O2 Build Complete: Let the objective, subjective listening tests commence!
Dec 23, 2011 at 1:49 AM Post #691 of 721

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please forgive my extreme lack of technical knowlege when asking a quesiton like this:
 
ok, so i have my O2 ordered, and it clearly measures excellent, but what happens when say for example i play it next to my soon coming stacker II and the stacker maybe has a much "larger" sound - as in feels like it expands off of my head more, or if the stacker seems to seperate instruments more, or other attributes that i cant think of at this point that arent frequency or distortion related.  my question is what in the stacker would be causing these "improvements"
 
i'm just using the stacker as an example, but my real question is - some amps may sound better than the O2.. now i have heard that some people prefer tube amps and what it comes down to is that the tubes ad distortion or some other kinds of "less than optimal" measurement factors or tube factors that color the sound or frequency response, and that some people actually prefer that, but the aspects im asking about are specifically not frequency response or distortion realated.
 
i hope this question makes sense.  I'm just trying to learn something here.
 
i guess another hypothetical way to ask this is - lets say you took the O2, and another amp that measured equally well, but sounded a lot better for whatever reason you want to imagine, what would be the differences? I sort of understand that better is not always actually better in some cases, but hopefully you get my drift.
 
thanks


if you want to get serious, you need to level match the amplifiers.  you need a DVM, unterminated TRS plug or detachable HP cable, and a test tone.  go down to your local hardware store and Radio Shack and pick up a DVM ($10-20) and TRS plug ($4).  i can run you through the process via PM if interested. 
 
 
Dec 23, 2011 at 2:02 AM Post #692 of 721


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This right here screams some sort of coloration on that particular B22's part. Whenever someone calls an amp "digital" or implies such, they're usually looking for coloration and not getting it.


this screams "i've never heard a B22".
 
Dec 23, 2011 at 2:18 AM Post #693 of 721


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all this talk kinds makes a brother want to buy a dac-1 pre sell all my other gear and call it a day.  of course until the ODA comes out.
 
 



Nothing drastic like that.  Take a listen to the gear you have incoming, and if you like it enjoy.  Whether an amp colors the music(in a good way) or not is only relevant if you insist it doesn't.  My choice is an amp that doesn't add anything but sufficient volume/gain.  I like to compare headphones on their own sound signature and not "synergy".
 
Dec 23, 2011 at 5:01 AM Post #694 of 721


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 ...lets say you took the O2, and another amp that measured equally well, but sounded a lot better for whatever reason you want to imagine...

 
I would maintain such a situation would not/could not exist if the measurements were done properly, and the comparisons between them were volume matched and blind.
Additionally, you would be amazed how your brain interprets differences in volume and other perfectly measurable things: an increase in instrument separation could easily subjectively result from slightly higher volume.
 
 
Dec 23, 2011 at 5:51 AM Post #695 of 721


Quote:
 
I would maintain such a situation would not/could not exist if the measurements were done properly, and the comparisons between them were volume matched and blind.
Additionally, you would be amazed how your brain interprets differences in volume and other perfectly measurable things: an increase in instrument separation could easily subjectively result from slightly higher volume.


Or if that does happen, we would need to revise how objective values apply to subjective enjoyment. However, and I'm just as lost as Br777 here, I thought the Beta22 was supposed to be a well-measuring amp as well, like a big O2. So if they both measure very well, yet someone finds very audible differences between the two, shouldn't we try to understand why besides just dismissing as bias? He posted this which intrigued me, since I expected sonic differences to be minimal.
 
 
That post kind of scratches on my issues with the O2 when compared to the Beta22 (3 channel version).
 
-Instrument separation is very lacking.
-Faster music gets jumbled
-Snare drums sound life like on a beta22, yet sound like a recorded snare drum with the O2
 
Or is the Beta22 colored?
 
Dec 23, 2011 at 6:40 AM Post #696 of 721


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I don't really hear differences like that between my Crack and O2.  Just a little tubey warmth.  I don't have the speedball upgrade for mine though.
 
You ordered an O2 right?  Did it come in yet?


Not yet, it's coming.  The particular tube matters, I've got about 30+ 6SN7s laying about here.  The whole tube warmth thing is just the tip of the iceberg.  Unless you prefer cold analytic tubes.  
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Dec 23, 2011 at 6:43 AM Post #697 of 721


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@Anaxilius
That wouldn't be much fun: NwAvGuy maintains that they (the Benchmark and the O2) are indistinguishable under blind conditions (based on his own ABX testing with a few other unknown people involved) and the O2 measures a fair bit better in most areas anyway (although certainly not audibly better!)*
I'm also a little skeptical about the existence of tube sound as a sound signature which is vastly different from solid state. Even with their higher distortion and wonky FR, I would wager they sound pretty similar to their SS brethren more often than not, especially the more expensive models (which ironically seem to be trying to remove the reason for buying a tube amp in the first place...IDK, never "got" the idea of amps with built-in colouration. We have DSPing for that)
 
 
*Just talking about headamp performance here; the Benchmark's performance as a DAC is beyond reproach IMHO.
 


