[scuttle]

Quote:

But I also think that it's possible that some amps are designed with a pseudo EQ in mind. In which case, different amps with different EQ tweaks will sound different.

 
All amps have a sonic signature. But it's pretty trivial to duplicate said signature using EQ, so it isn't a good reason to buy a new amp if you have a decent one that isn't clipping with the transducer you are using.

 

[chewy4]

Quote:

 
But that's not just any particular amp.
 
That's a lot of low-end amps. And the Fiio E6 unfortunately falls into the same category. Need an example? Try the Digizoid ZO. Or better yet, try Fiio's E7, E11, E17, and the newly released E12. I have. They don't sound the same. Disregarding their bass boost switches, they still have undue colorations to the sound.
 
Seriously, not every amp has perfectly flat and accurate frequency response down to a fault. That's why the O2 is so popular. It's about the only amp under $200 that doesn't add or subtract anything from the original signal. It just makes it louder.
 
And also seriously, just because an amp has undue colorations (read: EQ) doesn't make it not worth having. Unless you have a headphone that is perfectly accurate (Stax?) using an amp with some EQ to "correct" the frequency response of the headphone is a perfectly acceptable practice.

How could you possibly expect an amp to do that unless it was engineered specifically for that pair of headphones? You'd be much better off just getting an equalizer so you could not only use the amp for more than one pair of headphones, but also be a lot more accurate and have the ability to adjust it.

 

[scuttle]

Quote:

 
But that's not just any particular amp.
 
That's a lot of low-end amps. And the Fiio E6 unfortunately falls into the same category. Need an example? Try the Digizoid ZO. Or better yet, try Fiio's E7, E11, E17, and the newly released E12. I have. They don't sound the same. Disregarding their bass boost switches, they still have undue colorations to the sound.
 
Seriously, not every amp has perfectly flat and accurate frequency response down to a fault. That's why the O2 is so popular. It's about the only amp under $200 that doesn't add or subtract anything from the original signal. It just makes it louder.

 
Ok: these are serious points that I would have agreed with not long ago, and I'll try to explain why they might be worth modifying a little.
 
1. The O2 is a neutral amp - and a very good one - but it's hardly the only one. If you read the designer's own blog then his tests show that the Sansa Clip+ has a very neutral signature - and so do the Fiio e5 and e7 which he also tests, although they don't have the O2's ability to drive really difficult fullsize cans. The 02, being designed to drive really tough cans, is not a true pocket amp, so it makes sense to consider other that are, at least when the O2's full power is not required. Which maybe it isn't in this case.
 
2. At the end of a day a neutral source used with neutral headphones may not be neutral for you. Why? Because your damn non-standardized ear cavity will interact with the headphones and (even more so) IEMs. In fact, if you want real neutrality then the only answer is to EQ - see the "Tuning headphones with pink noise" article on head-fi. If you are EQing anyway, I don't see that an utterly flat signature is that desirable, although I would stay from heavily bass boosted amps.
 
PS for Ultrabike: aren't cmoy amps  supposed to be for high impedance headphones? Is the U900's impedance that high???

 

[scuttle]

Quote:

How could you possibly expect an amp to do that unless it was engineered specifically for that pair of headphones? You'd be much better off just getting an equalizer so you could not only use the amp for more than one pair of headphones, but also be a lot more accurate and have the ability to adjust it.

 
Plus, almost every source people use these days has an equalizer built in. 99% of the listening done by people here has to be done on DAPs - and if a DAP doesn't have at least a 5 band EQ I'd ditch it - or using a computer as a source. I don't blame Biily-P in the least: there's a strong and very irrational "audiophile" mythology against using EQ and it's hard to escape something so pervasive.

 

[Bill-P]

Quote:

All amps have a sonic signature. But it's pretty trivial to duplicate said signature using EQ, so it isn't a good reason to buy a new amp if you have a decent one that isn't clipping with the transducer you are using.

 
It's still a good reason to buy one that has more power than needed, because the correct way to EQ is to reduce the volume of frequencies you don't want to boost, and thus you end up having to listen to your headphone "louder than necessary". Note: by this, I mean you have to increase volume, or everything that you EQ'ed down would sound tinny.
 
But EQ doesn't take away the characteristics of the headphone. You still need more power to increase volume. Since sound pressure level is measured using a logarithm function, it takes a lot more power to go up by just 1dB. Why do you think people need something as powerful as the Schiit Lyr?
 
