May 27, 2016

Massdrop 101: What Is A DAC?

With millions of songs at our fingertips every minute of every day, it’s easy not to think about where our music comes from—and how exactly it gets to us. The truth is that whenever we play a song on our computer, MP3 player, tablet, or any other device, the music undergoes a complex (but nearly instant) process of conversions, adjustments, and modifications before it hits our ears. One of the most important steps in this audio playback chain is the conversion from digitally stored files into analog signals.
The Digital Revolution
Before internet streaming and other modern technologies came around, everything we heard was stored physically. To save a song or another piece of audio, you needed physical space and a tangible format to store it in (think records, tapes, eight-tracks, and the like). When a signal was recorded, it was saved in analog format, which uses continuously varying signals to represent the fluctuations in air pressure produced by the original sound.
Up until the 1970s, analog was virtually the only way to store audio. Today, the majority of music is stored digitally. Digital format describes a piece of information that is stored in binary using a series of ones and zeros. By storing all of the bits that make up a file in binary, this process drastically reduces the amount of space that files take up, as well as the cost of distributing them.
How It Works
Although today’s world is almost completely digital, our brains still process information in analog. Because we can’t hear ones and zeros, that information has to be converted back to analog before it can be played. Enter the digital-to-analog converter—or DAC.
A DAC uses a series of protocols and technologies to initiate the digital-to-analog conversion. With a combination of hardware, software, mathematics, filters, and a small pre-amplifier to boost the signal, a DAC is able to convert an abstract binary pattern into a physical quantity that can be discerned by our music players.
Virtually every modern device has a built-in amplifier, and the same is true for DACs. Because there are so many features squeezed into our phones, computers, and tablets, manufacturers often cut corners on technologies that are less applicable to a wide audience—especially DACs. Most built-in DACs can adequately convert our music from digital to analog, but to do it well, a separate stand-alone device is necessary. If you want all of those zeros and ones to sound as good as they did when they were originally recorded, you need a high-quality DAC.
Why Get A DAC?
A stand-alone DAC offers more detail, better power supply, and a cleaner, more pleasing sound signature than the miniature versions built into most devices. They’re also capable of playing high-resolution files. While many people are contently listening to MP3 files (traditionally considered to give listeners the most bang for their buck), there are other file formats that can deliver an even better listening experience.
When an MP3 file is encoded, it gets compressed to save space. When the file is compressed, it loses some of its detail and originality, and is then known as a “lossy” file format. Formats like FLAC, Monkey’s Audio, and WavPack are encoded without compression, leaving all of the raw data as was originally recorded—which, in turn, takes up much more space. A high-end DAC is designed to more accurately reproduce uncompressed files, giving listeners a more robust version of what was originally recorded. Some are more flexible than others, allowing users to decode extremely high-resolution DSD files, too. It all depends on the type of DAC.
It should be noted that although a dedicated DAC can enhance our music, the differences will be hard to notice without a decent amplifier and pair of headphones to go along with it. A good DAC is transparent. It converts a digital signal in the most accurate way possible. If the original file sounds bad, it usually won’t sound better just because it’s been converted with an expensive DAC.
What Now?
The best way to find the right DAC is to try one out for yourself. A good place to start is a DAC/amp combo, which offers all the benefits of a DAC and an amp in a smaller package, at a more accessible price. There are a few reasons to try separate components. You may want to understand and have control of each item in your system, and to personalize the sound just for you.
Any questions? Leave ‘em in the comment section below, and someone from the community will be happy to help. Have personal recommendations or a cool audio setup to share? We’d love to hear about them—and see pictures, too! Want to learn more? Read another Massdrop 101 article, “What Is An Amp?”, here:
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Would it be worth to get an AMP/DAC Combo like the Schiit Fulla 2 for a headset that has 150ohm and a Sensitivity of 108 dB S.P.L. at 1KHz?
If I have powered monitors, can I still buy a DAC with an amp combo?
Yes if it has a line-out. Otherwise you would be double-amping, which is not the best but "might" sound OK depending on your setup. Beware of the power output of the amp and the max power input of your speakers, you could blow them away if not careful and just crank the volume of the amp to 100%.
that Violectric stack. drool.
Vio stack for HE 350 lmao
I use a FiiO E17K which I found gives a much better (less muddy sounding) sound than using my laptop output directly. And that's just with some Ultimate Ears IEM's, not some huge open backed headphones that need a lot to drive them.

I mainly opened this article to see what that DAC in the header image was. Violectric wasn't a brand I'd heard of so went looking them up... I don't think I'll be buying one of those in a hurry!
FiiO E17(k) are two very good products. Can anyone help with how to change the battery in the mark I?
Where can I get that dinosaur pot?
where can I get that dinosaur pot?
I literally Googled 'Dinosaur Pot'. You should try it some time.
This explains a lot, thank you. Always wondered why people got headphones that wouldn't fit my 3mm audio jack.
thanks a lot for sharing valuable information, you summed up probably an hour of research :D
cool. Thanks!
But then aren't the built in dac and the odac identical in the objective sense?
"Objective sense" means as measured by test instruments. To make those measurements, the DAC has to be operating in a complete system, like I described. You can see what the ODAC Rev.B objective measurements look like here:

I think what you mean is comparing specifications between the DAC chips themselves as provided by the chip's manufacturers. You'd have to have a fair amount of electrical engineering background to know how to read and compare those numbers, and they still wouldn't tell you about the way ODAC or macbook chose to use them. For instance, the original ODAC would produce a lot of distortion if the USB port it was plugged into had a particular kind of capacitor on its power lead. There's a lot of interactions like that between the chip and the surrounding components (though rarely that severe) that DAC specifications just can't tell you.
(prob noob q) I just found out that my macbook has the following DAC in-built:

keeping this in mind I was wondering if there was any point getting a DAC that is equal to or inferior to the ODAC. The in-built one seems pretty good to me.
Hard to say, there's a lot more that goes into the sound quality than just which DAC chip is used, like the design of the circuit surrounding the DAC, the amplifier, the earphones, the purity of power to the DAC, etc. Only way to tell for sure is to try it and compare. That's why people go to meet-ups.
but what do things like 24bit/192khz mean? I was expecting to get that here
Those two numbers refer to the sample resolution and the sample rate. Digital music samples the analog signal several times per second, and turns the sampled voltage into a number that gets stored in the music file. The most common music files will be 16bit/44.1khz, the quality of a CD, which means the voltage is represented by a number with 16 binary digits, with 44,100 of these samples per second, for each of the two stereo channels. 16 bits divides the full voltage scale into about 65,000 equally-sized steps. 24 bits would divide it into about 17 million steps. The more the steps, the smaller they are, and the more precision with which the voltage is represented.
Whenever i introduce a noob to the world of DACs ,Openbacks, HiFi audio, i always ask them for a song which they either know by heart all the drops , highs ,; something special to them. And i proceed to show them the differences line out from a phone/ laptop , line out to DAC , digital out to DAC .. Each progression leads to a higher jump of eyebrows. It's something special to see. More often than naught , they always say " I had never heard that before " or " was that always there" .

Grado SR325e
JDS Labs Element
That's an excellent method to highlight each piece's benefit too!
This is such a great way to do it.
I did something like this to explain to my friend the wonders of soundstage with open back headphones.
His amazement when he listened to virtual barbershop with his lame convenience store sony earphones and compared it to my shp9500s. I have ruined his world on computers before and now headphones..I have enlightened him!