[zowki]

What do DACs and amplifiers do to sound and which is more important in the audio equipment chain?

 

[Buyer no 1]

IMHO they are equally important. It dosen't result in high SQ having a high quality amplification of a low quality signal. And it dosen't result in high SQ having a low quality amplification of a high quality signal.
 
In my experience, in the world of head-fi, a high quality signal will cost a lot more than a high quality amp, though. 

 

[JRG1990]

Probley the amp cause it can add more noise and disortion to the signal than a dac, a high quality dac and amp can be had for little money, look at the fiio E7/E9 and audio-gd range.

 

[jackmccabe]

There is little need to go higher end than a fiio e9 and a uca202.
Pat that I found there are almost no improvements to be had.

 

[Yoga Flame]

It depends on what equipment you currently have.
 
For hard to drive headphones, a good amp is necessary to meet the basic power requirements. An underpowered pair of headphones may suffer from weaker bass, audible distortion, or just simply not being able to get loud enough to enjoy. But if you have very efficient headphones like the ATH-M50, then even pretty much any portable player will be able to drive them well. Still, a power hungry headphone like the HE-5LE will still basically sound like an HE-5LE when plugged directly into an iPod. Though you can tell that something is missing.
 
As for DACs, it depends on what your baseline is. If you are currently using the onboard sound chip on your computer, or if you can hear a background hiss on your sound card, then upgrading your DAC will make an obvious improvement. The iPod is a good commonly available standard to compare against. If your sound card sounds worse than an iPod, then it is a prime target for upgrading. Beyond that, the improvements with every upgrade start to become more subtle.
 

 

[snaps11]

I noticed a bigger difference with getting a dac then getting a amp.  But then again you really do need both =) .

 

[khaos974]

I'd say that an amp has more chance of getting it wrong than an DAC because of the great variety of loads it has to face.

When choosing the DAC, the criteria are pretty much universal, low distortion, high linearity, low noise and high dynamics, jitter rejection, the rest is functionality, those criteria are universal.

On the other hand, besides the previously written criteria, an amp also has to satisfy criteria of power, max voltage and current capacity, stability, output impedance... Those criteria will determine how well the amp will work with a given transducer. Some amps will work with with a transducer and no another and vice versa. That's why I consider choosing an amp more difficult than choosing a DAC.

 

[Uncle Erik]

The amp, by far. I'm not sure if there is any DAC on the market that has distortion in the range where humans can hear it. Jitter is a solved problem, too. Like distortion, jitter rates may vary, but all of them fall below what people can hear. The only big variable left is output voltage. If one DAC has a higher output than another, the louder one tends to sound "better" since we're pretty well attuned to hear differences in volume and louder=better to our brains. Of course, if you level-match DACs, they all sound about the same. Build quality and reliability are different matters - you'll want a DAC that's well-made so it'll hold up. Also, some DACs put (unnecessary, IMHO) tubes in the output to color the sound. Whether that's "better" to you is a matter of opinion.

Amps have a wider variety of sounds. Solid state has a more focused range than tubes and tend to have flat impedance curves. Tubes usually have a lot more variation in output impedance, usually a curve. Impedance tells you how well power transfers. When the impedance curve changes over 20Hz-20kHz, it means that power delivery varies. Further, you'll notice that headphone impedance changes over a range, too. Impedance rarely stays flat throughout the range. So what this means is that power delivery varies depending on how the output impedance varies along with the headphone impedance as frequencies vary. Since we're sensitive to differences in volume, the dance of output impedance and headphone impedance gives different sound signatures. Measurable ones, too. Further, tubes introduce noticeable distortion sometimes and they have different output curves (separate from impedance), too. Further, tubes have different output curves depending on bias voltage. The same tube can sound different in different amps, depending on where the bias voltage is set. And there's more to it, but you get the idea. All this stuff is real, too. You can put them on various test gear and demonstrate the differences.

So the amp you choose introduces a lot of variables when it comes to the headphones you're driving. No two behave the same.

