If you haven’t already, first read the entry “What is a DAC?” Now that you have a basic understanding of what a DAC is, the answer to whether you need one is based off a few things: If the DAC in your existing media player isn’t very good, then yes, you might want to invest in a better DAC If the output from your media player is compromised in that it sounds like static or generally the connection is bad, then yes, you might consider an external DAC If you need more power to drive your headphones/speakers and you’re 100% against amplifying an already amplified signal (think plugging an amp into the headphone jack of your iPod), then yes, you should consider an external DAC If you are obsessed with getting the absolute best quality sound out of the headphones you have (and you have an ultra high-end set of headphones) then you should consider getting an external DAC If the sound coming out of your existing media player already sounds great then chances are you don’t need an external DAC. For example, the DAC and accompanying circuitry in iPods and iPhones is considered to be pretty good. The shortcoming of these devices is they have less powerful amplifiers in them so you can’t drive higher impedance headphones. Personally, in this case, I’ve found that just hooking up an external amplifier WITHOUT a DAC sounds wonderful. MANY devices use the same chipset for their DAC’s. The magic is not necessarily in the DAC itself but in the accompanying circuitry. I won’t cover that here as that’s a topic that could have a book all to itself, but, typically what you’re looking for are high quality components that take the newly formed soundwave from the DAC and turn it into a clean, accurate, amplified signal that is free of noise introduced by other circuit components. So, when people ask if they need an external DAC, they’re really asking if buying some external device will improve the sound of their existing media player – that completely depends on the components used in the existing device vs the external DAC device they’d be purchasing. Lastly – not ALL media devices will support using an external DAC. iPods and iPhones specifically are not designed to work with external DACs. There are some hacks and work arounds, but most people would not be willing to do what’s required to get it working. Computers are perfect candidates for using an external DAC, especially if you have a sub par, on board soundcard. Newer Android phones and tablets support the use of an external DAC with the use of an OTG cable. I know for a fact that the Samsung Galaxy S3 and S4 both work well with several of the Fiio DAC’s which I’ll list below. Examples of external DACs: http://www.headphonereviewhq.com/get/e17 http://www.headphonereviewhq.com/get/fiioandes http://www.headphonereviewhq.com/get/fiio-e10 OTG Cable for connecting to an external DAC: http://www.headphonereviewhq.com/get/otgcable
DAC is an acronym for Digital to Analog Converter. Essentially the job of the DAC is to take your digital audio, MP3, AAC, FLAC, WAV, etc. and convert them back to the original form they came from – audio waves. Digital audio conversion is beyond the scope of a simple FAQ, but there’s a great write up over at Wikipedia – http://en.wikipedia.org/wiki/Digital_audio. I encourage you to head over to that link and take a look at the first couple of pictures on the right side of the page. They give a very good visual indication of what happens when you convert an audio signal to a digital format, and the job of the DAC is to reverse that process. Essentially you’re trying to take that “block formed” digital audio and turn it back into a sound wave as that’s what’s needed to drive speakers/headphones. A few technical details of DACs. MOST, but not all external DACs are designed to work via USB interfaces. This tells you they’re ideally set up for use with things like computers, cell phones, etc. Some external DACs have additional connection options such as SPDIF inputs, coaxial digital inputs and the like. An example of a DAC with these additional connectivity options is the Fiio E17.
This is a question I’m asked quite frequently and the answer is, it really depends on the amplifier and the headphones. In a perfect world, NO, an amplifier would not make your headphones sound better because the job of the amplifier is to provide more power to drive your headphones – Period, end of story. HOWEVER, most amplifiers introduce their own characteristics to the sound being amplified. It could be that the amp slightly boosts the bass region, or amplifies the midrange slightly, etc. There are some amplifiers that are extremely neutral, so in that regard your headphones won’t sound any better, but they’ll be able to get louder with the amplification. And that’s why it’s not so cut and dry when picking an amplifier to pair with your headphones. All headphones and all amps have their own sound quality characteristics and a pairing that might work wonderfully for one set may not be so great with another. To wrap up here, YES, it is possible for an amplifier to make your headphones sound better, but it’s highly dependent on the amplifier you choose to pair with your headphones. In my opinion though, the best solution is to get a set of headphones that sounds wonderful out of the box and go from there.