headphone amps?

[Jon_Logan]

A) It's not a question about having the word on a product. It's a matter of making a specific product for headphones.

so what is different about a "headphone amp" exactly? It's an amplifier. You hope that it has a low output impedance so that it is load invariant. Period. Unless you want different load impedances to color the sound in different ways. I wouldn't call that a design goal.

B) If you short of remove the resistors that are meant to lower the wattage from the internal amp, then you would be sending 50 watts, 80 watts, 100 watts - full amplifier power - to your headphones and immediately vaporizing the voice coils.

Wrong.
There is no Wattage sent to the load (headphone/speaker). Dissipation, expressed in Watts is developed across the load. The amplifier is (should be) a voltage source. Yes, there can be more voltage available in an amp designed to drive speakers, but how much signal you throw at your headphones is up to you. There is no intrinsic danger with connecting to a power amp that was intended for speakers.

These 2 reasons alone are exactly the reasons why having a dedicated headphone amplifier a better choice than not. But in the end some people will prefer it, others won't. I believe that if headphone listening is your thing then you will dedicate yourself to getting the best equipment you can, much in the same way if listening to big speakers is your thing then you will purchase the best equipment you can for getting the best sound out of your big speakers.

Since the two points you brought up aren't correct, we still don't have a reason that a "headphone amp" is necessary. It's an amp. period. I will give you one possible reason why a so called "headphone amp" might have an improved listening experience. That one reason would be noise floor. If you're working with a certain dynamic range, and you don't need to be that loud, you can set your system gain lower, making the noise floor quieter.

But, that will vary from design to design. Some high gain amps are very quiet (wide dynamic range) and some low gain amps are noisy. It just depends.

 

[JimmyNeutron]

so what is different about a "headphone amp" exactly? It's an amplifier. You hope that it has a low output impedance so that it is load invariant. Period. Unless you want different load impedances to color the sound in different ways. I wouldn't call that a design goal.

Wrong.
There is no Wattage sent to the load (headphone/speaker). Dissipation, expressed in Watts is developed across the load. The amplifier is (should be) a voltage source. Yes, there can be more voltage available in an amp designed to drive speakers, but how much signal you throw at your headphones is up to you. There is no intrinsic danger with connecting to a power amp that was intended for speakers.



Since the two points you brought up aren't correct, we still don't have a reason that a "headphone amp" is necessary. It's an amp. period. I will give you one possible reason why a so called "headphone amp" might have an improved listening experience. That one reason would be noise floor. If you're working with a certain dynamic range, and you don't need to be that loud, you can set your system gain lower, making the noise floor quieter.

But, that will vary from design to design. Some high gain amps are very quiet (wide dynamic range) and some low gain amps are noisy. It just depends.

For starters, a headphone amp is designed to drive specific impedance as it's nominal range - specifically 8 ohms all the way up to 1600 ohms. A normal power amplifier is designed to drive a much smaller load, typically 2 to 16 ohms tops. A normal power amplifier also has other qualities like hi-current capability, slew factor, etc designed for driving larger speakers. How much of an effect these other power amplifier designs have on a set of headphones is debatable. But if you check out some of the threads over at Head-fi about amps and headphones it may make a bit more sense. I'm no expert in the field of headphones and amplifiers, and I've just begun to get into the headphone/amp/DAC area. I learned a lot from those guys over there. The 2 points I've made earlier are points that are better answered from the headphone pro like over at Head-fi. I've also recently bought a small portable headphone amplifier for my iPod just because of what I've learned thru them, and guess what? The improvement in sound ( not just volume but soundstaging, bottom end, vocals, etc ) are all profound. I now will never go back to listening to my iPod without an amp. For years I've listened to my headphones through my receiver, pre amp, and straight from my iPod. But sense I've purchased my dedicated amps I can clearly hear the difference. It's not placebo, it's a difference that unless you actually audition a good dedicated amp you just don't know what you're missing. Headphone amps are relatively inexpensive. It may be a nice income tax present to yourself to buy one.

Enjoy

Jimmy

 

[Jon_Logan]

For starters, a headphone amp is designed to drive specific impedance as it's nominal range - specifically 8 ohms all the way up to 1600 ohms. A normal power amplifier is designed to drive a much smaller load, typically 2 to 16 ohms tops.

