O2 Build Complete: Let the objective, subjective listening tests commence!

[Br777]

For those of you who have read about the ODA (desktop version of O2)
are there any indications that is is designed to sound better, or is it simply more desktop optimized?
 
 

 

[maverickronin]

I can't link it, but you can read the preview article on his site if your interested.
 
Mostly its about having room for 1/4" headphone and RCA jacks and not having everything squished together on one side.  The power supply will be a little nicer too.  He said that it may make it measure a little cleaner but that the difference shouldn't be audible since the people he's tested already can't tell it apart from his DAC1's amp.

 

[mikeaj]

If I am reading between the lines correctly, I think it's supposed to have the same structure for the actual amp part, with the NJM4556 outputs and so on.  I don't think the supply voltages will be increased, so no more output voltage swing to play those vintage K240 models a little louder.
 
I guess you could say it should sound better on power on and off, since there's supposed to be a relay to prevent the click and poof.  O2 power on/off transients are not that loud though.
 
I think he's hoping for slightly better performance given the power supply improvement (though that should have marginal impact for this design), maybe less crowded and better PCB layout, and use of 6.35mm jacks which have lower crosstalk than 3.5mm jacks.  That's more of an academic exercise though.

 

[francisdemarte]

Br777:
 
I'll trade you my O2 for your Stacker 2 

 

[Shike]

Quote:

Not at all.  Most of his description fits to a T a typical Chrome Top 6SN7 sound.  You can try to attribute the richer, fuller bass to a shift in the FR due to output Z, which is likely correct, but not the staging, details, imaging, treble presentation, etc.  No way the O2 will compete with that as I've yet to hear any SS amp do that.  Not really a fair comparison between the two tbh.  The Benchmark HPO is more appropriate.

When you modify gains in bass, you also modify the level of distortion.  We could also question phase and a few other things.  There's going to be some definite measurable difference that's easy to point at that explains the difference.  Heck, I'm pretty sure it wasn't even level matched.  Until we have the same impedance, phase, and level matching then it's pretty much hard to prove the "golden tube sound" - especially in this case.
 
@Willakan
 
Most higher priced tube amps I've seen use proper output transformers which produce more linear response and lower output impedance.  So yes, they definitely reduce the difference between the two.
 
EDIT:
 
fixed typo for clarity

 

[Br777]

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

 

[Head Injury]

Quote:

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

"Large" sound can very much be affected by frequency response. I EQed my LCD-2's lower mid-range down slightly yesterday (only about 1 dB) and it gives the illusion of a larger sound stage because male voices, bass guitar, and harmonics sound a little further away.
 
It's also very much affected by volume. Everything is. If you make sure the amps are volume matched, that "large" sound might disappear.
 
Distortion might give the illusion of differences in size and space, but they'd have to be excessive.
 
I believe differences in phase are often attributed to differences in sound stage.
 
There's always expectation bias and placebo too, of course.
 
If you find an amp that measures equally well but sounds better, set up a blind test with Voldemort and earn yourself $500 

 

[wakibaki]

Quote:

...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...

 
er, it won't.
 
There is a limit to how 'good' an amp can be. Once you reach that limit it sounds exactly the same as any other amp which has reached that limit.
 
You understand what I'm saying? An amp can be improved to the point where all its flaws are inaudible, after that there is no where to go. It's essentially reproducing the sound from the source perfectly, as far as human hearing is concerned.
 
Some people think that ears will always be better than electronics, but this has never been shown to be true in any scientific sense, so it's kind of like saying 'I can see further than the Hubble telescope, and even if you made it better, I would still be able to see further, no matter how much better you made it and the only reason I can't prove it is because I don't perform well in test situations.'
 
Which I can by the way. I can see beyond the edge of the universe, but I can't tell you about it because you'd find it upsetting.
 
Amplifiers are probably the most perfectible element in a reproduction system other than the storage medium. You can probably get a better recording microphone, recording mixer (maybe, it's not much more than a bunch of amplifiers), recording A/D (maybe) and clock, playback DAC and clock (maybe), headphones (maybe, there's some variation in fit). As regards storage medium, CDs might leave something to be desired, solid state memory is pretty much perfect. We know this because if we find the information on our computers changes, then they stop working and we call this condition broken.
 
The big problem is that many people think that that you can always get a better amplifier, and you can in terms of measured performance, but it is also not true, not in terms of human perception, anyway.
 
w

 

[mikeaj]

Anyway, the point is that if you're hearing differences between devices that are so good as to be indistinguishably good...then you're imagining those differences, or you're comparing them at different volumes or listening conditions or something like that.  Maybe this sounds overly dismissive, and a lot of people don't like to be told that, but that's how it is.
 
It's very easy to imagine differences when none exist, by the way, so it's not like I'm accusing anybody of being anything more or less than human.  Isn't there some study where people were told to listen to sample A and sample B (which were actually the exact same, but they didn't know this) and choose if they preferred A / B / no preference, and 75% of people chose A or B?

 

[Br777]

well, assuming all this is true, this is truly news to me.   I always thought that some amps were simply designed in a superior way as to give a bigger soundstange, or headstage, or whatever the proper term is for larger field of sound.  Same with instrument seperation, or detail retrieval and so on. 
 
I guess it really just goes to show you how very gimiky the audio world is, though there is something to be said for people prefering a "colored" sound.  or prefering for example tube amps for all the various sound or  non-sound related reasons.
 
 

 

[Br777]

see, but then someone says something like this
 
snipped from another thread -
 
 
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
 
 
so, when someone says that, can their findings be proven, or disproven via measurements? or is this something that you'd have to rely on blind testing to prove or disprove?  or is this just dismissed as a case of sorry dude but you've succumed to subjective bias?
 
I'm genuinely intrigued by this.
thanks

 

[shadow419]

Quote:

see, but then someone says something like this
 
snipped from another thread -
 
 
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
 
 
so, when someone says that, can their findings be proven, or disproven via measurements? or is this something that you'd have to rely on blind testing to prove or disprove?  or is this just dismissed as a case of sorry dude but you've succumed to subjective bias?
 
I'm genuinely intrigued by this.
thanks

Subjective impressions like those are nearly impossible to prove/disprove through measurements imo.  I'd never dismiss someone's impressions outright unless I'm running the same gear, but the Pepsi challenge gauntlet still hasn't been picked up.  Take that how you like. 

 

[fubar3]

Quote:

It's very easy to imagine differences when none exist, by the way, so it's not like I'm accusing anybody of being anything more or less than human.  Isn't there some study where people were told to listen to sample A and sample B (which were actually the exact same, but they didn't know this) and choose if they preferred A / B / no preference, and 75% of people chose A or B?

And the human brain does not have 100% fidelity. There are real-time filters and lossy algorithms so that those 100 billion neurons don't get saturated. Neurons eventually die and must get replaced. This occurs during dreams which as anyone knows is a far cry from high-fidelity reproduction.
 
The point of all this blather is we don't fully experience the real world, we build an abstract, simplified model of the world veiled by sense perception and wishful thinking.
 
 

 

[Head Injury]

Quote:

-Snare drums sound life like on a beta22, yet sound like a recorded snare drum with the O2

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.

 

[Br777]

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.