Over Sampling vs Non Over Sampling DAC w/computer as source

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...

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?

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?

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.