!remindme 1 day

I can't say I know how or why, but I can tell a difference with and without an amp for my headphones. It just makes it sound slightly more filled out, like the music has depth and life to it.

Your headphones probably would still sound good without an amp, but using a proper power source just unlocks their full potential really.

Oratory1990s comment on r/headphoneadvice is worth a read.

https://www.reddit.com/r/HeadphoneAdvice/comments/rsvir3/what_does_an_amp_really_do/hqos93o?utm_medium=android_app&utm_source=share&context=3

What does it mean? Well, if you have an audio shop near you, try and audition the exact same pair of headphones, with the Apple dongle and then with a dac/amp, and you decide for yourself (: If you detect no difference, that's your money saved (or put into a new pair of headphones more likely, knowing us)

Personally if you ask for my experience, I tried this with an Edition XS. At pretty similar volume levels, with the Apple dongle (and blindfolded at home where my headset was plugged into my pc's motherboard) I noticed the sound was pretty congested. Everything's still happening, just blurred into each other as compared to with my ifi zen dac v2/questyle m15.

As long as you achieve comfortable listening level you are good to go. Do not worry about what audiophiles say. It is mostly their imagination and copying the marketing department.

Short and semi-wrong simplification: a small amp, like a phone-amp, can produce effect peaks that are sort of technically sufficient to blast your ears off even on a pretty high impedance driver (like on the hd600). But sustaining a more complex sound-picture, and still creating the dynamics (i.e., the differences in volume that are, presumably, in the recording of what isn't an electronic metronome) needs a longer and higher effect threshold (that on normal listening volumes might not be very high, but still significantly higher than a phone-amp).

So.. when you test the physics of it, you could get results on a very light amplifier - and that would even correspond to your listening experience - where the amplification required to produce an accurate enough tone for a short amount of time is extremely light. I've done some testing that is similar to what produces the effect-curves and frequency responses you see on some of these tests - and for short enough intervals on reasonable volumes, a massive effect threshold isn't necessary. At all. Like a 4W laptop amplifier competes with a Chi-fi star from Marantz that happily drives two large front-speakers on 2x100W until the glasses ring in the cupboard.

But if something more complex happens in the music (and the source you're playing back has a higher density in the actual recording - and not that it has been "upscaled" to 320kpbs mp3 or something like that - so that you're even going to be able to hear anything here other than the boom on the lower tones, and various other things that are just not produced in the actual speaker-driver) -- then the tones/music will change once you have a sufficient effect threshold to draw on.

It still doesn't need to be very high, which is why a decent enough carryable amp is enough (and why Chi-fi is a thing - the level required for more than decent enough playback is not actually that high. And the design-need to put in incredibly high ohm speakers also isn't really there, because people don't have power-grid noise or things like that that really cause noise - we're not at that level in recording or monitor sensitivity on your typical home-product that plays back, at the very most, 320kbps compressed audio, sent through any amount of noise-filters on the way). The idea that a cd-recording, that was compressed down to a cd-format in the first place, that then was washed through the cd-player's horrible variable codec, that then produces a signal that is washed with a noise-filter before it's amplified, and then also reduced slightly again through the amp -- needs a million Watt amplifier from Klipsch or Hegel to sound good on a pair of normal-sized speakers in a living-room is beyond ludicrous.

But basically, on the first step, you're looking for an effect output that can make the headphones work consistently. If you have to turn the volume/effect very high up to get much of anything, you can hear the effect very easily when you play something else than a test-tone, in that the difference between loud and quiet is basically not there, or that you're missing reproduction of some frequencies when there are other things happening as well. I.e., you get the test-tone, but while doing two, there's a variation in the output.

The second step is getting something that has a high enough threshold so that in complex parts of the recording (some people notice their blip-boop music not having a great enough bass-crunch while the keyboard is tapping an a-tonal horror that would make Schoenberg flutter in delight) will be the same when you add another element to it. On classical recordings you could have the same effect because of noise around where the recording was made, for example. So that - if the recording wasn't leveled through a press and then cut out in an a4-shaped cutout - that noise from the chairs and various echo-bits and resonance would actually sound fantastic on a good setup (as much as the recording equipment allowed). But when played back on a kitchen-player (the gold standard for "modern" digital formats), the recording would sound inconsistent, unpleasant to listen to, and dry and empty.