Um, you don't really mean to say that do you? "16 ohms tops"? If you do, you're not really understanding amplifiers. You can drive an open load with a "normal amp".

A normal power amplifier also has other qualities like hi-current capability, slew factor, etc designed for driving larger speakers. How much of an effect these other power amplifier designs have on a set of headphones is debatable.

These "normal amp" specs would apply to headphones as well (God, I hope). Only a high current capable amp could maintain these specs into less than 8 ohm loads.

But if you check out some of the threads over at Head-fi about amps and headphones it may make a bit more sense. I'm no expert in the field of headphones and amplifiers, and I've just begun to get into the headphone/amp/DAC area. I learned a lot from those guys over there.

IMO, just because there's other threads supporting questionable science doesn't make it true. This is the internet. For every fact, there's many anti-facts, for lack of a better word.

The 2 points I've made earlier are points that are better answered from the headphone pro like over at Head-fi. I've also recently bought a small portable headphone amplifier for my iPod just because of what I've learned thru them, and guess what? The improvement in sound ( not just volume but soundstaging, bottom end, vocals, etc ) are all profound. I now will never go back to listening to my iPod without an amp. For years I've listened to my headphones through my receiver, pre amp, and straight from my iPod. But sense I've purchased my dedicated amps I can clearly hear the difference.

That's nice to hear what your perception was.

It's not placebo, it's a difference that unless you actually audition a good dedicated amp you just don't know what you're missing.

:scratch2: I think best practices testing would sort that out.

Headphone amps are relatively inexpensive. It may be a nice income tax present to yourself to buy one.

See? ... that's what I was hoping for. Finally a reason that everybody would benefit from a "headphone amp"

 

[JimmyNeutron]

IMO, just because there's other threads supporting questionable science doesn't make it true. This is the internet. For every fact, there's many anti-facts, for lack of a better word.

Oh OK. I see. But YOU are telling the truth, just not anyone else. Whatever. Seems you've made your points.

Jimmy

 

[Jon_Logan]

Oh OK. I see. But YOU are telling the truth, just not anyone else. Whatever. Seems you've made your points.

Jimmy

I'd love there to be a factual reason for having headphone amps. But, I'd like the facts to be there before recommending that people buy these to gain an improvement. I would love for a listening test to show the improvement. I think we'd first have to agree that your test conditions was very prone to errors and bias.

I think most science based assumptions would say "No, headphone amps are unnecessary". I think the group that say they sound different/better might be the side that is eager to demonstrate that. Many people read these threads for advice. After reading the beginning of the thread and disagreeing with some of the beliefs, I'd think it a disservice to not give my honest impression of the subject. The headphone amp might be necessary for you to achieve the best sound. It might not be necessary for all looking for advice though.

 

[bOUddha]

Some people would simply study sheet music and tell you there's no scientifically substantiated difference between Mozart and Alice Cooper.

 

[Jon_Logan]

Headphone amps

is it physics or is it art?

 

[JimmyNeutron]

Some people would simply study sheet music and tell you there's no scientifically substantiated difference between Mozart and Alice Cooper.

Aaahhhh. But who did the teaching? And why believe him? For everything that is taught by someone you can find someone else teaching the opposite. LOL!!!

 

[bOUddha]

Jon L-

To you, they are just schematics, numbers and electrical nomenclature on a page just like sheet music.

Bottom line, until you've heard what thousands of others have heard and testified to your opinion is worth exactly the same as the ether that carried it here. I also realize that having formed your opinion from the spec sheet, your hide bound viewpoint would preclude any attempt at objectivity should you even try one for yourself.

 

[BmWr75]

I'd love there to be a factual reason for having headphone amps. But, I'd like the facts to be there before recommending that people buy these to gain an improvement. I would love for a listening test to show the improvement. I think we'd first have to agree that your test conditions was very prone to errors and bias.

I think most science based assumptions would say "No, headphone amps are unnecessary". I think the group that say they sound different/better might be the side that is eager to demonstrate that. Many people read these threads for advice. After reading the beginning of the thread and disagreeing with some of the beliefs, I'd think it a disservice to not give my honest impression of the subject. The headphone amp might be necessary for you to achieve the best sound. It might not be necessary for all looking for advice though.

