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STUPID QUESTION BUT What does a DAC do???

post #1 of 27
Thread Starter 

What does a DAC do. Doesn't is make you music sound better through iTunes. But how does it work if you have you headphones in your headphone amp, what is there a cable that goes from your DAC to your headphone amp????

post #2 of 27

A DAC (Digital to Analogue Converter) does exactly what the name suggests; turns the digital bits from a digital source material (hard drive/CD/other medium) and converts that information into an analogue electronic signal that our speakers/headphones can use to produce sound. The chain is:

 

Transport --> DAC --> Amplifier --> Headphones/speakers

 

A higher quality DAC will do a better job of converting those digital bits into the signal, with a more accurate reproduction of the original sound.

post #3 of 27

A DAC is a (DIGITAL TO ANALOG CONVERTER),so any piece of equipment that reads a disc must  have a DAC ether built in or use an external DAC to convert the digital signal into an analog signal........I'm sure you'll get all the details about DACs in your post,  I myself try to stick to the information that is "IN THE GROOVES" of my vinyl.....Sorry for basically repeating your words,logwed on DACs but,  I had to reboot the page to reply, new sight is still SLOOOOOWER to "ACT" then before.......


Edited by 9pintube - 6/19/10 at 10:38pm
post #4 of 27

a DAC is a tone-generator of the 'reading' type.. while a synthesizer is also a compiler of the 'mouth wide open' or 'input' type.

 

basically a DAC is like a grand piano.

picture the information sent in a binary format.

each 0 and 1 off of the page of data = a tone

 

and that means each page can have more than one piano key pressed at the same time which makes a different tone when compared to a single key of the piano being pressed.

 

you should have some respect for the technology considering that each dac has a different 'tune' based on the same principle of the strings on a piano.

each string must be tightened or loosened to create the pre-determined tone.

and then again, each string must hold that tone for a long time (some strings will stretch quickly which changes the sound - while others wont)

 

being specific - each 'string' needs to reproduce the pre-determined tone PERFECTLY.

but in the DAC world.. the number of 'strings' that create a perfect tone vary.

another thing to consider is how long will the DAC create the perfect tone.. with age will the tone vary or fluctuate?

 

how well does the DAC create tones while it is excessively hot.

how bout excessively cold?

 

how fast can the DAC create the tone after it has received the information or 'read' the music.

 

how many 'piano keys' can be pressed at once?

 

which 'piano key' echoes and refuses to go away?

 

which 'piano key' requires you to press hard on the key for an audible response?

 

these are laymans terms and should really help you to appreciate the difference in quality when selecting a DAC.

 

they all have different values and characteristics because of the materials used and/or because of the price category they are in.

post #5 of 27
Quote:
Originally Posted by anwaypasible View Post

a DAC is a tone-generator of the 'reading' type.. while a synthesizer is also a compiler of the 'mouth wide open' or 'input' type.

 

basically a DAC is like a grand piano.

picture the information sent in a binary format.

each 0 and 1 off of the page of data = a tone

 

and that means each page can have more than one piano key pressed at the same time which makes a different tone when compared to a single key of the piano being pressed.

 

you should have some respect for the technology considering that each dac has a different 'tune' based on the same principle of the strings on a piano.

each string must be tightened or loosened to create the pre-determined tone.

and then again, each string must hold that tone for a long time (some strings will stretch quickly which changes the sound - while others wont)

 

being specific - each 'string' needs to reproduce the pre-determined tone PERFECTLY.

but in the DAC world.. the number of 'strings' that create a perfect tone vary.

another thing to consider is how long will the DAC create the perfect tone.. with age will the tone vary or fluctuate?

 

how well does the DAC create tones while it is excessively hot.

how bout excessively cold?

 

how fast can the DAC create the tone after it has received the information or 'read' the music.

 

how many 'piano keys' can be pressed at once?

 

which 'piano key' echoes and refuses to go away?

 

which 'piano key' requires you to press hard on the key for an audible response?

 

these are laymans terms and should really help you to appreciate the difference in quality when selecting a DAC.

 

they all have different values and characteristics because of the materials used and/or because of the price category they are in.