That effect-threshold for reproducing something with dynamics on a 300ohm headset is not very high. But it is higher than a phone-amp's, which is typically reaching peaks of the effect the power-supply can handle or is designed to handle at around 20ohm. The "gold standard" for mobile phone headsets, as with bluetooth headsets, is basically then to produce headphones that are in the 16ohm range.

That doesn't mean they suck, it's just that higher impedance speakers would sound like trash on that system (in certain situations). To make things worse, though, some of these large headsets also work, and are designed to work on lower effect. So you don't get muted or garbled tones on an under-amplified system (which again brings with it an endless amount of design-for-most-common-usage drawbacks). It's just that you're not getting out what the headset can produce.

Which admittedly very often isn't an actually high level. For example, if you can have a sustained effect without drops through, say, 5 seconds, on a very low effect amp (such as a phone-amp - they do exist), you can actually get away with that on low volumes on fairly high ohm speakers. Because what you were looking for was not to produce peak effect on all frequencies, in some astonishingly modern music recording that is unfit for human consumption -- but a lot less than that.

Or put in a different way, the difference between "hi-fi" and "crap" was actually the amplifier's ability to output the desired, still very low, effect for 1 second, instead of having a drop-off after 0,3 seconds. And that then retained all the dynamics at a humanly listenable volume, produced all the detail, etc., even though the amp is not going to melt your ears (at least literally). Note that you also have these effect-drop offs on more expensive amplifiers, just in a different range.

Wow this got quite long, but here you go:

I own a FiiO K5 pro and the Xduoo TA-26 and use both, but to be honest here, my onboard audio can handle the HD 6XX just fine. I tested it a few times and I really would love to say it was worse, but it was honestly fine and, as far as I remember, not much different.

I've yet to plug my headphones in some amp-dac setup and say: "wow, what a difference!", so there's that.

My setup is more for looks and the feeling it gives me. Warm, slightly glowing tubes, dedicated volume knobs, all of that is very nice, but I'd be lying if I would tell you that these amps blew me away in comparison (the TA-26 is just solid state sound that's slightly fuller, like 10% difference at best). I also believe that dacs barely differ from each other if their goal is a neutral soundprofile. The FiiO works just as well as a 1k dac I've tried at a friend's place. He was quite shocked, which I found very entertaining lol.

But take this with a sprinkle of salt. I am sure that not every onboard audio solution is as good as dedicated dacs and amps. It's just my motherboard that works fine and others might not. My phone with the EU Samsung dongle doesn't get loud enough and the bass is actually reduced and my Nintendo Switch also seemed to be lacking in some aspects.

In the end it's up to trying things out. A and B testing with matched volume, finding out by yourself if there's a need for amplification. Heck if money isn't an issue then go nuts, it's a great flex, but on the other hand there are many on here that want the best bang for their buck and that's totally fine.

So we should stop lying and tell them the truth: it always depends if you actually need thing xy, so try before you make your wallet cry. Heck even I'm a little bit biased because all of this stuff I purchased was expensive for me. But I am really trying to swallow my pride here and tell you what I've actually experienced.

As and example: my last few weeks consisted of swapping tubes like some lunatic only to be sitting there, sad and alone in my room, trying to deal with the fact that there's barely any perceivable difference between all of them.

TL;DR: I sometimes wish some devices made as big of a difference as some people claim. In the end you have to try things by yourself and decide. I personally wasted some money (on tube rolling) that could've been used for something else.

Edit: oh btw, I didn't talk about things like hissing sounds from some aux ports or USB ports picking up GPU sounds and such. Some dac-amp solutions might help here, especially optical cables (these fixed the issue of my tube amp picking up random noise from my PC).

