# What does an amp do?



## Slivortal

COMPLETE NOOB here, and sorry for asking what must seem to you all such a stupid question.  I was looking for some kind of intro post that would help me out, but I didn't see any.
   
  My question is simply, "What does an amp do?"  I guess the simple answer to this question is that it would amplify sound.  But to me, this sounds like it simply allows you to reach higher volumes with the same equipment.  However, as someone who likes lower volumes I don't quite see the point.  And as most audiophiles recommend amps (including some who I hope don't like to blast their music), I feel that it must not "just" make the source louder - it must somehow increase the quality of the sound coming from the source (which seems strange to me, as you can't increase quality of a source, can you?)
   
  I must be missing something crucial here - can anyone help me out?


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## bowei006

Quote: 





slivortal said:


> COMPLETE NOOB here, and sorry for asking what must seem to you all such a stupid question.  I was looking for some kind of intro post that would help me out, but I didn't see any.
> 
> My question is simply, "What does an amp do?"  I guess the simple answer to this question is that it would amplify sound.  But to me, this sounds like it simply allows you to reach higher volumes with the same equipment.  However, as someone who likes lower volumes I don't quite see the point.  And as most audiophiles recommend amps (including some who I hope don't like to blast their music), I feel that it must not "just" make the source louder - it must somehow increase the quality of the sound coming from the source (which seems strange to me, as you can't increase quality of a source, can you?)
> 
> I must be missing something crucial here - can anyone help me out?


 
  They provide tonality and other technicaly things. If you are able to bypass the amp on your device like an iPod with an LOD, you can use an amp like a Pico or E11 to provide you with better sound! Amps also have technical features and objectivelly are different from each other. You can measure them and get technical results and measurements back that are generally much better than amps found in regular devices(if you use amps that are for headphones and are known to be good).. Then we have subjectivity and how each amp sounds a bit different and how it adds warmth or other features that a user might like or prefer.


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## Slivortal

bowei006 said:


> They provide tonality and other technicaly things. If you are able to bypass the amp on your device like an iPod with an LOD, you can use an amp like a Pico or E11 to provide you with better sound! Amps also have technical features and objectivelly are different from each other. You can measure them and get technical results and measurements back that are generally much better than amps found in regular devices(if you use amps that are for headphones and are known to be good).. Then we have subjectivity and how each amp sounds a bit different and how it adds warmth or other features that a user might like or prefer.




So an amp actually bypasses the native amps in a system? Just by connecting in a headphone jack? I'm not quite sure I understand... And if the amps add artificial qualities, doesn't that take away from the perfect unadulterated sound most audiophiles seek?

Thanks for the help ~


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## bowei006

Quote: 





slivortal said:


> So an amp actually bypasses the native amps in a system? Just by connecting in a headphone jack? I'm not quite sure I understand... And if the amps add artificial qualities, doesn't that take away from the perfect unadulterated sound most audiophiles seek?
> Thanks for the help ~


 
  No, I was referring to the iPod. If there is already an amp in the system then it will just add to it. With the iPod, if you use an LOD, you can bypass the amp that 's already in there.
   
  That's a huge discussion right now but no. Everything can be neutral or accurate but these qualities are usually small and add flavors to that sound. AT the price range of normal people it doesn't matter as it costs quite some money to get to that top sound. And amps to be used for that. We are just using amps that are high quality and "good" but that emit special qualities...that is sometimes very hard to tell apart. IT's hard to explain.


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## Slivortal

Quote: 





bowei006 said:


> No, I was referring to the iPod. If there is already an amp in the system then it will just add to it. With the iPod, if you use an LOD, you can bypass the amp that 's already in there.
> 
> That's a huge discussion right now but no. Everything can be neutral or accurate but these qualities are usually small and add flavors to that sound. AT the price range of normal people it doesn't matter as it costs quite some money to get to that top sound. And amps to be used for that. We are just using amps that are high quality and "good" but that emit special qualities...that is sometimes very hard to tell apart. IT's hard to explain.


 
  So, when it comes down to it, amps are basically like seasonings for headphones (excuse my low-level analogy)?  Yet I always here certain headphones are "better amped" - is that just because the headphones usually don't play at a high enough volume, or is it because they need the "seasoning" more than others?


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## Swimsonny

A LOD is a line out dock.
  Here is a picture example of an iPod Nano with an Amp and LOD connecting them.
   

  What we have here is my iPod Nano 4G connected with a Crossroads ED LOD to a Hippo cricri amp and some Vsonic GR07 IEMs.
  The LOD is that black cable thing connecting them. On one end (that goes into the amp) is a 3.55 jack and on the other end that goes into the iDevice is the pin connector like what you use to charge it.


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## Swimsonny

Dunno what happened here.


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## Swimsonny

Dunno what happened here!


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## Swimsonny

Dunno what happened here!


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## Swimsonny

Dunno what happened here!


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## Mutnat

Bear in mind also that some headphones, especially "audiophile" type headphones, can be very difficult to drive.  That is, they may require much more power than a typical portable source device (iPod, Sansa Clip, etc.) can provide, to drive the headphones even at reasonable volume levels.  So that's definitely one case where an external amp is pretty much required.
   
  As others have said, if you can bypass the amp on your device using a built-in line out, or an LOD (line out dock--they attach to your player's docking port and extract an analog signal from the device's DAC, before it would have gone through the device's headphone amp), then you can also get a much higher quality sound in many cases, even if your headphones are easier to drive.