A lovely analogy, but confusing, because a DAC, in and of itself, should have no tone, no characteristic sound. A DAC converts digital data - zeros and ones, on or off - to an analog of your music. Period. Without getting into the esoteric considerations of jitter, which is mostly irrelevant in competent, modern DACs, this basic function is either right or wrong, There is no tone, no ambiguity. Errors in translating the data will be obvious and will sound nothing like the subtle tonal differences between analog components. If you have a problem, you'll know. Which brings us to the output section of a DAC. Like every source component ever made, a DAC must have a stage that amplifies the analog signal up to line level (an easy task requiring very little current, making dedicated power supplies and elaborate preamp designs questionable, at least). Your cd player, iPod, old cassette deck...everything, really, all have such a stage. Some manufacturers choose to use this output stage to color the tone of the DAC. Not a good idea IMO, but it is just an opinion. If you like sources colored, enjoy. Others choose to do the best they can to put out a transparent, uncolored signal. A better idea, IMO.

 

With the exception of NOS (non over sampling) DACs and a few other odd, antiquated and dubious approaches, its about that simple. The analog stage, is, by the way, the reason why you would have a free-standing DAC instead of just using the one in your CDP or computer. Isolating that analog stage from the electronics inside the source component (particularly a computer) increases the odds of that signal being very quiet, which has a positive effect on revealing detail and dynamics.

 

P

post #6 of 27
Quote:
Originally Posted by Phelonious Ponk View Post



 

With the exception of NOS (non over sampling) DACs and a few other odd, antiquated and dubious approaches, its about that simple.


Yeah. It is just that simple..... 

post #7 of 27

To answer the OP's question, rather than get into unnecessary arguments about digital conversion *AHEM*....

 

Everything before the DAC is digital (zeros and ones). Everything after is analogue (waveforms).  So the cable(s) between a DAC and an amp are interconnects carrying a "line level" analogue signal.   It's possible to put both in one box.  However, a headphone amp is designed to better handle the rapid movements of the diaphragm in the headphones, just as a speaker amp does much the same thing.

 

The analogue output of a DAC is electrically optimised to feed another component. The output of an amp is electrically optimised to handle headphones or speakers as required.  The requirements are different. 

post #8 of 27

a proper judgement will tell you.. coloring an inferior dac that has a 'colored' yet 'dynamic' sound can result in a linear final output.

 

the only question thereafter is, how long will the components keep their specifications before growing old or 'aging' and becoming colored themselves.

 

but the same can be asked of premium DACS that have no 'colored' sound and are also 'dynamic' in detail.. will they continue to sound good for years and years to come?

 

maybe a slightly colored DAC that has an array of components on the circuit board to specifically compensate for that coloring of the sound - maybe this choice is the best option considering cost and quality rendered a decade from purchase.

 

i'd like to think compensating for a colored DAC requires more work than simply selecting a premium DAC off the shelf and giving it's output amplification.

 

although, i dont like my post being misconstrude one bit.

maybe reading at a kindergarden level is not something you are capable of.. and to each their own.

 

Quote:
Originally Posted by Phelonious Ponk View Post




Some manufacturers choose to use this output stage to color the tone of the DAC. Not a good idea IMO, but it is just an opinion. If you like sources colored, enjoy. Others choose to do the best they can to put out a transparent, uncolored signal. A better idea, IMO.

post #9 of 27

A DAC is pretty much self explanatory: it exactly does what the short term stands for, converting a digital input into analog output (headphones, RCA out to amp).

post #10 of 27

this is a prime example of why one headphone amp is far superior than another amp.

 

Quote:
Originally Posted by Currawong View Post

It's possible to put both in one box.  However, a headphone amp is designed to better handle the rapid movements of the diaphragm in the headphones, just as a speaker amp does much the same thing.

post #11 of 27

i forgot one....

 

how fast can the DAC create numerous different tones after it has read the information?

 

the faster the more 'rich' and 'realistic' the sound will be.

 

how many tones can be created all at once (and instantly after reading the information) is really the absolute beautiful difference with DACs.

once you get into the premium line of DACs.. the options listed in the above sentence is what you will be selecting from.