Quote:

How could you possibly expect an amp to do that unless it was engineered specifically for that pair of headphones? You'd be much better off just getting an equalizer so you could not only use the amp for more than one pair of headphones, but also be a lot more accurate and have the ability to adjust it.

 
An amp can still "correct" the sound signature of the headphone by bring it closer to neutrality. It doesn't have to be perfect.
 
Quote:

Ok: these are serious points that I would have agreed with not long ago, and I'll try to explain why they might be worth modifying a little.
 
1. The O2 is a neutral amp - and a very good one - but it's hardly the only one. If you read the designer's own blog then his tests show that the Sansa Clip+ has a very neutral signature - and so do the Fiio e5 and e7 which he also tests, although they don't have the O2's ability to drive really difficult fullsize cans. The 02, being designed to drive really tough cans, is not a true pocket amp, so it makes sense to consider other that are, at least when the O2's full power is not required. Which maybe it isn't in this case.
 
2. At the end of a day a neutral source used with neutral headphones may not be neutral for you. Why? Because your damn non-standardized ear cavity will interact with the headphones and (even more so) IEMs. In fact, if you want real neutrality then the only answer is to EQ - see the "Tuning headphones with pink noise" article on head-fi. If you are EQing anyway, I don't see that an utterly flat signature is that desirable, although I would stay from heavily bass boosted amps.
 
PS for Ultrabike: aren't cmoy amps  supposed to be for high impedance headphones? Is the U900's impedance that high???

 
1) The author of the O2 measured the Fiio E5 to have 3.5dB deviation from 20Hz to 20KHz, which I'd argue is actually very audible. Similarly, the E7 was also measured by him to have a 1.5dB drop at 80Hz. Now... take an EQ and dial 80Hz down by 1.5dB, and let me know if you can't "hear" that. If you can, then obviously neither the E5 or E7 is "neutral" or "linear", right?
 
2) Exactly. Which is why a colored amp with EQ may sound neutral to one person, and a neutral amp (say, O2) may not sound neutral to another person. O2 is used as the benchmark here because it "measures" well. But if we have to rely on subjective experience for this one, then please tell me when you have found one person who has listened to a "better" amp than a E6... to not recommend an E6 owner to upgrade.
 
And headphone impedance is not the end of the story. Their sensitivity/efficiency rating also plays into power requirement as well. In fact, here's a chart:
http://www.head-fi.org/t/476345/headphone-sensitivity-power-requirements-compared

 

[ultrabike]

Quote:

PS for Ultrabike: aren't cmoy amps  supposed to be for high impedance headphones? Is the U900's impedance that high???

 
According to HeadRoom, the U900 is not a very high impedance headphone (about 40 to 50 ohms across the frequency range)
 
However, the cmoy has been reportedly shown lower distortion numbers on 15 and 150 ohms. It also seems to have lower crosstalk. In regards to ability to drive 33 ohms (U900 bulk park), the cmoy has been reported to be able to provide 121 mW vs the 59mW provided by the E6. Also, building your own cmoy may have some cool factor associated.
 
That said, the E6 is cheaper (2x), and smaller (more practical.) Both amps can recharge their internal battery, but the E6 does so through the USB port, while the cmoy requires a wall wart.
 
Obviously there are some convenience and portability trade-offs, but I think a cmoy might be a step up in performance vs. an E6 if using an U900. If the performance advantages translate into audible improvements, and portability is still acceptable, the cmoy might be an possible alternative depending on priorities.

 

[stv014]

Quote:

Originally Posted by Bill-P /img/forum/go_quote.gif
 
Similarly, the E7 was also measured by him to have a 1.5dB drop at 80Hz.

 
That is false information, the E7 was measured to have a +/- 0.1 dB frequency response between 20 Hz and 20 kHz using the analog input, and the USB input only changes that by adding a slight roll-off at the top end due to the DAC filtering (<1 dB at 20 kHz).
 
Quote:

Originally Posted by Bill-P /img/forum/go_quote.gif
 
Why do you think people need something as powerful as the Schiit Lyr?

 
Few people need something as powerful as the Schiit Lyr (mostly those with very inefficient planar magnetics), and those who have it are also often ones who believe that EQ (or any other digital processing) is evil and should never be used.

