Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › O2 AMP + ODAC
New Posts  All Forums:Forum Nav:

O2 AMP + ODAC - Page 172

post #2566 of 3374
Quote:
Originally Posted by Zorrofox View Post

So in that case all DAC's will sound the same?
Yes all dacs that meet the transparency criteria Will sound the same. Basically most modern dacs sound the same to human ears.
post #2567 of 3374
Quote:
Originally Posted by Zorrofox View Post

So in that case all DAC's will sound the same?

According to pure objectivsts, and those who worship NwAvGuy as a God, yes. According to people who embrace both objective measurements and subjective listening, such as myself, no. I don't think we can measure everything we listen. Just like many biological processes, we can only model and hence measure a small part of what goes on in the human body.

Purrin is a highly respected member and he has his own measurement rigs:
http://www.head-fi.org/t/693798/ranking-of-21-dacs-and-dac-configurations-and-why-chocolate-ice-cream-must-die
post #2568 of 3374
The odac is way past the point of transparency. You can either dwell on myths and bull**t or enjoy the music. I know which I am doing!
post #2569 of 3374
Quote:
Originally Posted by miceblue View Post

According to pure objectivsts, and those who worship NwAvGuy as a God, yes. According to people who embrace both objective measurements and subjective listening, such as myself, no. I don't think we can measure everything we listen. Just like many biological processes, we can only model and hence measure a small part of what goes on in the human body.

Purrin is a highly respected member and he has his own measurement rigs:
http://www.head-fi.org/t/693798/ranking-of-21-dacs-and-dac-configurations-and-why-chocolate-ice-cream-must-die
I read the first paragraph. It's so bias its untrue.
post #2570 of 3374

Thanks to some very gracious trouble shooting help from agdr (hint: having a diode in the wrong orientation is a bad plan), I'm pleased to report that I got my O2 booster board (v.3.0) [see http://www.diyaudio.com/forums/headphone-systems/244473-o2-headamp-output-booster-pcb.html ] up and running today and also swapped in the optional dual LME49990 adaptor for the stock gain chip (bringing the amp's slew rate up to a respectable 20V/us).

 

I'm very happy with the results!  DC offset is now essentially nonexistent per my cheap meter, turn on/off thump is eliminated, and the overall sound does seem to have improved in a couple of respects to my ears.  While acknowledging that this all may be attributable to the delusions of my heat oppressed brain (thanks Shakespeare and Hume!), I could swear that the minor treble glare I occasionally perceived in the O2 has vanished and the deep bass seems just a little bit more present.  For example, I have a great recording of traditional Anglican choral and pipe organ music that was made a few years back in the renowned St. Martin-in-the-Fields Cathedral (on Trafalgar Square) - http://www.amazon.com/Chorales-Preludes-David-W-Bowerman/dp/B008P76WZM/ref=sr_1_1?ie=UTF8&qid=1397345635&sr=8-1&keywords=choral+scholars+of+st+martin .  The organ, in particular, always sounded just the tiniest bit thin on my stock self-built O2 (relative to my mainline and also the live evensong services I made a point of attending at that Cathedral while traveling - the acoustics in which are arguably the best in the world for choral music).  With agdr's booster and the LME49990 adaptor in place, my AD's seem to be singing this music back just a bit closer to the sound of live.  

 

I think I'm going to have to build up my spare O2 board and related components so I can actually A/B rapidly between the stock and modified amps, but as noted by one or two others in the thread, agdr's board truly does seem to result in subjective as well as objective improvements!


Edited by skeptic - 4/12/14 at 5:24pm
post #2571 of 3374
At its best, the ODAC sound expansive, detailed, and precise in imaging. At its worst, the ODAC sounds closed-in, flat, dull, uninteresting, and with wooly bass (Class S). It depends upon the USB connection. Overall the ODAC is not as precise in rendering of sounds. This is where the comparable Modi exceeds its performance.

^(Quote from said shoot out)

^^^^^This is hilarious . It depends on the USB connection!
Edited by James-uk - 4/12/14 at 5:27pm
post #2572 of 3374
Well my older MacBook's USB connection is kind of lame and yeah, I can agree with that observation.
post #2573 of 3374
Bring some double blind examples to the table and I'm all ears.
post #2574 of 3374
How does one do blind experiments with DACs exactly? And especially in the case where it gets plugged into 2 different connections?
post #2575 of 3374
Quote:
Originally Posted by miceblue View Post

How does one do blind experiments with DACs exactly? And especially in the case where it gets plugged into 2 different connections?