We'll see, my HD800 should do better to flesh out differences than the HD650.  The Benchmark is pretty good, not the best amp section out there but if the O2 can emulate it's HPO for that much less who can argue about that.
 
 
 
 
Dec 23, 2011 at 7:19 AM Post #698 of 721


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Or if that does happen, we would need to revise how objective values apply to subjective enjoyment. However, and I'm just as lost as Br777 here, I thought the Beta22 was supposed to be a well-measuring amp as well, like a big O2. So if they both measure very well, yet someone finds very audible differences between the two, shouldn't we try to understand why besides just dismissing as bias? He posted this which intrigued me, since I expected sonic differences to be minimal.
 
 
That post kind of scratches on my issues with the O2 when compared to the Beta22 (3 channel version).
 
-Instrument separation is very lacking.
-Faster music gets jumbled
-Snare drums sound life like on a beta22, yet sound like a recorded snare drum with the O2
 
Or is the Beta22 colored?



The Beta22, like most DIY designs, has never been comprehensively measured, so it performing objectively excellently is not necessarily a foregone conclusion.
 
Dec 23, 2011 at 9:11 AM Post #699 of 721
The beta22 has never been measured on something like dscope as far as I know. However, knowing the amount of simulation testing that was done on it, the RMAA results, and the design topology makes me pretty confident that it would measure well, though RMAA results seem optimistic in some areas, particularly crosstalk. I think it is more likely that the above comments were not made 'blindly' and bias is influencing the opinion.
 
Dec 23, 2011 at 1:58 PM Post #700 of 721
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Not yet, it's coming.  The particular tube matters, I've got about 30+ 6SN7s laying about here.  The whole tube warmth thing is just the tip of the iceberg.  Unless you prefer cold analytic tubes.  
wink.gif


I'd be interested in what you think about the O2 with the HD800s.
 
Quote:
We'll see, my HD800 should do better to flesh out differences than the HD650.  The Benchmark is pretty good, not the best amp section out there but if the O2 can emulate it's HPO for that much less who can argue about that.


What don't you like about the DAC1's HPO?  Are you looking for something "beyond" measurements or just a specific coloration?
 
 
Dec 23, 2011 at 4:52 PM Post #701 of 721
 


...if they both measure very well, yet someone finds very audible differences between the two, shouldn't we try to understand why besides just dismissing as bias?

 
The fact is that claims of audible differences are easy to make, but substantiated audible differences are thin on the ground.
 
When I say substantiated, I mean differences that are repeatably detected in controlled blind testing.
 
This particular type of argument has rattled on for years (2 or 3 decades, maybe 4). Many people don't understand that it's not enough to think you hear a difference, you have to be able to demonstrate that you can hear a difference.
 
When somebody comes along with a new claim, and it's obvious that they don't have any substantiating evidence, then those of us who have been fending off such unsubstantiated claims for years get a bit impatient. It's not that we're not interested to hear if somebody can prove that they can hear a difference, but we no longer have time for anybody who doesn't realize that that is what is required, especially since the sheer volume of unsubstantiated claims muddies the water and gives rise to a shower of naiive questions such as yours. Please understand that I don't mean to be derogatory when I say this, I understand that you are trying to give a fair hearing to an expressed point of view, but experience has shown that not all participants in the argument are acting fairly, because...
 
...this is not the end of the argument.
 
Some (many) people have tried to substantiate their claims and failed. An obvious and recent case is the claimed superiority of greater bit depths and higher sample rates over the 16/44k1 of standard CDs. Blind testing, however, in which these supposedly superior formats were squeezed down to 16/44k1 have shown that nobody can tell the difference between the squeezed and unsqueezed versions.
 
This leads to suggestions that blind testing itself is flawed, or that the circumstances of the test blunt the perceptions of the individual or individuals participating in the testing, resulting in inaccurate results.
 
Blind testing is the last resort when attempting to ascertain the truth of any result in which human perceptions or reactions are involved. It is how we discriminate between effective drugs and placebos. In my opinion it is at least to fly in the face of reason to dispute its efficacy, and ultimately pointless, because there is nothing to replace it and no alternative other than endless dispute. At worst it is immoral, because it's a position taken by many in order to continue to profit, either from sales or in the publishing business.
 
w
 
Dec 23, 2011 at 5:42 PM Post #702 of 721
I understand that blind testing and measurements are essentially much more important than sighted opinions, and in fact measurements are more objective and reliable than sighted (since a measurement is a number, and sighted listening is still purely subjective). I'm not even putting that into question. I am, or study to one day be, a scientist, I know that to design a drug you need to study the enzymes it will affect, calculate how it will respond with the normal metabolism, all that. But you never not ask a human test population what they thought do you?
 
