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post #1111 of 3453
Quote:
Originally Posted by miceblue View Post

This has been kind of bugging me for a while (not just to pick on you, but in general):

 

How does one define what transparent "sounds like"? The O2 was designed to "sound transparent", so how can one justify something "sounds more transparent" and how can one actually actually confirm this? The designer of the O2 says it's transparent, but how does he know? I have heard multiple people say a Leckerton amp sounds more detailed than the O2; does this mean it's more coloured than the O2?


The last part means nothing, unless it can be demonstrated in double blind tests. Even then, it has yet to be ascertained whether it's actually an increase of detail you'd be talking about, or just more treble (or whatever).

 

The reason amps can be 'transparent' (which is not the same as 'transparent sounding', which is total nonsense because nobody knows what that even means) is because amping a signal is a science. If an amp measures well, it will perform accordingly. If it measures worse, it will sound different. The problem is that some people may feel that it sounds 'better' when it technically performs worse. At that point all bets are off and even the most badly designed amp can be conceivably sold. Another problem with audio is that impressions can hardly be verified, so even the most objective listener will be exposed to his own subjective preferences when evaluating gear.

 

All of that does not take anything away from the fact that amping is a science and that scientifically and technically, you can build an amp that objectively performs as well as possible when it comes to sound quality. Contrary to popular belief on headfi, an amp is not able to do anything magical that goes beyond measurements. It can not magically alter the amount of detail that is heard beyond what measurements account for. It can not be made to sound warmer or colder beyond making adjustments to frequency response (which is undesirable and I don't personally know any amps that shoot for strange deviations but I'm sure they're out there) or accounting for impedance mismatches. Likewise for soundstage, etc. The mistake that is often made is that people seem to think an amp is a way to beautify the sound, while in fact all it's supposed to do is to carry out the technical task of amping the signal. It's not even able to 'improve' the sound; all it can do is deviate from good to great measurements negatively and have people experience that as an improvement. It's comparable to brushing your teeth: You can do it with a super expensive brush or with a wooden one, but at the end of the day the ultimate performance would be to get rid of all the plaque. If the wooden one can do it as well as the super expensive one, they're both equal when it comes to the end result. Such is the case with amping as well, except that it just so happens to be that amping has been figured out and can be had for cheap. That is to say, the super expensive high tech brush can be bought for about a hundred bucks in the shape of a fiio e9k.

What remains are bad amps, exoticly designed amps and super expensive amps, that have you believe some magic is going inside that somehow manages to re-invent the wheel of amping. Newsflash: if there really was some kind of added functionality that improves sound quality that you can find in a kilobuck tube audio product, it would be the number one thing to sell the product with. Just the fact that that doesn't happen, should tell you plenty.

 

The belief is also that anything that's proven to measure well "only cares about measurements but not about sounding good" and "is analytical and cold sounding". Just in the last month I have seen amps/DACs such as the Benchmark and O2 been accused of such multiple times, ofcourse without so much as a word on double blind testing.

 

TLDR amping can be transparent because there are scientific goals set for it. When the amp achieves those goals - which is a very, very realistic possiblity - the amp can be considered transparent because it does nothing besides carrying out the scientific task of amplification, with errors only beyond human hearing (which is part of its technical purpose).


Edited by SunshineReggae - 3/23/13 at 7:39pm
post #1112 of 3453
Quote:
Originally Posted by SunshineReggae View Post

Quote:
Originally Posted by miceblue View Post

This has been kind of bugging me for a while (not just to pick on you, but in general):

 

How does one define what transparent "sounds like"? The O2 was designed to "sound transparent", so how can one justify something "sounds more transparent" and how can one actually actually confirm this? The designer of the O2 says it's transparent, but how does he know? I have heard multiple people say a Leckerton amp sounds more detailed than the O2; does this mean it's more coloured than the O2?

Warning: Good Explanation! (Click to show)

 

The last part means nothing, unless it can be demonstrated in double blind tests. Even then, it has yet to be ascertained whether it's actually an increase of detail you'd be talking about, or just more treble (or whatever).

 

The reason amps can be 'transparent' (which is not the same as 'transparent sounding', which is total nonsense because nobody knows what that even means) is because amping a signal is a science. If an amp measures well, it will perform accordingly. If it measures worse, it will sound different. The problem is that some people may feel that it sounds 'better' when it technically performs worse. At that point all bets are off and even the most badly designed amp can be conceivably sold. Another problem with audio is that impressions can hardly be verified, so even the most objective listener will be exposed to his own subjective preferences when evaluating gear.