I don't have any facts about why a dedicated headphone amp should sound better than the headphone jack on a receiver. But I have got ears and can say that none of the HP outputs of vintage receivers or amps I own sound anywhere near as good as the three headphone amps I own.

 

[JBL GUY]

Headphone amps

is it physics or is it art?

It is the art of ignoring physics.

Threads like this would be great if some of the posts did not ignore
basic electronic theory and post a lot of incorrect information and use incorrect terms.

Just a few things.

It may be that "Some, Certain" headphones will sound "Better" when driven from an amplifier with a high out put impedance. That is the designer of the headphones does not want the amplifier to have "Tight" control over the driver diaphragm. In this case the diaphragm would be free to be more influenced by its own electro-mechanical properties.

This is operating headphones with an amplifier that exhibits a low damping factor with said headphones.

Other headphones may in fact sound "Better" when driven by an amplifier with a very low output impedance. This would cause the amplifier to have much greater control over the movement of the driver diaphragm.

This is operating headphones with an amplifier that exhibits a high damping factor.

Using headphones with an amplifier that drives headphones via dropping resistors (Lower damping factor) may in fact not sound as good because those headphones may need to be driven by an amplifier with a high damping factor.

Notice my use of the word "May".

I have used the terms "Sound Good" and "Not sound as good". These are entirety subjective terms. What is good or bad to one person may not be the same for another person.

I have read on this thread comments about dropping resistors not being able to make up voltage swing. Resistors are passive they can not make up for anything. Just to be clear I believe what the poster meant is that if the value of the resistor is to large then based on the maximum voltage swing of the amplifier, the voltage drop across the resistors will be to great and the resulting voltage may not be sufficient to drive the headphones in question.

For starters, a headphone amp is designed to drive specific impedance as it's nominal range - specifically 8 ohms all the way up to 1600 ohms. A normal power amplifier is designed to drive a much smaller load, typically 2 to 16 ohms tops.

I also saw this posted. This is incorrect use of terminology.

Actually a 2 ohm load is a larger load on an amplifier than a 1600 ohm load.
That is because a 2 ohm load will draw more current (See Ohms Law) than a 1600 Ohm load given the same voltage.

A 100 watt light bulb is a larger load than a 25 watt light bulb because it draws more power.

So a standard amplifier is actually designed to drive a much higher load as referenced in the above post.

I believe the poster is confusing the terms "Load" and "Impedance"
A particular headphone amplifier may be designed with a higher output impedance, to better drive a certain headphone. Hmm sounds like low damping factor as I alluded to above.

I am not making this point to put anyone down. Just if you are trying to make your case, using technical terms at least get the use and terminology correct.


Understand that for the purpose of this post I am not taking sides.

But for those of you that claim a headphone amp "Sounds Better", I have a simple question.

Since the headphones respond to the signal sent to them...

How is the signal changed by the headphone amplifier?

If the sound is different, then the signal MUST be changed in some way.

How is it changed?

I will give you that a small low power amplifier "May" have a lower noise floor.

And since the power levels are lower, it may be easier to implement a class "A" amplifier design. Smaller idle currents and such.

And as I mentioned some headphones may play better when used with a amplifier with a high damping factor relative to the headphones impedance and some may play better with an amplifier with a lower damping factor relative to the headphones impedance. And series dropping resistors will have an effect on the damping factor.

That said, again I ask how is the output waveform from a headphone amplifier different than the waveform from a "Regular" amplifier.

And I mean comparing units with similar build quality, both using high quality components.

And since this debate is about hearing "What Sounds Better", can any of you headphone amplifier are better group explain "Noise Dithering" as it relates to certain digital playback formats.

I ask just to ascertain your level of understanding some of the processes by which we, with our ears, determine sound quality.

Again I am not trying to put anyone down. But to have fair and meaningful debate we all have to be on the same page with our understanding of the subject mater at hand...

Because everything that we hear/listen to is affected by psycho-acoustics.

So if you want to try to explain why headphones driven by headphone amplifiers sound better, you must first understand the mechanics and psycho-acoustics of the human hearing process.

Then one can make valid arguments one way or the other.

Again I am not taking sides in this debate. I would just like to see the quality and accuracy of the debate improved. Especially for those that read these posts,in an attempt to learn, but do not themselves post.

BmWr75
I don't have any facts about why a dedicated headphone amp should sound better than the headphone jack on a receiver. But I have got ears and can say that none of the HP outputs of vintage receivers or amps I own sound anywhere near as good as the three headphone amps I own.