 

just like speakers from the 60's and 70's

they are capable of playing tones FAST

 

and now.. todays speakers can play tones FAST and also play more than one tone at once.

 

(well actually.. the 60's and 70's saw speakers that could play more than one tone at once.. and today the speakers are doing dozens and dozens of tones at once)

post #12 of 27

Mind you that a DAC is not creating tones, but rather electricity, or the analog signal.  The DAC then sends that voltage to the amp and the amp amplifies that signal by so much.

 

Digital to Analog......

 

Binary [1's and 0's] to Electrical power

 

 

Mind you the amp typically has a large input impedance, like 10k ohms, so the output power of the DAC is irrelevant.

post #13 of 27

well, true.

if you turn your home theater receiver 75% of the way up and grab the bare wires that go to your speaker.. you are gonna get shocked and zapped by electricity and not a 'tone'

 

and it is the exact same thing with DACs.. they dont produce a 'tone' like a speaker does.

it is electricity like grabbing the speaker wires as i said.
 

 

another good point to mention is the input impedance remark.

a solid reason why one headphone amp is better than another is because of the input impedance (also known as resistance)

 

if there was little resistance, the electricity from the DAC would be free to flow on to the next step (much like water in at the panama canal where they raise and lower boats) .

if the water was free to move to the next step or 'layer' the whole process would be perceived as faster or 'quicker'

 

so in laymans terms once again.. there are specifications that are not revealed to the general public to help them make a choice.
 

Quote:
Originally Posted by ccbass View Post

Mind you that a DAC is not creating tones, but rather electricity, or the analog signal.  The DAC then sends that voltage to the amp and the amp amplifies that signal by so much.

 

Digital to Analog......

 

Binary [1's and 0's] to Electrical power

 

 

Mind you the amp typically has a large input impedance, like 10k ohms, so the output power of the DAC is irrelevant.


Edited by anwaypasible - 6/20/10 at 10:12am
post #14 of 27

DAC is short for Digital to Analog Convertor.

The name alone should give you a hint about what it does..

post #15 of 27
Quote:
Originally Posted by Phelonious Ponk View Post


A lovely analogy, but confusing, because a DAC, in and of itself, should have no tone, no characteristic sound. A DAC converts digital data - zeros and ones, on or off - to an analog of your music. Period. Without getting into the esoteric considerations of jitter, which is mostly irrelevant in competent, modern DACs, this basic function is either right or wrong, There is no tone, no ambiguity. Errors in translating the data will be obvious and will sound nothing like the subtle tonal differences between analog components. If you have a problem, you'll know. Which brings us to the output section of a DAC. Like every source component ever made, a DAC must have a stage that amplifies the analog signal up to line level (an easy task requiring very little current, making dedicated power supplies and elaborate preamp designs questionable, at least). Your cd player, iPod, old cassette deck...everything, really, all have such a stage. Some manufacturers choose to use this output stage to color the tone of the DAC. Not a good idea IMO, but it is just an opinion. If you like sources colored, enjoy. Others choose to do the best they can to put out a transparent, uncolored signal. A better idea, IMO.

 

With the exception of NOS (non over sampling) DACs and a few other odd, antiquated and dubious approaches, its about that simple. The analog stage, is, by the way, the reason why you would have a free-standing DAC instead of just using the one in your CDP or computer. Isolating that analog stage from the electronics inside the source component (particularly a computer) increases the odds of that signal being very quiet, which has a positive effect on revealing detail and dynamics.

 

P

 

This post was extremely informative. My understanding of this post is that all DAC's should be the same then? if they aren't converting the 1's and 0's into the correct analogue signal then the music would sound completely different? Does that mean the Cheap DAC's should cost the same as the expensive DAC's? Also what do you mean by quiet? Is this to stop sensitive headphones from hissing or hearing an electrical noise? When I connect my e10's to the line out of the PC mobo, I get electrical noise. Even when I connect the speakers to the mobo line out and then my e10's to the line out of the speaker, but the noise isn't as loud. Does this have anything to do with this topic?

 


 

 

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