KeithEmo
Member of the Trade: Emotiva
- Joined
- Aug 13, 2014
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Sounds like someone is asking for a listening test between a Theta Gen V and a DC-1? Should be a slam dunk for DS, right?
The problem isn't DS resolving too much of the original detail, it's that the reproduction method introduces digital noise. They use filters that are supposed to get rid of that noise but there's debate (obviously) about how effective that is and whether it neuters the microdetails in the sound (plankton). There are many posts in the thread dealing with why on both sides. Anyway the resolution of a 16/44 file isn't going to change no matter what you feed it into, a modem dac will still have the same bits to deal with as the hoariest old battleship. Obviously high-res sound files will be better on DS as the old dac won't decode it, whether that high-res audio on DS is preferable to redbook on multibit vintage is an interesting question.
You said it - but I won't disagree with you there
However, you seem to be under a slight misconception about digital filters. It's not that "the D-S process produces digital noise - which must then be filtered out". All digital files consist of the actual information you want, mixed in with extra "stuff" (the energy content of the "steps" that occur at the sample rate). That extra stuff MUST be removed somehow, which is only right, since you only get back the original signal after it is removed. (Think of it like making an exact copy of a statue out of stone. You rough it out, then you sand it, and finally you polish it. And, in the end, it hopefully ends up being just like the original. The process isn't "bad" because sanding is one of the steps, and the statue looks bad until you sand it.) So, both R2R DACs and D-S DACs, and both NOS and oversampling DACs, end up with a signal which must be processed through a filter to remove the "excess junk" and get back the signal you want. Oversampling basically alters the characteristics of the noise that is present in such a way that it is easier to filter out. (And the "accusation" is that, even though the result is easier to filter out, and so there is less of it left after it's filtered, it's so much nastier than the original that even the tiny amount that survives is more audible than the original noise.)
The real debate, or claim, or what you will, is that the specific types of noise used/produced by the D-S process is either somehow "inherently worse" than other types, or that it's more of a problem because it isn't being properly removed, and so there's more of it left to be heard, or both. I see people deeply concerned that the noise floor on a specific D-S DAC might be modulated, which could be unpleasantly audible... yet they forget that the noise floor they're worrying about is at -125 dB, which is about 30 dB BELOW the noise floor on a CD.
The problem I have with many of these discussions is that they start out with a technical argument, but end up with "I know the problem is present, therefore it MUST sound bad" - which is simply faulty logic. There are many reasons why two DACs might sound different, and whether each happens to be R2R or D-S is just one of them. I would very much like to see someone conduct an actual study to determine if most people can actually hear the difference between R2R DACs and D-S DACs. Unfortunately, in order to do such a test, they would have to eliminate all the OTHER variables, of which there are a lot - many of which can be difficult to eliminate. (You must first find an R2R DAC which can match the noise, frequency response, and distortion performance of the D-S DAC you want to compare it to... which may be a difficult and expensive proposition. Otherwise, we're left wondering if you're simply interpreting the flaws as virtues. An R2R NOS DAC that rolls off the high-frequency response by 2 dB at 20 kHz is going to sound so obviously different because of that roll off that you aren't going to hear any more subtle differences that might be present - nor will you be able to confirm that it IS otherwise identical.)