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DACs and reproduced sound

I am trying to understand how to think of DACs effecting reproduced music (I am new to the hobby). I think of a DACs "role" as taking a digital input (1s and 0s) and a cleanly as possible processing that digital signal to an analogue output - goal is not impart anything on the processed data. The difference between a good and bad DAC seems like it should be on how well it does that. Or, said another way, from a review of a Benchmark DAC:

"The old regulars know exactly my position regarding the stupidity of ascribing a “character” to the sound of an utterly neutral signal path. Oohing and aahing over the vast improvement in soundstaging, front-to-back depth, bass delineation, or treble sweetness obtainable with this or that electronic component may sell high-end magazines but is totally unscientific and delusional. What the Benchmark DAC1 HDR adds to or subtracts from its input signal is borderline unmeasurable, so the sonic character of its output is obviously the sonic character of its input. It’s as simple as that. It has no sound of its own."

I sort of think of amplifiers and speakers (I am digital only listener)as being more important in "imparting" a particular musical flavor (warm, bright, etc.).

I am a bit new to the hobby so I would like any insights or be educated on DACs some more.
dangelod
dgarretson
2,394 posts
 
In simple terms, a DAC's analog section is no more or less compromised than any preamp or amplifier circuitry, except for the presence of high-frequency analog filters. In contrast, the adverse signature of the digital domain and digital/analog converter sections, results from jitter, compromises in digital filtering, and characteristics inherent in the DAC chipset. If your DAC has treble glare, hard or flat treble and upper midrange, has a smeary non-resolving quality, sounds synthetic, or becomes fatiguing, you are most likely hearing weaknesses in the digital section and digital/analog conversion. To say that "the sonic character of its output is obviously the sonic character of its input" is just Benchmark marketspeak.

Finally, there are the inherent limitations of the RBCD medium itself. Sadly much RBCD mastering is done poorly and is over-compressed, leading to some of the above symptoms regardless of playback equipment. However, with the right front end, much RBCD can approach SACD and vinyl.

Fortune cookie say that until you get right with CDP or have a good vinyl front end to compare to your CDP, you will experience much restlessness and waste of time & money swapping downstream components.
mapman's avatar
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mapman
15,679 posts
 
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.
dangelod OP
40 posts
 
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 ?
mapman's avatar
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mapman
15,679 posts
 
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.
kijanki's avatar
kijanki
3,575 posts
 
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.
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