A DAC mostly varies by output voltage. But you can adjust that with a volume knob. This is why I don't make much over digital sources. Reliability aside, they're pretty similar. You'll pay a lot for fancy cases and new chips roll out every year or two, but I don't see much reason to upgrade.

In terms of what's important, the recording is most important. If you have a lossy file or a brickwalled track, no amount of gear will help. After that, the headphone is hugely important. Amps play a role in fine tuning, but aren't as important. The DAC isn't very important at all and ignore the snakeoil. You'll pay a lot of money for something where no difference can be detected.

 

[bumblingbooby]

Nice post Uncle Erik. I like your common sense approach to this caper. 

 

[Lenni]

DAC.
 
upgrading from the DacMagic to the 'Young' DAC was the best upgrade I ever made. for the first time I was truly satisfied with sound; OK  almost satisfied, but that's more to do with the speaker's limitation that anything else. but I am enjoying it a lot more now than I used to. some may say that spending past the price point of the DacMagic is diminishing returns. not in my experience. to me I got into diminishing returns the moment I bought the DacMagic, that is.
 
of course, everything is important (amp, coughcables, etc...) to the final result, but the DAC was the best upgrade for me so far.

 

[zibra]

My vote is for source and I dont agree with coloured sound from tubes output. It must have been bad tube DAC then

 

[Uncle Erik]

The whole "source first" thing is from a marketing campaign spawned around 40 years ago by Linn.

Back then, a good turntable truly was important. It still is, when it comes to analog.

But digital happened in the following 40 years. Digital is awfully good, even on a $29 DVD player.

Also keep in mind that the marketing campaign was kicked off by a guy who thought that having an undriven speaker in the room ruined audio quality. No joke. He thought that having an unpowered speaker or two around ruined things. He had his backside handed to him in some double-blind tests, though. Still, this mythology hangs around like a bad cold. Digital sources just aren't that important. Level-match them and hear for yourself.

Great audio has never been cheaper. The problem is that people are now hung up on status symbols, not quality.

 

[Willakan]

Hmm, on a slightly OT note, do you think that there will be a swingback away from fashion towards audio based on, you know, science and rationality? 
 
We may, as a community, shout "BOO HISS" every time someone buys their Beats by Dre and other popular headphones aimed at the average consumer, but if it gradually brings more people to hi-fi, and those people are unused to the utter ludicrousness of high end audio, surely this will turn out to be a good thing? I'll take someone who has some cheap headphones they saw advertised but is interested in gaining more bang-for-the-buck sound quality over someone who insists that DBT is somehow flawed and that everything less expensive than their setup is clearly a "compromise" due to the lack of nice cables/stupidly expensive boutique NOS DACs ect...
 
One can be educated (Wow, that reads snobbier than it sounded in my head), the other is probably beyond hope 

(how can you argue with people who will willingly dismiss any rational argument with "I heard it. And therefore it was real"?)

 

[zibra]

Its just my subjective opinion from test listening few headphones on some amps and dacs. of course amp is needed for driving headphones but paired with weak source headphones wont shine as it could. So generally Im fan of sentence "you have such sound as your weakest system component" - and if your chain starts from weak source then you possibly cant get the best of sound. And it has nothing to do with price of component as Im also fan of DIY - so no marketing hype.

 

[Uncle Erik]

zibra, you are working from a false assumption that's freakin' everywhere here.

The bad assumption is that there are significant differences between digital sources. Further, that the price of the source is some sort of indicator of quality.

The truth is that all digital sources are pretty much the same. Some will claim better specs than others, but that doesn't mean much because all the specs are usually below what humans can hear. The major issues with digital were solved 20-some years ago. DAC chips have evolved to get smaller, cheaper and integrated with other functions.

There's also a lot of nonsense from manufacturers. Do you really think any of them would come out and tell customers that their new DAC is pretty much the same thing as their 1997 version?

Willikan, I agree. The snakeoil destroys credibility. When people think of audiophiles, they remember stories of people buying $8,000 cables and assume that everything high-end is nonsense. Even worse is if someone starts to ask questions about cables. First, they realize that there's zero evidence whatsoever. Second, they're called a "hater" because they asked questions.