With dynamic driver headphones, where the impedance changes over the frequency response, the output impedance of the amplifier determines the final frequency response that you hear. It is for this reason that sometimes people run for example the HD800S on tube amps, along with more second order harmonic distortion which produces a more "euphoric" sound. The high output impedance however is not unique to tube amps and can be reproduced by simply adding a resistor to output section of a solid state amp.

Powerful amps give you more headroom. I'm going to give a simplified example. Let's say in a certain song the drums are 10 dB louder than the vocals. Since dB is logarithmic, you can perform addition and subtraction on the numbers and maintain the difference in relative loudness. An under powered amp tops out at 90dB for a given headphone. If you turn the vocals up so that they are 90dB, the drums are still going to be 90dB because that is the limit of the amp. If you've got a more powerful amp that can drive the headphones up to 110dB, it will comfortably reproduce vocals at 90dB and drums at 100dB.

Amplification is a very complicating topic. You may come across SINAD for example, but they don't tell the whole story. But in general if you get an amp from a reputable brand which delivers high power you are good to go

JDS Labs (they make the Atom and Element series) once put a blog post discussing this: https://blog.jdslabs.com/2015/06/power-is-volume/

For every frequency, headphones have slightly different impedance and sensitivity (power needed to product a certain volume). In principle if an amp is underpowered the headphones can sound loud enough but the frequency response is distorted, particularly towards the extremes, because the amp can’t power those frequencies. This is why people say the bass and treble are lacking.

Very generally, I’ve found that if a pair of headphone produces “listenable volumes” but are not actually loud when the phone volume is at max, then they’ll perform better with a more powerful amp.

I always hate the terminology of “properly power” simply because it implies that many amps cannot do it. Which isn’t true. Many amps are capable of powering most headphones, but not all amps deliver power as cleanly as others at certain settings. I actually had this question recently and got a very lovely short essay from GoldenSound. It basically came down to, “just because an amp can technically do it, doesn’t mean that it does it well.” I think the best example that I can give is my Element 3 vs my Apple dongle when powering my 250 Ohm DT 770 Pro. With the Apple dongle there is a ton of high end hiss that that goes beyond what the 770 is known for. It’s palatable, but definitely not pleasant. But with the Element 3, none of that is present. Different topologies allow for some amps to work better at lower gain settings. Hence why the Apple dongle has sizzle and hiss, but the Element does not. Ideally, you want to introduce as little gain into your signal as possible since gain will color the sound before it even reaches your headphones.

It simply depends on what you count as "listenable" volumes. Sure an iphone can power hd600's to a low level of volume which may be perfectly "listenable". The issue is power required to raise the volume is not linear, each extra decibel requires a larger increase in power than the previous one.

Now lets say you're not listening to highly compressed professionally produced music which has a tiny dynamic range, lets say its amateur produced with a massive dynamic range. Suddenly you need 10x the power to get to that same "listenable" level.

Then there is the question of what is "listenable"? If you're trying to recreate the experience of a concert you may be looking at transient peaks of 100db, that will take way more power for the hd600's than an iphone will deliver.

At the end of the day though, the question is are you happy with the volume you're getting in all scenarios? If yes, then there's no problem.

Just wrote this in reply to a comment linking to some of oratory1990’s thoughts on amps. I am linking here so OP can see.

Amps generally are reducing voltage for headphones from line level (since they are mostly very sensitive or efficient) - the amp is outputting less voltage than it receives but is increasing current to be able move and control the physical driver membrane via the alternating electrical signal applied to a dynamic driver’s coil and magnet system. Same goes for most types of drivers, with various quirks.

https://www.reddit.com/r/headphones/comments/z5wwmn/comment/ixzbgik/

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I was playing around with low, mid, high gain, with varying 0 to 5.5db bass shelf. No matter how much I eq'd the bass on low gain it sounded like an iem, in my head. High gain gave me subwoofer like slam. This gets even more prominent with speaker amps which is what all rich people who have spent years searching for end game buy hundreds of amps end up with even if its moderately priced. Please note this is just for hard to drive planars and earspeakers. High power usually means more noise and is not ideal for sensitive headphones.