Google double blind test.
post #2576 of 3374
Quote:
Quote:
Originally Posted by James-uk View Post

At its best, the ODAC sound expansive, detailed, and precise in imaging. At its worst, the ODAC sounds closed-in, flat, dull, uninteresting, and with wooly bass (Class S). It depends upon the USB connection. Overall the ODAC is not as precise in rendering of sounds. This is where the comparable Modi exceeds its performance.

^(Quote from said shoot out)

^^^^^This is hilarious . It depends on the USB connection!

The one thing that makes his reviews suspect to me is he uses audio descrptions that should only apply to amps or headphones. I think he gets a bit carried away with himself. One distinguishing feature of one DAC he has described as having great vocals. Huh?

Also I do not think many would agree with the following statement:

All DACs have a readily identifiable and describable sound. We can listen to something and say "Ah, that's a Bifrost. Or that's a PWD2."

For what I see are obvious reasons, this is very likely not to be true. And listening tests published on the Internet support this opinion of mine. (I do not remember what periodical on the Internet I got this from. Audiophile?)

Oh yes, that USB comment is a little amusing. I think the author of that comment and others like it has some explaining to do. IMO USB used to be a problem with audio. Other than bandwidth considerations,
this has no longer been the case. Still, now you have USB 3.0 now to consider for bandwidth.

I do agree that there are some aspects of the sound experience that cannot be accurately measured as such, at least for now. But measurements are a very good place to start. And if you only considered objective measurements, IMO you still would end up with a good piece of gear.
Edited by r010159 - 4/12/14 at 6:24pm
post #2577 of 3374
Quote:
Originally Posted by James-uk View Post

Quote:
Originally Posted by miceblue View Post

How does one do blind experiments with DACs exactly? And especially in the case where it gets plugged into 2 different connections?

Google double blind test.
I didn't find anything that tells you how to do the tests though....there's a bunch of results for the results of the tests though. XD
Quote:
Originally Posted by miceblue View Post

This might be a stupid question to ask, but is there a relatively easy way to do A/B comparisons between DACs?
Quote:
Originally Posted by m2man View Post

You can do it with some pro audio gear. Something with spdif in and 6 spdif out. This feeds two DACs. Then you go to one amp with different inputs and can change one the fly. It's too spendy to do cheaply. You just need a crazy pro audio friend. PM me. One of the Seattle meet regulars has this gear. He set up my PWD and his v800 this way.
post #2578 of 3374
Quote:
Originally Posted by James-uk View Post

Assuming v800 meets transparency criteria you are on!

Define transparency in a precise way and take a look at its specs here:  http://www.violectric.de/Pages/en/products/dacv800.php  If I agree to your definition then we'll set it up next time I'm in the UK (june) or if you're in Europe.  For the amp I propose a First Watt F5.  And we both bring the money in cash and put it down before starting.  Fair warning:  I own both as well as a HD-800 and trust me, I can tell the difference.  A similar bet already scored me a bottle of Yquem '89 but I'll be happy to accept your money and enrich my cellar some more.

post #2579 of 3374
Quote:
Originally Posted by James-uk View Post

Assuming v800 meets transparency criteria you are on!


i saw their specs page. they seems to be doing THD with -1dbfs... that's not very nice is it?

post #2580 of 3374
Quote:
Originally Posted by James-uk View Post

I find head fi so frustrating. The only thing that we need to be concerned with now is the transducer . Spend your money on music and headphones not dacs/ amps. If the odac/O2 can give the volume you need then you can move on from the amp/dac conundrum! I put money on the fact that the hd800 will sound the same on the O2 /odac as any transparent TOTL dac/amp in 1000( insert any year) years time. The transducer is the sound!!!!

 

 

 

That, and the ear pads. This is purely an anecdote.
The pads of my old headphone is so worn that it fell off. The effect is immediate. You notice the sound being thin and not musical and all that.
New pads. Voila. Good as new.

I thought I could identify the difference between odac and fiio e10 . These two dacs measures well ( odac is better numerically of course, but e10 fits my applications as well) and I am quite confidently say if you do a proper double blind test on me, I would not be able to differentiate the both of them consistently with my current headphone.
The pads on the other hand though, you have to be deaf to not be able to tell if it is working or not.

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphone Amps (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › O2 AMP + ODAC