Ok just saw your post...I am editing mine in MS Word and not refreshing the page.

I will give you that the headphone amplifiers sound better to you.

Tell me how they sound better. I am serious I would like to know.

What qualities and characteristics are different.

Because if we can discover something new and quantify and qualify it, then it can be used for the benefit of all.

It may help us to explain why and by knowing why may prevent one of use from purchasing a headphone/headphone amplifier combination that does not play well together.

For example we know that certain speakers that have an impedance that dips very low will not play well with certain current limited amplifiers.

So what say you....? Anyone?

 

[HypnoToad]

Years ago I remember it was the in thing to get a pair of budget headphones from say Akai, Pioneer etc and wire a headphone jack in parallel with the speaker outputs of your 3 in 1 stereo.

This would provide what we thought was extremely dynamic and also extremely loud sound. Not good for your hearing but they sure sounded good to us at the time.

 

[JBL GUY]

Years ago I remember it was the in thing to get a pair of budget headphones from say Akai, Pioneer etc and wire a headphone jack in parallel with the speaker outputs of your 3 in 1 stereo.

This would provide what we thought was extremely dynamic and also extremely loud sound. Not good for your hearing but they sure sounded good to us at the time.

You are bringing back memories...And making me feel old:yes:

I wish that I still had those old Sansui headphones...Probably not good by today's standards but I sure thought they sounded good wired directly to the speaker outputs.

I sure enjoyed the

 

[33&athird]

I am not making this point to put anyone down. Just if you are trying to make your case, using technical terms at least get the use and terminology correct.

Lord...I am realizing how much i've forgotten in a couple semesters since my last electronics class. I don't know, I need to read my books again, haven't thought about it in too long a time, being swamped with a lot of other school work (plus my current campus has no other courses to progress in, so i'm making up stock classes). I understand your points, and indeed, I may have mixed terminology, for all purposes, i'm bowing out of this one...in my experiance, my headphones sound better through a dedicated amp, right now I can't provide a adequate reason, I suppose...and personal testimony does not a point prove.

Anyway, i'm ducking out

 

[JBL GUY]

Lord...I am realizing how much i've forgotten in a couple semesters since my last electronics class. I don't know, I need to read my books again, haven't thought about it in too long a time, being swamped with a lot of other school work (plus my current campus has no other courses to progress in, so i'm making up stock classes). I understand your points, and indeed, I may have mixed terminology, for all purposes, i'm bowing out of this one...in my experiance, my headphones sound better through a dedicated amp, right now I can't provide a adequate reason, I suppose...and personal testimony does not a point prove.

Anyway, i'm ducking out

I

I do not doubt that your headphone amplifiers sound great.

Although I did not take a stand in my previous post, I have to tell you that I had to come up with a way to drive several pairs of headphones at the same time from a line level output. I have a pair of small amplified speakers. So I installed a headphone jack so I could run the output to a distribution block.

The speakers in this pair of speakers is rated at 3.2 Ohms per the stamp on the magnet. So the amplifier built into one of the speakers is definitely designed to drive a low impedance load.

Plugged my 300 Ohm headphones into the headphone jack connected the amplifier in the speaker and they sounded just great. I was really surprised at the great sound quality. I was not expecting much in the way of sound quality.

I am not going to mention the brand of headphone, I do not want to bias my results in terms of others expectations of a certain brand of headphone, but they are generally accepted as quality headphones here and on other forums.

I can not tell the number of the chip amps in the speaker because they have a heat sink glued on them.

Just as a test to "match the impedance" of the amplifier to the headphones I put a pair of 300 Ohm resistors in series with the output.

While it was not a drastic change in the sound quality, I could detect a slight change in the frequency response in the upper bass, lower midrange. It sounded more boomy and honky and the lower bass was not as tight or crisp.

The upper frequencies were not as well defined. I suspect that there might be some "Ringing" of the headphone driver since with the resistors it was effectively decoupled from the amplifier in terms of control. Also the introduction of the series resistors will have changed the Q of the circuit.

I would like to take time and run some tests in my sound chamber, but will not have time to do so for awhile.

Now understand the change was very subtle, but detectable.