Let me explain this phenomena on a larger scale with speakers. I have Martin Logan ESL’s (electrostats) and I was running them both from an integrated tube amp. The sound was great but I saw that my local audio guy had two emotiva mono blocks on sale for $750 a piece (normally $1100 each) After setting them up properly, which did require removing our sub as the adapter caused one speakers to be quiet) I found that I really didn’t even NEED a subwoofer as they were being sufficiently powered (given a full strong signal.) The highs and clarity and dynamics and even soundstage were improved. These mono blocks must weigh around fifty pounds each and boy let me tell you I do not want to move them again but they supple class A or class A/B power with a switch. Try out better amps, but you might want to get better speakers down the line too!

The hard part of this is that explaining sound can only be done with funky words like sparkly, bright, muddy, sibilant, etc… The best thing you can do is give a proper amp a chance and compare those same headphones out of an iPhone and out of an amp. Trust me, you WILL hear the difference (hd600s are great for this cause of the 300ohms resistance).

Best explanation I found as to how / why it truly matters is that if you're at 90% Volume on a song because your phone can't power your headphones all the way.

Say you're listening to a song with a very high dynamic range like something classical or some Jazz.

The soft portions of the song that are very quiet all the way to the loud booming portions could have a difference of 25db.

When you're at 90%volume, your headphones can't put out more than the Maximum, and so you lose out on all that extra detail and range the song has.

And when your headphones aren't powered enough to bring that low small whisper portion of a song into an audible level, and then be able to bring the louder booming portions into it as well, then you're losing out on either the sound from the quiet tones or the more loud higher details. And when it's not properly powered, that's the issue you struggle with and face.

There may be some flaws with this, I'm not an engineer. This is my understanding after reading a fair amount on it and asking some similar questions.

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It means nothing; it's just a way for people to justify amp preference with something that sounds technical.

Technically, dac amp or dac + amp able to achieve 100dB SINAD at 1mW will mean it can drive properly.

For HD600, dac amp capable for 1Vrms output is good enough. 2Vrms is even better. Anything more than 2V will just deteriorate with increased in noise.

To make them loud enough

If you really want to delve into it, look into the "equal loudness contour". It's a nuanced topic, but you can always start with Wikipedia:

https://en.wikipedia.org/wiki/Equal-loudness_contour

TLDR; The human ear is most sensitive to the midrange, so you need significantly more SPL for bass and treble frequencies to be perceived as equally loud.

(Side note: Without developing careful critical listening skills to be able to perceive these differences, this debate always devolves into a pointless pissing contest, from both sides.)

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Not this again

I have the Lcd x, a headphone that can be powered by a childs wish. The difference between a Qudelix 5k and an RME ADI 2fs is : Literally the headphones go from “huh, sound pretty good” to “jesus christ are they performing behind me??”. In this case the headphones sound fuller, more detailed ( silly but you can actually hear things more separated from another ) and persuasive

100%

The OP is asking for a short yet technical answer.

No one seems to reply with such criteria.

It's just volume. Mismatched extreme cases of impedance can slightly alter the sound, usually for the worse by adding slightly extra bass. My powered Roland workstation's headphone jack is an example, it gets incredibly loud easily and makes some headphones bassier. Not desirable and an extreme case out of dozens.

Out of all the audio interfaces, amps and even dongles I've used in shops, studios and from home, they basically sound the same, just can deliver different volume.

Soundstage widening, extra detail, cleaning up frequencies, all of that I don't get and even if that was true, it's going to be a result of it altering the frequency response of headphones which is a bad thing. I don't want a coloured amp, I want an accurate amp.

Save your money in this marketing speak dominant hobby.

>I’ve heard some say that properly powering a headphones adds bass/treble.

Funny enough, it's the opposite. If headphones are properly powered, they have LESS bass/treble. Because it usually means that amp and headphone are impedance matched. Which is not the case with Sennheisers like HD800s - their high impedance means they'll sound good out of any source straight away.

It just means their hearing impaired ears need more power for the headphone to reach comfortable listening levels. But that aside you want an amp that can supply enough voltage swing into so you have more headroom for loud parts and thats it.