Up-sampling VS. NOS DAC's

[the_eleven]

Why would I choose one over the other?

 

Is it more difficult to design a decent NOS DAC?

 

[The Computer Audiophile]

One is not inherently better than the other. There are trade offs with and without oversampling. You just have to let your ears be the judge of how well each DAC is implemented.

 

[rockrabbit]

I just got the Bryston BDA-1 DAC... it has a feature where you can turn on or off the up-sampling.

 

um... LOVE the up-sampling on this DAC!

 

Truth be told, some DAC's when up-sampling is used tend to sound... well... harsh, brittle maybe a tad hard.

 

Now consider my Musical Fidelity X-DAC... had serious up-sampling that when placed on some systems would rip your ears off.... now on my system, which is all tube's it sounded wonderfully detailed with no harshness.

 

Bottom line in my opinion is that you need to try the DAC in YOUR SYSTEM to know the answer.

 

Your mileage may vary!

 

[the_eleven]

So with an all-tube setup (ARC SP-8, VTL monoblocks) something like the Benchmark might not sound too "brittle & dry"?

 

Could someone give me an example of a system where a NOS DAC would sound best?

 

[The Computer Audiophile]

There is no signature to NOS DACs so it is impossible to provide you an actionable recommendation. I'd love to be able to say DAC xyz will work great and DAC abc will not work in your system, but that would be a disservice. Since you are a fan of ARC and VTL I do recommend that you give the new ARC DAC7 a listen. No guarantees, but I have heard great things about it.

 

[cs]

Re: "Is it more difficult to design a decent NOS DAC?"

 

To some extent, yes.

Without any oversampling (ie. keeping the sample rate at 44.1kHz), the design of the analogue reconstruction filters becomes quite difficult. Some NOS DACs dodge the issue by leaving out the filter completely, and relying on your ears to do the filtering ! I don't really agree with this approach.

 

If you use a Sigma-Delta type DAC, they all contain digital oversampling filters internally. These increase the sample rate by an integer factor (usually a power of 2), and make the analogue filtering much easier.

 

The current fad for upsampling is based on the use of sample rate converter (SRC) chips, which can increase the sample rate by a non-integer factor. It is easy to show through both simulation and measurement, that this has no benefit compared to integer oversampling. However, SRC chips also contain digital PLLs, which reduce jitter, and it is this which can result in improved performance compared to NOS DACs.

 

Chris.

 

[iansen]

Am I right in thinking that Upsampling is "Lossy" and not "Lossless"?