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## paconavarro

As they explained an amp will improve the quality of the music, but why? mainly because the headphone is a moving diaphragm driven by a magnet and a coil and they have mass and mass responds to inertia and acceleration, so when you feed enough power to the coil in the driver, the dynamic (response) of the movement becomes more accurate making the sound reproduction better. 
  Its something like filling your gas tank with a 70 octane fuel in your car, the performance will be inferior compared to a 89 octane fuel. 
   
  Following this logic brands create headphones with higher impedance like 300 and 600Ohms so the coil is lighter and with less wire turns making it respond faster to the signals, but that requires more power in the line, thats when you need an amp.  This applies to all kind of impedance, no matter how easy to drive your headphone is, it will always be good to amplify it. 
   
  Some very sensitive IEMs tend to reveal channel imbalance (not present only in digital volume control and very low in some very high quality amps and) and background noise specially when playing music at very low levels.  If you want to upgrade your listening experience the first step and maybe the most important after changing or upgrading headphones is to get an amp.


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## Lukien

It is mentioned here that amp improves control of the sound produced by the headphones (drivers)
http://www.head-fi.org/t/408224/amps-for-dummies-what-does-an-amp-do
 And it is mentioned in this thread that amp makes the dynamic (response) of the movement of the driver more accurate and hence making the sound reproduction better. 
  
 From these 2 explanations, could i say that amps emphasize the strengths and weaknesses of the headphones?  Since it makes the sound more accurate.  For example, a headphone with good bass would have even more thumping bass when used with an amp, a headphone with clear mids would have even more cleaer mids, while a headphone with recessed mids overshadowed by its bass would well, make its bass totally overblown when connected to an amp.
  
 Just a thought, i'm new to amps too.


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## tibbsiren

then you can also get a much higher quality sound in many cases, even if your headphones are easier to drive.


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## Mooses9

Depending on the amp you have the amp can have operational amps that project a certain type of sound, along with high grade capacitors and onboard circuitry giving your headphones or iem a amplified sound.

However a good amp will be transparent meaning it only gives you high grade sound quality but doesnt color or effect any of the low,mid or high frequencies. I wouldnt say even realy good amps might yeild some coloring to the sound but very little. The ideal is to get as close to transparent as possible.

Along thing amps do is allow for a larger volume swing. Meaning in a simple form louder sound. Amplifiers might come with adjustment gains like high medium and low. Depending on the sensitivity of the head or iem you can adjust the gain to have a better volume pot.

I think the most important thing a amp does is provide power. More power gives you the ability to run multiple iem or headphones without any problems.

Something else to take into consideration with amps are interconnects and line outs if using a ipod. Depending on the type of cable used in cobjunction with the amp will draw a cleaner signal from the source to the amp then amp to the headphone. A cleaner signal might yeild no floor noise,pitch black imaging, and overall what you would expect from a cleaner signal better sound.


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## ProtegeManiac

bowei006 said:


> They provide tonality and other technicaly things.


 
  


slivortal said:


> So, when it comes down to it, amps are basically like seasonings for headphones (excuse my low-level analogy)? Yet I always here certain headphones are "better amped" - is that just because the headphones usually don't play at a high enough volume, or is it because they need the "seasoning" more than others?


 
  
 Technically speaking, the job of an _amp_ is to _amp_lify the sound. Amplifying means, in very basic terms,_ making the signal stronger _- with higher voltage and current for example. Amplifying does not include changing the tonality of the signal. If it changes the tone of the signal, there are other details in its "technicaly things."
  
 1) If the amp is deliberately changing the signal, it has an EQ built into it by design. It can be something like bass boost, or deliberately designing an amp using tubes for that oft-mentioned "tube sound" (when technically tube amps, if the circuit is done a certain way, won't be too far from the transparency of transistor-based designs - just with different maintenance requirements).
  
 2) The amp can be a better amp than, say, the portable player or any multi-purpose device like a tablet. It could be using an integrated chip that has both DAC and amp in it, running off a 7.4v Li-Po battery that also runs in worst case scenario a quad-core processor and a Tegra GPU designed for mass-market use and SQ far down the list. At the other end of the 3.5mm jack, you have earphones designed with low impedance and high sensitivity to squeeze as much volume as possible, which generally makes people think it sounds "better," but some designs might actually sound more transparent but require more current than the aforementioned integrated chip sharing its battery with a screen and essentially a small computer. Ditto headphones that have higher impedance, but also demand more current, or high impedance headphones (100ohm+) that may require more voltage.*

 So assuming it can send a quality signal to that amp, either through a line-out signal or streaming digital audio to a DAC (which may be built into the same box with the amp), then the amp is getting the kind of input signal that it can _amp_lify in order to better run a given headphone. Note that given the wide range of headphone impedance vs speakers that usually go from 8ohm to 4ohm, there are a lot more headphone amps that will do better with a few headphones than others.
  
 That said, instead of "seasonings," it may be more accurate to use as an analogy using the right kind of amp for the right kind of headphone the same way you would use the right kind of vehicle and the right kind of engine for winning a given type of race. You don't mount a 9,000rpm over-square 3.5L V12 with four turbos into an SUV that needs instant torque for rolling its wheels and getting it over a rock as big as it is (of course, a smallblock 351cu in Chevy V8 can power a sports car through a road race, partially because it tends to put less stress on the block than the high-rev V12, but that Corvette engine still isn't exactly the same V8 you'd find in 4x4 magazine).
  
  
  
  
  
  
_*Note that my iPad can get my 300ohm, 97db/1mW sensitivity HD600 loud at over 60% of the volume setting, and the SQ is actually decent, so while my amplifier can do a better job, during power outages (frequent during strong typhoons here), it's enough to wait out the time between the storm not making a racket on my tin roof and for power company teams to get my power back._


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## jjvvcckk

learned a lot here, Nice thread


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