 

All of that does not take anything away from the fact that amping is a science and that scientifically and technically, you can build an amp that objectively performs as well as possible when it comes to sound quality. Contrary to popular belief on headfi, an amp is not able to do anything magical that goes beyond measurements. It can not magically alter the amount of detail that is heard beyond what measurements account for. It can not be made to sound warmer or colder beyond making adjustments to frequency response (which is undesirable and I don't personally know any amps that shoot for strange deviations but I'm sure they're out there) or accounting for impedance mismatches. Likewise for soundstage, etc. The mistake that is often made is that people seem to think an amp is a way to beautify the sound, while in fact all it's supposed to do is to carry out the technical task of amping the signal. It's not even able to 'improve' the sound; all it can do is deviate from good to great measurements negatively and have people experience that as an improvement. It's comparable to brushing your teeth: You can do it with a super expensive brush or with a wooden one, but at the end of the day the ultimate performance would be to get rid of all the plaque. If the wooden one can do it as well as the super expensive one, they're both equal when it comes to the end result. Such is the case with amping as well, except that it just so happens to be that amping has been figured out and can be had for cheap. That is to say, the super expensive high tech brush can be bought for about a hundred bucks in the shape of a fiio e9k.

What remains are bad amps, exoticly designed amps and super expensive amps, that have you believe some magic is going inside that somehow manages to re-invent the wheel of amping. Newsflash: if there really was some kind of added functionality that improves sound quality that you can find in a kilobuck tube audio product, it would be the number one thing to sell the product with. Just the fact that that doesn't happen, should tell you plenty.

 

The belief is also that anything that's proven to measure well "only cares about measurements but not about sounding good" and "is analytical and cold sounding". Just in the last month I have seen amps/DACs such as the Benchmark and O2 been accused of such multiple times, ofcourse without so much as a word on double blind testing.

 

TLDR amping can be transparent because there are scientific goals set for it. When the amp achieves those goals - which is a very, very realistic possiblity - the amp can be considered transparent because it does nothing besides carrying out the scientific task of amplification, with errors only beyond human hearing (which is part of its technical purpose).

 

 

Hm thanks for the insight. That seems to make sense for the most part.

I asked because a lot of gear measures quite well (the newest iDevices for example), yet they all sound a little different.

 

The new JDS Labs C5 amp definitely has a smaller, more closed-in-sounding soundstage compared next to the O2 with some rough volume-matching, yet they both have the same THD+N measurements.

post #1113 of 3453

Headphone measurements are, as of today's methods and technology, a very inaccurate science due to the massive amount of variables that need to be taken into account including head size, headphone positioning, various volumes, integration of equal loudness contours, etc. etc. (but very precise as long as you stay within the boundaries of one site). Amp/DAC measurements, however, should theoretically be an exact science because all you need to do is measure the output with a wire and a dummy load on the component.

post #1114 of 3453
Quote:
Originally Posted by miceblue View Post

This has been kind of bugging me for a while (not just to pick on you, but in general):

 

How does one define what transparent "sounds like"? The O2 was designed to "sound transparent", so how can one justify something "sounds more transparent" and how can one actually actually confirm this? The designer of the O2 says it's transparent, but how does he know? I have heard multiple people say a Leckerton amp sounds more detailed than the O2; does this mean it's more coloured than the O2?

 

The reference for O2 supposedly was the headphone output of the Benchmark DAC1 and since many highly regarded audio newspapers and so on consider Benchmark DAC1 very transparent if you could not tell apart the O2 from the DAC1 in a blind test then you could say it is "as" transparent.

 

Imo I hear more differences from different DAC than differences from different amps. Ok, if something is badly designed so it has high distortion in an amp you should be able to hear that as some difference (warmer, less detail), but if something measures good then it's really hard to tell apart (maybe studio professionals can - you have to know what to look for and have a reference).

 

The term "detailed" is a little vague. I think most relate detail to treble, but I mean even bass can be detailed (but maybe it's a little harder to tell) - so for the Leckerton being more detailed I don't know. I have UHA-6S mkii and I like it very much. Yes it is detailed but more detailed than my O2, I don't know. To me they sound alike and both are very good.

 

Regarding amp coloration: I think it's there. I can hear that a Fiio E11 sounds a little warmer and is not as detailed in bass, treble and so on. Tube amps is a whole different story to me. I enjoy its sound a lot but it's a sound that is tampered with in different ways - like changing tubes sounds like changing different EQ's to me. Still it's fun to find a match that suits you, because everyone has a different taste in sound signature.

