[lnvisible]

I really apologize fir this sad question, but I keep hearing talk about amped headphones and stuff, and came in this sub forum to ask the question. I don't even know what they look like, cause all the pics I have seen on them have been covered up since they have a source ontop.

So, what exactly are they, and what purpose do they serve?

I would think it is something you plug your source and phones in to increase the volume, and includes an equalizer, since I have always wanted a FULL OUT portable equalizer.

My rig is in my sig, but I have a 1st Gen Zune 30GB for the source, and, mainly, use my UE Super.fi 5 EBs with it.

Can someone help me though please? Thanks. I would have looked this up on Google but all I'm getting is guitar and instrument amps.

 

[wantmyf1]

The simplest explanation of an amp is that it serves to make the signal from the source to the headphones stronger. You can find various bells & whistles on them, but that's what an amp does.

You'll find plenty of pictures and a lot of information in this thread: http://www.head-fi.org/forums/f105/r...mpared-214588/

Skylab did a great job with this.

 

[lnvisible]

Thanks for the answer, but what do you mean by stronger? Do you mean better clarity, higher highs, or what?

 

[bcpk]

It makes the signal, eh, bigger. Like multiplying the formula of a wave by a constant - the shape is the same but it's on a greater scale. Without this amplification you wouldn't be able to hear anything because the original sound wave is so small.

 

[Armaegis]

Certain headphones also require a little more power to drive them properly. Sure you'd still get sound out of them, but it'll be muddy and distorted.

 

[lnvisible]

Thanks again so far everyone for helping me. Some more questions though, last bit I promise:

1. How are portable amps powered? I would suppose by batteries since
they are portable amps
2. In Skylabs thread, he mentioned how all different types of sound performed, such as bass and treble? Does this mean the amps have equalizers? The main I got interested in amps was that I thought they actually provided a way to alter the music, and had a knobby or LCD equalizer on them?
3. Would they actually improve the performance of my Turbines and EBs enough to even buy an amp?

 

[Happy Camper]

Tough call for IEMS. They don't shine as much as a full sized set but will benefit some. Some amps will add crossfade and gain/bass boost but the different sounds you hear will be opamp dependent. Is it worth the cost for this improvement to IEMs IMO, no but I have one anyway. I don't usually sell something I buy unless bribed otherwise but my Grados do benefit from the amp enough to lug it around.

 

[deetwo]

What they actually do is act as a current amplifier (also known as a power amplifier, the reason for this name is simply because P=I^2 * R).

At the output of your audio device for all frequencies there is a voltage associated with them. You can think of this relative voltage for the frequencies as the relative loudness of the spectrum (say ratio of bass to treble to highs).

Some headphones have a high input impedance/resistance (or load). You can think of the load as the amount of current required to drive the load to a high enough voltage to provide a loud enough sound (remember V=IR, where V is the voltage, I is current, and R is resistance).

In a simpler analogy think of a watermill. Tiny IEMs are a smaller watermill, big cans would be a heavier and larger watermill. The waterflow is exactly the same as how current would work for electronics. You require more current/electron flow to push the watermill to rotate at the same rate. Likewise, for headphones with higher impedance, more current is required to produce the same 'loudness'.

Ideally, an amp should retain the exact same voltage output, while providing a larger current. If you try to draw more current than your amp can provide it will start to 'clip' the voltage output. Say for a sinusoid wave with fixed amplitude would start to look more like a triangular wave. This leads to distortion.

 

[Gbjerke]

You could've saved so much time by just searching what is an amp. I'm getting kind of tired of these questions, as you don't even need to search ehadfi, u can search google.

 

[Currawong]

The problem with searching is, the portable market has changed considerably in the last year. As DAPs improved, so did their built-in amps, if you were using IEMs that is. The first time I tried one, I found it useless to use with IEMs for the most part, only boosting the bass. However, some newer IEMs, such as Westones and the very expensive JH-13s are extremely sensitive, and have less hiss with a good amp. Also, the newer amps have digital volume controls which are much more precise than regular volume pots.

