[Aimless1]

I recall reading a review of the bel canto dac.3 where one reviewer stated that the sound stage was narrower and the bass rolled off when the computer was used as the source as opposed to a cdp. I just read a review of a blue circle dac where the author said the same thing. Didn't pull the bel canto review, but perhaps it was the same author.

Then reading about the red wine audio product line I see he recommends using the computer as the source as well the wavelength audio site with the cosecant.

I'm wondering if this is a real or ficticious difference? Or perhaps a NOS DAC behaves differently with a computer as source?

discussion...

 

[Mr_Sukebe]

Computer audio has definite pros and cons. The key pros being the convenience of having all your music collection accessible very quickly. The bad news is that PCs themselves tend to have not the most clever implementation of SPDIF outputs, meaning that they have higher jitter than some other sources (e.g. dedicated CD transports).

 

[mackman]

The asynchronous upsampling chip in a lot of the higher quality DACs reclock the signal eliminating jitter. A non-upsampling DAC may not do this and you will be subject to the sometimes substantial jitter of your PCs digital output.

 

[Jon L]

Quote:

Originally Posted by Mr_Sukebe /img/forum/go_quote.gif The bad news is that PCs themselves tend to have not the most clever implementation of SPDIF outputs, meaning that they have higher jitter than some other sources (e.g. dedicated CD transports).

The reviews OP refers to are talking about the USB inputs of these DAC's in questions, which are implemented suboptimally in these specific cases. Yes, they sound much worse than good spidf input.

On the other hand, PC's can have excellent spdif outputs. You just need to forget those motherboards have spdif outputs and use a *real* spdif output card with transformer-coupling either at the card or DAC, or both.

As far upsampling/oversampling/NOS DAC's with PC, it does not matter. A great-sounding DAC, no matter the topology, will sound great via transports *and* PC, and vice versa. That's my experience.

 

[donunus]

Theres some confusion here. Aimless1, upsampling and non upsampling is different from oversampling and non oversampling. NOS is non oversampling

 

[Aimless1]

You're absolutely right, of course. I'm referrring to OS (over sampling) vs NOS (non oversampling). I just changed the title to reflect this.

Perhaps to clarify...I've read many reviews that say there is a drop off in SQ on OS DACs when switching from a traditional source like a CDP to a computer. The computer connection used may or may not be USB. This does not seem to be the case with NOS DACs. Vinny (Redwine Audio) and Gordon Rankin(Wavelength Audio) seem to prefer the computer as source using a USB connection.

This is relevant for me as I think about upgrading my system. I have committed to the MacBook as source/transport. In fact, my CDP is only connected to my stereo system, not to my head amp. The problem is separating bias from fact when reading the reviews.

I am beginning to believe that NOS DACs in general are better with computers as the source. But logically I'm having a hard time accepting this. Can this really be the case?

 

[StanleyB1]

Quote:

Originally Posted by Aimless1 /img/forum/go_quote.gif I've read many reviews that say there is a drop off in SQ on OS DACs when switching from a traditional source like a CDP to a computer. The computer connection used may or may not be USB.

I have found that USB has a drop off with the equipment I have heard so far, but not optical or coax. Look for a DAC that reclocks. They tend to handle PC and CDP just as well.

 

[donunus]

heres a thread where a guy talks about his usual findings of the differences between OS and NOS dacs

Four DACs - Thumbnail Sketch

he says "In my experience, NOS DACs can have weaknesses in: dynamic contrast, frequency extension, instrumental separation, focus, and resolution.

Normal NOS strengths: Singularity of voice, lyrical flow, un-digital presentation"

 

[donunus]

oh but then again, you also have to think about the way the dac interfaces with the usb... Thats probably a big part in its USB performance. Most dacs sound better using SPDIF vs USB whereas some are designed to sound great out of the USB like the benchmark dac1... but then again, the benchmark might not be as good as a nos dac in the same pricerange though unless you will primarily use usb

 

[Aimless1]

Thanks for the link. Interesting observations for a traditional source played through a speaker system. Obviously the ECD-1 and Lessloss DACs are top end gear. But you have to wonder if those results
1. translate to computer as source
2. apply to headphones
I would have to agree that in a traditional set up the Spdif would be the preferred interconnect...and that it is DAC/system dependent as to whether it or a usb connection is better with computer as source.

I believe that both OS and NOS DACs do their job well, albeit differently. But, does one perform better with usb and/or computers than the other one? That's a ridiculous question as it depends on many factors including the rest of the system, not to mention one OS DAC may be better or worse than another NOS DAC. But in general does one type perform better in a system with the computer as source/transport? Or am I making mountains of mole hills, or worse, on a wild goose chase with no real answer available?

 

[donunus]

Probably no real answer since different nos dacs don't sound the same and different systems will tend to need certain aspects of the dacs sound more than others. I guess the closest answer to your question can be answered with his observations of typical nos dacs having those characteristics and whether you like those typical characteristics or not.

 

[Aimless1]

This is an interesting article comparing NOS to OS kusunoki

In part it says" The difference between the non-oversampling DAC and the conventional DAC with the digital filter lies whether you attach importance on the accuracy in the time domain or in the frequency domain. In other words, whether you choose the musical performance or the quality of a sound. This trade-off line defines the boundary of the current digital audio format .
A natural, stress-free sound that communicates the musicians' intention directly to you. That is the sound of non-oversampling DAC. The feel of this sound is closer to that of analog reproduction."

The old do you listen to the notes or to the music discussion.

Anyway, the answer apparently is there is no answer, or rather no difference other than in individual DACs.

 

[donunus]

wow, nice article. I cant understand all of it but a great read nonetheless.

 

[pepsi123]

Quote:

Theres some confusion here. Aimless1, upsampling and non upsampling is different from oversampling and non oversampling. NOS is non oversampling

hi I'm new to this forum, so hi! just wondering what the difference is between upsampling and oversampling? is one to do with sync clock and the other to do with audio sample rate. just trying to get my head around DACs and being confused about the terms is not helping! any advice would be much appreciated. many thanks, matthew horton.

 

[dyl1dyl]

Both upsampling and non-upsampling Dacs can have great sound but if you want the purest sound, get non-upsampling