My point is, I'm not saying that one guy's opinion deserves to be taken as seriously as a measurement, or even as if it was a blind opinion. However, a subjective opinion, or as many as you can get, are still crucial. I always read the graphs of a pair of cans I'm buying, but I also read every review I can find, because - and I admit this can just be my ignorance - I know that objective facts do not have a direct relation to our enjoyment, something neutral might sound "boring". Luckily for me, objective measurements usually correlate with subjective listening, i.e. something that measures well usually sound good unless you like coloration. So when a guy comes along saying "this amp sounded better in these aspects that that other one", although I won't give it as much importance as Voldemort's measurements, I don't immediately dismiss it either.
 
tl;dr: I never said to be either an objectivist or a subjectivist, but a believer of the correlation of both. Each has their respective value to me, and they usually go along with each other.
 
Dec 23, 2011 at 6:13 PM Post #703 of 721
Quote:
I understand that blind testing and measurements are essentially much more important than sighted opinions, and in fact measurements are more objective and reliable than sighted (since a measurement is a number, and sighted listening is still purely subjective). I'm not even putting that into question. I am, or study to one day be, a scientist, I know that to design a drug you need to study the enzymes it will affect, calculate how it will respond with the normal metabolism, all that. But you never not ask a human test population what they thought do you?


You do, but you do it in a controlled environment and with a control group. Hence why I said if you hear a difference, set up a blind test with Voldemort. Maybe earn yourself some money, and make your impressions meaningful.
 
Your analogy isn't perfect, either. The human body is a lot more complicated than an amp. There can be unseen consequences to medicines, and those consequences can result in lawsuits. So testing is absolutely vital, both financially and scientifically. With audio, electricity is predictable and well understood, and no one's going to sue you if they can hear distortion at a frequency you never measured. Heck, they might even like it.
 
You find differences that shouldn't be there, by all means test and research. But you have to eliminate the human bias first, because it's far more significant than any difference in THD.
 
Dec 23, 2011 at 7:31 PM Post #704 of 721


Quote:
 
... the sheer volume of unsubstantiated claims muddies the water and gives rise to a shower of naiive questions such as yours. Please understand that I don't mean to be derogatory when I say this, I understand that you are trying to give a fair hearing to an expressed point of view, but experience has shown that not all participants in the argument are acting fairly, because...  
...this is not the end of the argument.....
w



 
this issue is that most of us, myself included simply are not aware of the facts or their existance.  I mean look at this forum, look at its size, look at the innumerable number of amps, dacs, cables, etc being discussed, with great passion, and look how much of it is essentially just b.s. depending on what angle you are coming from.
 
Honestly when a thread like this, or a blog like nwavguy's comes along, even though it absolutely makes sense, and is at least from my uneducated perspective nearly impossible to argue with, our minds simply cant just let all that other conditioning go.  We doubt, we second guess, we simply cant compute that a $140 DIY amp could be the end all be all even if its proven up oneside and down the other.
 
this is why we ask questions like that one earlier - ...if they both measure very well, yet someone finds very audible differences between the two, shouldn't we try to understand why besides just dismissing as bias?
because almost no one in the world of audio understands or admits to the fact that situations like this are not possible.
we dont even know to question claims that say they are possible.
 
this is a great thread! :wink:
 
 
Dec 23, 2011 at 8:22 PM Post #705 of 721
This will get attacked, no doubt.  However, keep in mind that this thread is based on an amp design that was not based on Head-Fi, was designed by a user that was banned from Head-Fi, and it has no native support on this forum whatsoever.  Add to that many of the posts in this thread and the one before it (locked and removed) contain some of the most contradictory opinions about what makes a good amp that you'll find anywhere.
 
I'm sorry.  I fight to keep from posting in this thread every day.  Yet, when I find some earnest new enthusiasts to the hobby that are quite simply - being led astray - I lose that battle to keep from posting.  There is such a vast ... vast ... array of experiences and designs that you have yet to enjoy, it's almost criminal to focus on the narrow worship of the opinions parroted from he-who-shall-not-be-named.
Maybe we need a Harry Potter/Hogwart's School of DIY-amps to show people what's available outside of the Dark Arts.
popcorn.gif
  Sorry - I'll go back to my Defense of the Dark Arts amplifier class and leave you all alone for awhile.
 
 
 
P.S. Head-Fi is the Gryffindor of the headphone community.  Use its resources.  Go and seek advice at other places on Head-Fi besides this Slytherin thread.
wink.gif

 

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