 

After awhile when I got the O2 I found that SS amps are the way to go for me. I like the whole picture better than the refined picture. Of course there are advantages and disadvantages depending mostly on what type of music you listen to. I find that SS amps suits me better as I like many different music genres.

 

I know people talk about dry sound, lush sound, liquid sound and so on. I'm having a little trouble to relate to these terms - I'm starting to know what it's about. I think it shows more in the higher price chain. I'm getting a Vioelectric HPA V100 in the near future so it will be interesting to hear what that has to offer in comparison.


Edited by Deni5 - 3/23/13 at 9:02pm
post #1115 of 3453

IMO I hear more differences from different DAC than differences from different amps.

 

There's a huge difference between a low-fi and mid-fi DAC, for sure; however, I remain unconvinced that there is very much, if any, difference between a mid-fi and a hi-fi DAC. I was unable to tell the difference between the PerfectWave DAC II ($4,000) and the ODAC ($150) under meet conditions with a switch time of half a second.

post #1116 of 3453
Quote:
Originally Posted by Tus-Chan View Post

IMO I hear more differences from different DAC than differences from different amps.

 

There's a huge difference between a low-fi and mid-fi DAC, for sure; however, I remain unconvinced that there is very much, if any, difference between a mid-fi and a hi-fi DAC. I was unable to tell the difference between the PerfectWave DAC II ($4,000) and the ODAC ($150) under meet conditions with a switch time of half a second.

I've tried the Asgard/Lyr combo at a meet and I actually thought it sounded worse than the O2/ODAC combo with my own audio CD. Instruments seemed a bit more blurry/less defined, bass seemed more present, details from the treble(?) weren't as apparent...

 

Yet that Schiit combo is quite popular here.

 

Clarification: I'm not to say the Schiit combo sound bad, I was just stating my own brief personal experiences with the K 701 at a local meet

post #1117 of 3453

With respect to amps, it's conceptually not that complicated.  There's an input signal and and output signal.  If there's no difference between the input and output (impossible, as there's always some noise, distortion, etc.), the amplifier hasn't changed anything—other than scaling everything up or down, which just changes the volume—and it's is delivering that exact input signal to the headphones.  Some people would call that transparent, whatever that means.

 

So nothing's perfect, but how about really close (defined and measured in what ways)?  After all, human aural acuity is not infinite.  If you get close enough, that might be called transparent too.  At a certain point, there might be nobody in the world that could reliably distinguish two things that are similar enough, be it sounds or images or whatever else.  Based on the reading of previous psychoacoustics research, the O2 designer came up with some measurable design parameters that an amp should exceed, in order to be close enough, that it should sound transparent, and then built something to meet those criteria.  That's the kind of process that many audio designers take, though not many others.  On the other hand, some people claim that there are issues with the psychoacoustics research and boundaries, or they claim that certain proper measurements were not taken or considered, or they argue that A and B and C and D are each insignificant on their own but potentially audible when combined, or they claim that amps have properties that can't be measured at all.

 

It depends on the headphones you're using, but there are plenty of ways that amplifiers might change the sound a little.  Quoted measurements can be very incomplete.  Just because THD+N is similar with 150 ohms at a certain output level doesn't mean it's similar driving 32 ohms, for example.  Or that the noise level is similar (it's not), as the HD part is dominating the N part of the measurement.  A slight difference in output impedance could make certain particular IEMs sound a bit different.  There might be a different amount of channel imbalance at different rotations of the volume pot.  And so on.

 

 

The big issue is that everybody's perception of sound is filtered by the brain.  What you perceive depends on a whole lot other than just the sound coming into your ear, such as the way you're listening, your mood, and preconceptions and expectations, etc.  It's unavoidable, no matter what the listener tries to do.  That's not to even mention any very slight differences between how headphones are positioned on the head between one listen and another, and other such environmental factors—which often seem to have a greater impact on frequency response and other measurables, than the differences between certain amps.

 

Some people perceive differences in the sound between different devices (of course, between listening to device X and device Y, as alluded to above, that is not the only variable that's changed), so that's they way they describe it.  But it's always possible that the differences are due to these other factors and not actually the sound produced, so other people claim it's not real, just in their heads.

post #1118 of 3453
Quote:
Originally Posted by mikeaj View Post

With respect to amps, it's conceptually not that complicated.  There's an input signal and and output signal.  If there's no difference between the input and output (impossible, as there's always some noise, distortion, etc.), the amplifier hasn't changed anything—other than scaling everything up or down, which just changes the volume—and it's is delivering that exact input signal to the headphones.  Some people would call that transparent, whatever that means.