However, some people were using portable amps with full-sized headphones, which isn't ideal, but I wont get into that.

Importantly though, the reason for using a better amp of any kind with headphones (or speakers) is that they are better at delivering what is a VERY rapidly changing signal.

 

[Alpha 1 Omega]

my thoughts on amps amps provide more power to headphones for more volume before noise and to compensate for power hungry headphones other that stock in box headphones.

 

[shigzeo]

I hope it will be helpful. My review of the ALO Rx tries its best to describe how hard to drive earphones (and not so hard ones) change when driven with the help of a GOOD amp. As you will see, especially balanced armature earphones are hard to drive to 0 decibels (frequency response) and a good amp which can reach low in impedance will really help.

Not all amps are geared to drive low ohm headphones, or high ohm headphones. Nor can all amps drive the crazy swings of a balanced armature earphone. Some which do, hiss like mad, some do not. There are so many and they are confusing. good luck.

 

[wantmyf1]

Thanks again so far everyone for helping me. Some more questions though, last bit I promise:

1. How are portable amps powered? I would suppose by batteries since
they are portable amps
Yes, an amp that is truly portable, not just small, is battery powered. Some have built in batteries others take ordinary batteries you buy in any department store

2. In Skylabs thread, he mentioned how all different types of sound performed, such as bass and treble? Does this mean the amps have equalizers? The main I got interested in amps was that I thought they actually provided a way to alter the music, and had a knobby or LCD equalizer on them?
Perhaps some do have an equalizer on them. In my searching I've never seen one, but one may exist. But even iF an eq is built in it's job is separate from that of the amp. Pretty much any component you put between the source and your phones will have an effect on the signal. It's just the effect of putting a signal through transisters. Perhaps one part of the frequency spectrum gets a little more of a boost than others. Usually though there is only one sound tweaking option on an amp with no DAC or EQ and that's bass boost. Though I have a C&C XO amp that offers 7 (I think) sound options. I don't use any of them.

3. Would they actually improve the performance of my Turbines and EBs enough to even buy an amp?
It's hard to say as I have never used either of those phones. Two headphone specifications, that are usually displayed on the box are OHM and Sensitivity. These have to be used in conjunction. Typically the higher the OHM's the more resistance in the phones and the harder they will be to drive. However the higher the sensitivity the easier they are to drive. High OHM & low sensitivity means a phone will be hard to drive. Low OHM & High sensitivity the easier they will be to drive.
And when it comes to headphones size really doesn't matter. I have a pair of Yuin PK1's that are buds and very small and they are 150 OHM and hard to drive & I have a pair of GMP 8.35D's (these are full size) that are 32 OHM and easy to drive.

 

[marcleonti]

Quote:

Originally Posted by wantmyf1 /img/forum/go_quote.gif Two headphone specifications, that are usually displayed on the box are OHM and Sensitivity. These have to be used in conjunction. Typically the higher the OHM's the more resistance in the phones and the harder they will be to drive. However the higher the sensitivity the easier they are to drive. High OHM & low sensitivity means a phone will be hard to drive. Low OHM & High sensitivity the easier they will be to drive.

What is the range usually found for ohms of resistance? What is considered to be low, midrange, and high? Also, what is the typical range for sensitivity, low mid, & high? I understand the concept, but I don't know what numbers would indicate easy to drive or hard to drive. Finally, do these numbers (resistance and sensitivity) have any indication if a particular headphone is prone to hum or hiss when amplified?

 

[marcleonti]

Quote:

Originally Posted by wantmyf1 /img/forum/go_quote.gif Typically the higher the OHM's the more resistance in the phones and the harder they will be to drive. However the higher the sensitivity the easier they are to drive. High OHM & low sensitivity means a phone will be hard to drive. Low OHM & High sensitivity the easier they will be to drive.

One more thing. Based on the info you provided, it appears resistance and sensitivity can work together or even counteract each other. It seems logical to assume that a low ohm, low sensitivity headphone can have the same degree of difficulty to drive as a high ohm, high sensitivity headphone. Is this correct, and if so, which is better?