[Dburns865]

Hello everyone! I was just wondering what price point, quality, impedance, ext. do your headphones need to be to benefit from an amp? I just ordered some V-moda M-80s, which are my first decent set. I'd like to get into the amp game beyond my homemade Cmoy and E5 but I don't want to get one if it wont really do anything. 

 

[roob]

Kind of depends on what output you already have... I see those are rated at 28.5 Ohms. I have a pair of Audio Techinca ESW9 at 32 Ohms, plays fine through an iPod Nano 5G unamped, but with my Sanza Clip they benefit from amplification. But I only knew that because I've heard the difference...
 
Anyway, doubt you need amplification for those.

 

[Papander]

You don't need amp with those.

 

[obobskivich]

It depends on a few factors:
 
- Sensitivity 
- Impedance 
- What you already own
 
Depending on the answer to #3, then you worry about 1 and 2 (even an iPod has an amplifier in it) when considering additional hardware. The majority of headphones do not require any substantial amount of power and do not present overly complex loads (flat impedance and high sensitivity is not uncommon). Simply looking at Znom though does not give you the entire picture. 
 
 
 

 

[Dburns865]

Thanks for the info guys. For future reference as I get better headphones over time, what are the factors that require amplifiers and generally at what price point do you start hitting them? When you do, should you start with cheaper ones like Cmoy or are those fairly useless?

I see you mentioned sensitivity and impedance. How do those help you determine that you'd need an amp to get the full potential out of your headphones?
 

 

[DevilDog]

There's not a price point where you need an amp. It's all up to you. Some headphones really do need an amp, some don't, that's the sensitivity and impedance issue.
Cmoys aren't useless, but they are limited. I would say it's best to go for the most you can afford, it will save you upgrading later.
 

 

[proton007]

From what I know, it depends on the source power. Most amps tell you how much power they can deliver at a particular impedance. To reach a certain SPL, if your headphone needs more power than the source can deliver, you need an amp.
The problem though, is that a lot of companies do not tell the power of the source. For example the iPod/iPhone does not have any published specs related to the power output.

 

[Eric_C]

Correct me if I'm off the mark here, but the basic ideas behind an amp are to:
- Amplify
- Without distortion
 
Yes? Tech specs aside, that's what a well-designed amp achieves?

 

[proton007]

 
Quote:

Correct me if I'm off the mark here, but the basic ideas behind an amp are to:
- Amplify
- Without distortion
 
Yes? Tech specs aside, that's what a well-designed amp achieves?

 
Of course. 
Hence you just need to check if the signal lacks power for your current driver. If yes, an amp is needed.

 

[obobskivich]

Yepyep. 
 
And +1 to the iPod thing. 
Quote:

Correct me if I'm off the mark here, but the basic ideas behind an amp are to:
- Amplify
- Without distortion
 
Yes? Tech specs aside, that's what a well-designed amp achieves?

 
 

 

[Dburns865]

Okay, I think I am getting it a bit more. Thanks again for the help.

So from what I found, generally you'll get 100 ohm max output from your laptop. Does that mean any headphone rated below 100 ohms will sound no different with and without an amp?
 
Sorry for all the questions, I am pretty new to this

 

[obobskivich]

I don't think you're quite there yet. 
 
You do not get Ohms "out" of anything - the Ohm is the SI unit of resistance. And it is not some arbitrary "rating" (I hate seeing "Ohm Rating" bandied around like it determines how "easy" something is to drive). 
http://en.wikipedia.org/wiki/Ohm 
 
Like I said before:
 
- Sensitivity
- Impedance
- What you already own
 
Quote:

Okay, I think I am getting it a bit more. Thanks again for the help.

So from what I found, generally you'll get 100 ohm max output from your laptop. Does that mean any headphone rated below 100 ohms will sound no different with and without an amp?
 
Sorry for all the questions, I am pretty new to this

 
 

 

[proton007]

 
Quote:

Okay, I think I am getting it a bit more. Thanks again for the help.

So from what I found, generally you'll get 100 ohm max output from your laptop. Does that mean any headphone rated below 100 ohms will sound no different with and without an amp?
 
Sorry for all the questions, I am pretty new to this

 
 
I haven't really heard that. 
But here's what you'll need to know from the headphone specs:
1) Impedance
2) SPL/mW
 
Speakers work on AC, so to get a higher impedance speaker to the same AC peak-to-peak needs more current (V = IR). Higher peak-to-peak means higher volume.
If you connect a speaker with higher impedance to a power source that cannot deliver the required current, you either do not get loud enough, or you risk damaging internal circuitry with too high current (that doesn't happen though, most circuits nowadays are designed well).
 
So in layman terms, an amp will just give your AC signal this extra current to get to higher voltages, hence amplifying the signal. That is all an amp does as its primary function.
 

 

[obobskivich]

proton: wut? 
 
Higher impedance = higher volts; lower current. 
Lower impedance = lower volts; higher current. 
 
There's a reason 'stats are "current-less," and that orthos are "current hungry."
 
You cannot arbitrarily have "lots of" or even "extra" current, it's dictated by R and V (I = V/R). You get to pick V, the headphones pick R, and I is dependent. And then power = I*V. If you only need X watts based on sensitivity (which is dictated by the headphones), you will only use as much current as Ohm's Law dictates you will. If the amplifier can deliver >X then it will not go into current-limiting, clipping, etc. If it can deliver <X it will have a bad day. For many headphones, X is a very small value relative to what many amplifiers can do. 
 
I feel like I'm missing your point though...
 
 

 

[stv014]

Quote:

So from what I found, generally you'll get 100 ohm max output from your laptop. Does that mean any headphone rated below 100 ohms will sound no different with and without an amp?

 
No, it is by no means guaranteed that a low impedance headphone does not benefit from amplification. First, some lowish impedance headphones have poor sensitivity (AKG K70x, planar magnetics, etc.) and/or high reactance (Sennheiser HD5xx, balanced armature IEMs), second, low quality headphone outputs on various devices often have flaws that affect low impedance loads mainly, such as limited current output and high distortion with low impedance loads (e.g. many CMoys), high output impedance (quite common for sound cards and receivers), capacitor coupled outputs (e.g. small portable devices and some sound cards), and high absolute noise floor (computer onboard audio). High output impedance, in addition to altering the sound of headphones, also reduces the maximum power into a low impedance load. For example, I have onboard audio with 77 Ohm output impedance, and a sound card with 100 Ohm output impedance; with these devices, a 32 Ohm or 250 Ohm headphone is powered about equally, but the latter benefits from a higher damping factor.