 

So nothing's perfect, but how about really close (defined and measured in what ways)?  After all, human aural acuity is not infinite.  If you get close enough, that might be called transparent too.  At a certain point, there might be nobody in the world that could reliably distinguish two things that are similar enough, be it sounds or images or whatever else.  Based on the reading of previous psychoacoustics research, the O2 designer came up with some measurable design parameters that an amp should exceed, in order to be close enough, that it should sound transparent, and then built something to meet those criteria.  That's the kind of process that many audio designers take, though not many others.  On the other hand, some people claim that there are issues with the psychoacoustics research and boundaries, or they claim that certain proper measurements were not taken or considered, or they argue that A and B and C and D are each insignificant on their own but potentially audible when combined, or they claim that amps have properties that can't be measured at all.

 

It depends on the headphones you're using, but there are plenty of ways that amplifiers might change the sound a little.  Quoted measurements can be very incomplete.  Just because THD+N is similar with 150 ohms at a certain output level doesn't mean it's similar driving 32 ohms, for example.  Or that the noise level is similar (it's not), as the HD part is dominating the N part of the measurement.  A slight difference in output impedance could make certain particular IEMs sound a bit different.  There might be a different amount of channel imbalance at different rotations of the volume pot.  And so on.

 

 

The big issue is that everybody's perception of sound is filtered by the brain.  What you perceive depends on a whole lot other than just the sound coming into your ear, such as the way you're listening, your mood, and preconceptions and expectations, etc.  It's unavoidable, no matter what the listener tries to do.  That's not to even mention any very slight differences between how headphones are positioned on the head between one listen and another, and other such environmental factors—which often seem to have a greater impact on frequency response and other measurables, than the differences between certain amps.

 

Some people perceive differences in the sound between different devices (of course, between listening to device X and device Y, as alluded to above, that is not the only variable that's changed), so that's they way they describe it.  But it's always possible that the differences are due to these other factors and not actually the sound produced, so other people claim it's not real, just in their heads.

You bring up some very good points there; thank you for the explanation.

 

You mention measurements often being incomplete, I think the same can be said for the O2 and ODAC as well. The designer of the Objective gear only did so many tests too.

I brought up Leckerton in a previous post because I think it was Currawong(?) who said that the O2 may sound good, but it may have a non-linear response in certain cases....I can't completely remember what was said. I recently came upon this website with different measurements between a Leckerton amp and the O2 and from those specific measurements, the Leckerton performed better objectively than the O2. Would this non-linearity be a reason why some people say the Leckerton sounds "more detailed" than the O2?

post #1119 of 3453
Quote:
Originally Posted by Tus-Chan View Post

 

There's a huge difference between a low-fi and mid-fi DAC, for sure; however, I remain unconvinced that there is very much, if any, difference between a mid-fi and a hi-fi DAC. I was unable to tell the difference between the PerfectWave DAC II ($4,000) and the ODAC ($150) under meet conditions with a switch time of half a second.

 

I find it a little strange that people are changing amps more often than changing dac's (or so it can sometime seem when reading). Most of the times the dacs in computers and mobilephones aren't a optimal solution (to cut down total cost some parts have to be cheaper).

 

Anyway I find the ODAC really good. I find differences comparing to my Dacport LX and Meridian Explorer. But I would say not better differences.

post #1120 of 3453
Quote:
Originally Posted by Deni5 View Post

Quote:
Originally Posted by Tus-Chan View Post

 

There's a huge difference between a low-fi and mid-fi DAC, for sure; however, I remain unconvinced that there is very much, if any, difference between a mid-fi and a hi-fi DAC. I was unable to tell the difference between the PerfectWave DAC II ($4,000) and the ODAC ($150) under meet conditions with a switch time of half a second.

 

I find it a little strange that people are changing amps more often than changing dac's (or so it can sometime seem when reading). Most of the times the dacs in computers and mobilephones aren't a optimal solution (to cut down total cost some parts have to be cheaper).

 

Anyway I find the ODAC really good. I find differences comparing to my Dacport LX and Meridian Explorer. But I would say not better differences.

I read Tyll's article on Innerfidelity about the Meridian Explorer. Do you have the first version, with the high output impedance?

post #1121 of 3453
Quote:
Originally Posted by miceblue View Post

I read Tyll's article on Innerfidelity about the Meridian Explorer. Do you have the first version, with the high output impedance?

 

Yes, I do. But I'm not using the headphone out at all. I use the line out to an external amp (O2 or UHA-6S mkii) so no issues at all in that configuration.


