DACs and reproduced sound

Yes, the job of the DAC is to take the 1's and 0's which are the digital building blocks needed to construct an analog waveform and construct it.

Its like building with Legos. The bits (1s and 0s) are the lego blocks. The DAC is the device that takes the blocks and does the construction (of the analog waveform needed by the amp and other components downstream).

No two DACs are exactly the same, so each will sound different, some a lot different and some not so much, but different nonetheless.

The waveform building process requires a clock to tell the DAC when the time is right to use the next set of bits/blocks available to construct the next portion of the sound wave. The clock is often provided upstream from the DAC, either by the transport or some other device that can provide the clock. Sometimes, like with upsampling DACS, like the BEnchmark, I believe, the clock needed is on board with the DAC, so the "DAC" box has everything it needs to build a waveform. REgardless, the clock + the bits/blocks plus the DAC, which determines the analog equivalent of each set of bits presented to construct the waveform, are the basics things you need to convert digital signals to analog ones.

Mapman - very good description and very helpful.

With the clock, if I have a realtively low end CDP or a sonos music streamer, each with their own internal DAC (and, therefore clocks) and I run them through the benchmark, does the benchmark "re-clock" the "onced clocked" signal, making it more accurate ?

Dangelod,

I believe that is true in the case of the Benchmark, but is not always the case in that not all DACs reclock data.

Assuming a low end player relative to the BEnchmark, or also perhaps even just a poor connection from the digital source to DAC, the BEnchmark reclocking should result in lower jitter (errors in the timing) and better accuracy and detail.

Dangelod - jitter is just only one of the elements and it is much more complicated than that. Benchmark asynchronously upsamples incoming digital data about million times to filter it in digital filter and output to 24-bit DAC at 100kHz rate. Filtering itself affects the sound and some prefer no oversampling and filtering at all (NOS DACs). Recently reviewed in Stereophile magazine Meridian CDP uses different filtering scheme and sounds much better (but costs $16k). DAC IC itself comes in different varietes to overcome resolution limitations. Benchmark is using Analog Devices Sigma-Delta DAC (similar scheme to SACD) that has 24 bit resolution (not obtainable in traditional DACs) but timing errors limit resolution anyway. Others use traditional DACs - some with statistical averaging (like DCS RingDACs) to improve resolution. Harmonic distortion play also important part. Benchmark updates DAC ,capable of 192kHz,at only 100kHz because harmonic distortions are much lower at this point. Important to remember is that there is no perfect DAC and everything is a compromise (and very complicated). Listening test will give you much more than reading spects.

I agree that high-end magazines are delusional and unscientific. Nowdays it's very commercial rather than acheiving something scientific.
DAC despite processing 1's or 0's is a complexed logical device (especially today's advanced ones).
Our todays' CD digital format has 16-bit on 'vertical Y axis' and 44.1kHz samplig freequency on 'horizontal X axis'.
Giving example of the highest range of audiable freequencies such as 20kHz will roughly have only 2...3 digital samples * 16bit will yield 36bits of overall resolution.

First DACs processed one bit at a time. The advantage of these DACs is simplicity of the design and logic. The disadvantage is high probability of error meaning to give instead of 5-bits amplitude 3 or 7 bits amplitude since the 'receiving one-bit register' only cares about signal presence or absence i.e. '0' or '1'. Hence the quality of a digital equipment was 90% depended on the analog process which is filtering and buffering garbage.

Nowdays DACs are much more advanced they process sample by sample which may contain upto 24 bits amplitude and upto 192kHz sampling freequency. The proccessing by 'word' or taking the whole sample onto the register allows to logically analyze 'condition' of a particular word hence reducing drastically the probability of error. The DAC ICs are just like jewelry can be dirt cheap and can be pricey depending on what capability they all have and certainly newer and advanced models (such as Benchmark's relocking) would run at the higher price tag but soon will be reduced as the time passes by just like with PCs.

The listening difference vs. old processors is substantial especially on higher freequency details and also dynamics. Less listening fatigue and more natural sound.

The corresponding price of a digital equipment is another point of convincing price paid vs. performance, but often it's not true and not scientifically proven where I agree with poster since the fully functional digital unit that supposingly has the best DAC IC(s) and all possible functions, read all possible high resolution formats can't be priced $10k. Hence I don't think that there's something possibly more advanced and perfect than Grace Design M902 DAC-Preamp-Headphone amp.