[Noob Meister Jr]

if one amp is louder than another does that necessarily mean it will drive cans better? let's assume amps output impedance is zero. 

 

[KG Jag]

No.  Some cans (e.g. the Ultrasone Pro 750) can achieve high volume levels without having enough power to be properly driven.  You will goet high volume without the bass that it delivers when properly driven.

 

[manbear]

No. Unless an amplifier is distorting at volume levels you want, more power by itself will not be an improvement. It will just give you more volume. However, sound quality and power are two separate things. Some amps will sound better than others, and it's often the case that great sounding amps just happen to have a lot of power. But the power by itself is not what makes them better sounding. Low-powered amps can sound great too. So more power is not necessarily better, though in practice it often corresponds to better sound simply because a lot of quality amps are very powerful. 

 

[billybob_jcv]

I also think low volume can be the most easily identified symptom of an underpowered headphone. If you can't get the volume loud enough, that's a pretty good indication the headphones might have more potential waiting to be brought out. Of course, that's not always the case - sometimes increasing the volume just gives you an opportunity to clearly hear that you hate the headphones...

For most headphones, the impedance varies with frequency response. So, the amp might be able to meet the demand in one segment of the response, but run out of headroom in another part. I think that's one of the things that can happen when you change amps and see an improvement from your headphones - the new amp might now be able to meet the demands in more of the spectrum.

For example, here's the impedance vs frequency for the Sennheiser HD598, that is nominally rated at 50 Ohms:




Yeah - it is *nominally* 50 Ohms, but look at that peak at ~100 Hz - it is over 250 Ohms! So, what do you think happens when your music has a big kick drum or bass guitar beat right at ~100 Hz? Your amp is suddenly faced with a load it may or may not be able to handle.

 

[manbear]

That's a good point, Billybob. When faced with a changing load like that, an underpowered amp could do anything from just sounding a little muddy in the bass to clipping outright. If the distortion isn't really obvious, you might never notice it until you try a more powerful amp. 

 

[Noob Meister Jr]

 
Thanks guys, these are all great answers!

 
 But they don't directly answer my question (although they might indirectly).
 
Let me rephrase; is it possible for a certain amp to drive headphones better than another amp which has a higher maximum volume? assume the output impedance of the amps are zero. 
 
What do you think?
 
@Billybob: do you know where I can find one of those graphs for a 250 ohm DT880?

 

[billybob_jcv]

I'm not understanding what the maximum volume has to do with this at all. The maximum volume is set by the amp designer based on a somewhat arbitrary point where they feel providing more voltage is going to also provide too much noise. I don't think it represents the peak voltage the amp is capable of producing.

Are you trying to say that if one amp is louder when you turn the knob to "11", then that means it will do a better job with those headphones when the knob is at 6? I just don't think that's how it works.

That chart comes from http://www.headphone.com/ You can look there and see if they have the DT880. If they don't, you can also try http://www.innerfidelity.com, then look under Resources.

 

[manbear]

 
 
Let me rephrase; is it possible for a certain amp to drive headphones better than another amp which has a higher maximum volume? assume the output impedance of the amps are zero. 
 
What do you think?
 

Possible? Yes. But it would just be coincidence. If you have two amps, ordering them in terms of maximum volume has no necessary correlation with how you would order them in terms of sound quality. 

In practice, it is best for an amp to give your desired volume range somewhere between 10 and 2 o'clock on the volume control. Many amps have channel imbalance problems at low positions on the volume knob. Too much gain can also make the noise floor more likely to be audible. 

 

[Noob Meister Jr]

Are you trying to say that if one amp is louder when you turn the knob to "11", then that means it will do a better job with those headphones when the knob is at 6? I just don't think that's how it works

 
I'm not trying to say anything, but yes that was what i was asking.
 
Quote:

 I'm not understanding what the maximum volume has to do with this at all. The maximum volume is set by the amp designer based on a somewhat arbitrary point where they feel providing more voltage is going to also provide too much noise. I don't think it represents the peak voltage the amp is capable of producing.

 
This is the answer! Thanks!
 
Quote:

 That chart comes from http://www.headphone.com/ You can look there and see if they have the DT880. If they don't, you can also try http://www.innerfidelity.com, then look under Resources.

Thanks.

 

[Noob Meister Jr]

 
Possible? Yes. But it would just be coincidence. If you have two amps, ordering them in terms of maximum volume has no necessary correlation with how you would order them in terms of sound quality. 

In practice, it is best for an amp to give your desired volume range somewhere between 10 and 2 o'clock on the volume control. Many amps have channel imbalance problems at low positions on the volume knob. Too much gain can also make the noise floor more likely to be audible. 

this is a great answer too; thanks