I believe the high damping factor of the very low output impedance of the amplifier has a lot to do with the very tight, crisp and detailed sound quality, because the amplifier has very tight control of the headphone driver diaphragm.

I have only had time to listen to this one pair of headphones. It is entirely possibly that I may not have the same result with other headphones.

Your mileage may very:yes:

 

[Rex Aeterna]

@JBL guy

you are giving me worlds of information i do not know and thank you first of all. i enjoy learning and understanding this since listening to music and anything music is what i love.

now what i understand all this impedance matching is not really accurate since impedance consentingly changes within a certain frequency range. i know this is a fact for speakers but dose this imply for headphones as well?

i have hooked up my akg 240's to my sony mp3 player which is designed for headphones up to 55ohms but doesn't sound no where near as detailed when i have my akg's hooked up to my sansui receiver with output impedance of 680ohms(due to the resistor used from what i was told). is it cause there is a spike in impedance like speakers? i know the drivers are no where near as big as speakers but does that matter when it comes to consent impedance shifts?

 

[Cadillac Kid]

Tell me how they sound better. I am serious I would like to know.

Comparing the headphone out on my McIntosh C220 to my Lehmann Black Cube Linear, the difference was not subtle.

Using the Sennheiser HD800s- the Lehmann is faster, clearer, more detailed and the bass is better focused. Music comes from a blackness with better soundstage and is just plain more enjoyable.

The Lehmann really brought the HD800s to a new level.

The McIntosh C220 has an OpAmp headphone out that really could not handle the Senns, so in my case a separate headphone amp has an obvious benefit.

 

[Rex Aeterna]

Comparing the headphone out on my McIntosh C220 to my Lehmann Black Cube Linear, the difference was not subtle.

Using the Sennheiser HD800s- the Lehmann is faster, clearer, more detailed and the bass is better focused. Music comes from a blackness with better soundstage and is just plain more enjoyable.

The Lehmann really brought the HD800s to a new level.

The McIntosh C220 has an OpAmp headphone out that really could not handle the Senns, so in my case a separate headphone amp has an obvious benefit.

i would assume cause your mcintosh only has output impedance of 250ohms where nomial impedance load is 300ohms of the senns from what i remember. the black cube is 300ohms@200mw. that should explain it most likely

 

[Permanent Waves]

Wow...lots of info in here I'll have to try to wade through when I get the chance. I am no technical guy (at least regarding technology) so I don't know how well I'll grasp it all anyway.

For me, I MUST conform my beliefs to what the empirical evidence dictates. So if it is indeed true that there is no valid scientific reason why the headphone outs on my various receivers/amps (and those of my friend's) should sound any less as good as my 3 external HA amps as I currently (but always somewhat tentatively) hold, well, then THEY DON'T. And I have to admit that whatever difference I thought I heard (or even still hear) was all due to the placebo/psycho-acoustic effect (I never did any blind testing between these outs and external HA amps for one thing), for this effect can exert a powerful perceptual influence on an individual EVEN IF that individual is already wary of its pervasive, yet false/misleading influence. This is how I try to work, I will not try to defy scientific law/fact with my mere personal experience (which is, of course, a VERY shoddy edifice for one to try to come to and support knowledge/beliefs about anything at all), much less what I wish to be true (in this case that I did not waste money on external HA)...that would be utterly foolish, to think I simply "know" better than what reality dictates; that my experience/perception is infallible and physical law/publicly verifiable/repeatable/testable/empirical evidence be dammed.

I'll say right now that one reason I have not bought any more expensive HA than I have is because I've always been wary as to whether or not they make a difference (as I said above) based on some facts I've read about them and various receiver/amp outs before (as well as my general overall skepticism about the value of higher than a certain reasonable level priced audio gear), even if impe (in my personal experience) they do seem to make a significant difference.

Thanks to all the dissenters itt: I love a good fact/logic based debate, especially if it has a reasonable conclusion for one side or the other (again, I have to go through these posts in detail before I can begin to decide). Nothing more satisfying to me than at least coming to a good approximation (if not a definitive conclusion) of the "truth" (lower case t of course).

 

[voltcontrol]

what are headphone amps mainly for? is it for if you don't have a receiver? I had never heard of them until I joined the forum so I am just wondering what they are and what not.

Perhaps the OP got more answer than he bargained for.

I abuse my soundcard as HP amp, rather like how it sounds.