed]

Yep, essentially an external Amp/DAC is doing what a soundcard would do.

You're essentially ejecting audio files from your computer as they are stored on your HDD[use ASIO/Kernel-streaming].

I've a Juli@ soundcard from prior listening.