[ishmael]

Quote:

It doesn't. 

  It's like trying to judge the taste of an orange with a mouth full of toothpaste. 

 
 
What do you mean, that sounds like it would be delicious. 

 

[Radio_head]

Quote:

Its too bad this thread has degenerated away from the O2 amp and ODAC.....
 
I am out of here....
 
Alex

 

[lorriman]

Most people agree the Odac is good for the price. 

This is cunning negative spin. The whole point is that it has been independently verified to be true hifi, reproducing the music exactly as produced and at high power. That's really not "good for the price".

And 'Most' people? Who are these people? Where are the concrete numbers? At least do a poll.

The arguments all start with the wild, inexperienced, often quite ignorant claims his minions make, which are fueled by V's motives and methods.  So clearly we start talking about that.  If his minions would stick to topics both subjective experience and objective knowledge they really had experience with and understood, these threads would stay much more rational and honestly quite positive, because everyone I know with good ears, experience with a lot of gear, and great understanding of measurements etc, think the Odac is good for the price. 

The statements you have made there are moving targets. How do you know they have good ears? And what do you mean by "great understanding of measurements"? Where are the measurements/stats, blind-testing that proves these statements? What blind tests exist show that ears cannot be relied upon. So called 'Golden ears' reliably fail double-blind testing.

In the meantime, instead of offering unverified and moving target statements and anecdotes, the designer has fully documented his approach and never had an argument on any of the forums in which he has been caught out. And let's not forget that independent verification.

 

[lorriman]

Well the amp is not nearly as transparent as the ODAC which is why I'm not as big a fan of it yet it's exhaulted as sonic perfection simply out of lack of a better reference by most.

'Not nearly'? Where does that come from? The measurements have the ODAC as better, yes, but the O2's issues are inaudible. They are both, with a human listener, transparent fro practical use.

 

[purrin]

Actually, I'm more impressed by the O2 than the ODAC. The ODAC sounds different depending upon what it's plugged into. The O2s main issues with me are treble stridency and some weakness in the bass. Both can be remedied with an op-amp swap to the LM4592 which I have done myself. The O2 excels is how clean and controlled it sounds. However, the O2 does sound flat in terms of both micro and macro dynamics, and does not extract detail anywhere as well as better amps, e.g UHA-6S, Schiit Mjolnir, etc. Heck, even a slightly colored tube hybrid amp such as the Melos SHA-1 is does dynamics and resolution better. This is of course dependent upon source and transducer quality: DAC, recording, and headphones.
 
Of course YMMV. The fact that I would be hard pressed to find anything better for less than ~$279 speaks volumes about the O2.

 

[rhythmdevils]

Quote:

This is cunning negative spin. The whole point is that it has been independently verified to be true hifi, reproducing the music exactly as produced and at high power. That's really not "good for the price".
And 'Most' people? Who are these people? Where are the concrete numbers? At least do a poll.
The statements you have made there are moving targets. How do you know they have good ears? And what do you mean by "great understanding of measurements"? Where are the measurements/stats, blind-testing that proves these statements? What blind tests exist show that ears cannot be relied upon. So called 'Golden ears' reliably fail double-blind testing.
In the meantime, instead of offering unverified and moving target statements and anecdotes, the designer has fully documented his approach and never had an argument on any of the forums in which he has been caught out. And let's not forget that independent verification.

 
How many amps and dacs have you heard?  

 

[Jimmy24]

I'm using an O2 with HD 650s. How much gain are you guys using for normal listening? I usually have mine about 2 bars. If I want to really hear everything in the mix I set it up to a little less than half way. 

 

[juantendo8]

Quote:

I'm using an O2 with HD 650s. How much gain are you guys using for normal listening? I usually have mine about 2 bars. If I want to really hear everything in the mix I set it up to a little less than half way. 

 
I think that low gain (2.5X) should be just fine for the 650s. They're really not that hard to drive.

 

[mikeaj]

Quote:

I'm using an O2 with HD 650s. How much gain are you guys using for normal listening? I usually have mine about 2 bars. If I want to really hear everything in the mix I set it up to a little less than half way. 

 
Hm, how much gain?  Clearly that depends on the output level of the source you're amplifying, the headphones too.
 
None of my headphones need incredible amounts of voltage, so with a 1V rms source I just have 1x and 3.1x gains.  It's on 1x except for some classical music recordings with the relatively insensitive headphones.  With HD 650s I'd be using 1x for myself, most of the time.

 

[gnarlsagan]

Actually, I'm more impressed by the O2 than the ODAC. The ODAC sounds different depending upon what it's plugged into. The O2s main issues with me are treble stridency and some weakness in the bass. Both can be remedied with an op-amp swap to the LM4592 which I have done myself. The O2 excels is how clean and controlled it sounds. However, the O2 does sound flat in terms of both micro and macro dynamics, and does not extract detail anywhere as well as better amps, e.g UHA-6S, Schiit Mjolnir, etc. Heck, even a slightly colored tube hybrid amp such as the Melos SHA-1 is does dynamics and resolution better. This is of course dependent upon source and transducer quality: DAC, recording, and headphones.

Of course YMMV. The fact that I would be hard pressed to find anything better for less than ~$279 speaks volumes about the O2.

That's interesting! I might try that swap at some point. I'm not questioning your findings but I'm hoping you could be more specific about detail extraction differences between the O2 and the other amps you mentioned. Maybe a specific sound or section in a specific track? I just never know what to look for when people mention these kinds of things.

 

[mikeaj]

Quote:

That's interesting! I might try that swap at some point. I'm not questioning your findings but I'm hoping you could be more specific about detail extraction differences between the O2 and the other amps you mentioned. Maybe a specific sound or section in a specific track? I just never know what to look for when people mention these kinds of things.

 
Just a couple heads-up:
 
I think purrin's got a typo there.  You probably want an LM4562 (not LM4592, which doesn't exist?  or at least isn't common).  Hopefully this saves somebody some grief in looking up the part number.  

 
Secondly, there are some uncharacteristically brief THD and noise measurements of LM4562 in O2 circuit at that place (August), just for reference, to compare to whatever you hear.

 

[cyberalpha11]

Will O2 improve the bass in AKG K550 by making sound much heavier, tighter, deeper and punchier bass?

 

[mikeaj]

Quote:

Will O2 improve the bass in AKG K550 by making sound much heavier, tighter, deeper and punchier bass?

 
Compared to... what?

 

[NimbleTurtle]

Quote:

Will O2 improve the bass in AKG K550 by making sound much heavier, tighter, deeper and punchier bass?

From my limited knowledge of amps, it will have tighter bass that extends better but it won't get heavier unless you EQ it. 

 

[cyberalpha11]

Compared to... what?

Comparison "with" and "without"O2 when listening to K550.