Edited by Deni5 - 3/23/13 at 9:38pm
post #1122 of 3453

There is one thing about amp/DAC comparisons that annoys me whenever it is mentioned: soundstage. An amplifier or a DAC should not change soundstage because soundstage, as far as I know, is defined by two things:
 

  1. size/distance/direction of drivers
  2. stereo mixing channel imbalance (cymbal is 75% louder in right than in left ear = soundstaged towards right)

 

If you're driving your headphones correctly and you've got the volume matched, there shouldn't be any difference.

post #1123 of 3453
Quote:
Originally Posted by Tus-Chan View Post

There is one thing about amp/DAC comparisons that annoys me whenever it is mentioned: soundstage. An amplifier or a DAC should not change soundstage because soundstage, as far as I know, is defined by two things:
 

  1. size/distance/direction of drivers
  2. stereo mixing channel imbalance (cymbal is 75% louder in right than in left ear = soundstaged towards right)

 

If you're driving your headphones correctly and you've got the volume matched, there shouldn't be any difference.

It's possible. Perhaps our definition of soundstage is different?

From Stereophile:

Quote:
soundstaging, soundstage presentation The accuracy with which a reproducing system conveys audible information about the size, shape, and acoustical characteristics of the original recording space and the placement of the performers within it.

Of course accuracy is pretty irrelevant, at least from my understanding, unless you know exactly how the recording was put together or the way the instruments were arranged.

 

I've tried using a 1 kHz file produced from Audacity to volume match 2 amps by-ear (I know it's not the most accurate way to do it, but it's the best I have access to at home)

I've played the same loop of music through my setups: MacBook Pro -> Audirvana Plus -> ODAC -> amp -> headphone

I've used the same interconnect cable to switch from amp to amp

I've used the same headphone in the same position on my head from amp to amp

Switching times were less than a second

 

From my testings, I could hear a pretty evident difference in the way the instruments are spread-out in my head between the JDS Labs C5 and the O2. The two points you mention are irrelevant with the setup. I could try a more scientific method of volume matching with a pretty beefy multimeter at school, but from the many tests I've done, I think my observations would remain the same.

 

Apart from my own personal testing, wouldn't different amounts of distortion, or measurement differences in general, affect how the output sounds anyway?

And I bring this up again, what measurement accounts for the soundstage? I find the O2 to have a pretty wide soundstage compared to other amps I've tried in my rather limited list.

post #1124 of 3453

Describe the differences you heard.

post #1125 of 3453
Quote:
Originally Posted by miceblue View Post

You bring up some very good points there; thank you for the explanation.

 

You mention measurements often being incomplete, I think the same can be said for the O2 and ODAC as well. The designer of the Objective gear only did so many tests too.

I brought up Leckerton in a previous post because I think it was Currawong(?) who said that the O2 may sound good, but it may have a non-linear response in certain cases....I can't completely remember what was said. I recently came upon this website with different measurements between a Leckerton amp and the O2 and from those specific measurements, the Leckerton performed better objectively than the O2. Would this non-linearity be a reason why some people say the Leckerton sounds "more detailed" than the O2?

 

For a perfectly ideal linear system (and time invariant) one perfect measurement is sufficient.  For everything in the real world, you need more if you want a better characterization.  So yeah, we've seen a lot on the O2 from the designer and others but not everything (can't get everything), and we've seen just some on the ODAC.  However, the more well-behaved something is and closer to ideal, the closer the output would be to a completely known and predictable response, so I wouldn't expect huge surprises lurking if you were to somehow test some different signal or some other reasonable audio input and setup.

 

An unevenness in frequency response is not a nonlinearity, by the technical meaning of the word, by the way, but I see what you mean.

 

Note that the difference in frequency response as measured for that test is pretty much entirely a direct consequence of the slightly higher output impedance.  With pretty much anything other than a certain IEM with a really wild impedance curve, it would be much much flatter (and even considering extreme cases like these, do fraction of a dB differences really have much impact on the sound?  Discernible and shouldn't be trivialized, but put it in perspective.).  Many or most people talking about the different amps probably aren't using those exact IEMs; you'd see something else with some other IEMs or headphones.

 

Even if you were to assume that everybody comparing were using an IEM like that, an FR difference like that is unlikely to make people think one device is more detailed than another.

 

 

 

As I mentioned before, you can find differences with some bench measurements, but do they really correspond to what people say they hear?


Edited by mikeaj - 3/23/13 at 10:51pm
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