 

[stv014]

Quote:

Originally Posted by ultrabike /img/forum/go_quote.gif
 
However, the cmoy has been reportedly shown lower distortion numbers on 15 and 150 ohms. It also seems to have lower crosstalk. In regards to ability to drive 33 ohms (U900 bulk park), the cmoy has been reported to be able to provide 121 mW vs the 59mW provided by the E6. Also, building your own cmoy may have some cool factor associated

 
121 mW into 33 Ω is 85 mA peak current, and 170 mA peak ground current with both channels driven. That is an unusually powerful cMoy, is it that NJM4556 one with no gain ? Typical cMoys use lower current op amps, and often even weaker virtual grounds (like the TLE2426 that cannot output much more than 30 mA). If it is some other cMoy and the crosstalk was measured with RMAA, note that RMAA lies about crosstalk and consistently shows it to be 6 dB better than reality, in addition to the measurement often being unreliable because of ground loops in a sound card loopback setup.

 

[stv014]

Quote:

Originally Posted by Bill-P /img/forum/go_quote.gif
 
Or better yet, try Fiio's E7, E11, E17, and the newly released E12. I have. They don't sound the same. Disregarding their bass boost switches, they still have undue colorations to the sound.

 
The amplifiers in both the E7 and E11 were measured to have fairly flat frequency response, with <0.1 dB attenuation at 20 Hz and 20 kHz, and both also have less than 1 Ω output impedance. Other than the obviously rolled off E5, only the E6 has a ~0.7 dB roll-off at 20 Hz, that could indeed make an audible difference in an ABX test, but not a major "night and day" difference.
 
Regarding undue colorations to the sound, an important source of these has already been explained at one of the links posted above:
Quote:

Does this mean all amps sound the same in a normal install?

 
No. Richard Clark is very careful to say that amps usually do not sound the same in the real world. The gain setting of an amplifier can make huge differences in how an amplifier sounds, as can details like how crossovers or other filters are set. When played very loud (into clipping), the amplifier with more power will generally sound better than a lower powered amp.
Most people perceive slight differences in amplitude as quality differences rather than loudness. The louder component sounds “faster, more detailed, more full”, not just louder. This perceptual phenomenon is responsible for many people thinking they liked the sound of a component when really they just liked the way it was set up.

 

I changed amps in my system to another one with the same measured power and I hear a sound quality difference. Does this show that the test results are invalid?

 
No. Installing a new amplifier involves setting the gains and crossovers, and any slight change you make to those settings is going to affect how things sound.

Without careful level matching (by measurements, not by ear), subjective comparisons of amplifiers should be taken with more than just a grain of salt.

 

[streetdragon]

the only thing the E6 does is to boost the volume and change the eq sound.
the bass boost is not good either. it boosts all the way up to about 200hz from what i hear on it

 

[chewy4]

Quote:

 
An amp can still "correct" the sound signature of the headphone by bring it closer to neutrality. It doesn't have to be perfect.
 
 

Do you have any examples of amp/headphone combos that do this?

 

[tostaylo]

My first amp was the E17.  I liked it and enjoyed the treble, gain, and equalizer settings.  Next I purchased the E6 to save money and space.  To my ears I cannot tell a difference in sound quality on their neutral settings, although I have never done a proper DBT.  Honestly, I like the EQ settings on both amps better than neutral.  I use EQ settings in itunes and on the E6 depending on what genre I listen to. To my ears the Pro 900's benefit from a boost in the mid-range as they are already outstanding in the bass and treble departments.  My original question was posed to see if I am missing out on something by not spending more money.  It doesn't sound like I am, besides having an amp that is more aesthetically pleasing and solidly built.

 

[streetdragon]

Quote:

My first amp was the E17.  I liked it and enjoyed the treble, gain, and equalizer settings.  Next I purchased the E6 to save money and space.  To my ears I cannot tell a difference in sound quality on their neutral settings, although I have never done a proper DBT.  Honestly, I like the EQ settings on both amps better than neutral.  I use EQ settings in itunes and on the E6 depending on what genre I listen to. To my ears the Pro 900's benefit from a boost in the mid-range as they are already outstanding in the bass and treble departments.  My original question was posed to see if I am missing out on something by not spending more money.  It doesn't sound like I am, besides having an amp that is more aesthetically pleasing and solidly built.

you may want to try getting some eq software/apps and playing around with them. gives you much more flexibility and power over your sound.

 

[tostaylo]

Nice, can you recommend any for Mac?

 

[streetdragon]

Quote:

Nice, can you recommend any for Mac?

uhh.... not that i know off sorry. not used a mac before, hopefully someone can provide you with some suggestions