[Jimster480]

No, you're correct...except his amp is the Objective2 (O2) and his DAC is the ODAC. I got mine from JDS Labs. It sounds great and I'm quite happy.

So the O2 amp is different? Because the design only is for the ODAC itself right? Or is it for both because when I looked at JDS labs it looked the same as the O2

 

[adydula]

The O2 amp is the "O2" amp.
 
The ODAC is the "ODAC".
 
Both are totally standalone and can be used separately or together.
 
Vendors that sell the O2, and ODAC separately and some have put the two in the same case etc...
 
I believe JDS sells a O2 and a O2 + ODAC Rev B, as well as a bunch of other stuff.
 
Alex

 

[Jimster480]

  The O2 amp is the "O2" amp.
 
The ODAC is the "ODAC".
 
Both are totally standalone and can be used separately or together.
 
Vendors that sell the O2, and ODAC separately and some have put the two in the same case etc...
 
I believe JDS sells a O2 and a O2 + ODAC Rev B, as well as a bunch of other stuff.
 
Alex

Ah alright that makes sense.
They are both designed by the same guy right? These are "his specs" as I have seen some sites tout am I correct?

 

[adydula]

You should go over to his blog site and do some reading.....
 
Alex

 

[U-3C]

You should go over to his blog site and do some reading.....

Alex

Just due to the nature of said blog, make that..."a lot of reading."

 

[Jimster480]

Just due to the nature of said blog, make that..."a lot of reading."

Where is that?

 

[Arkady Duntov]

Where is that?

He's banned here but use Google to search for 'NwAvGuy'.

 

[dukefx]

Or RocketScientist on diyaudio

 

[Arkady Duntov]

Or RocketScientist on diyaudio

Thanks. I didn't know that.

 

[MrMateoHead]

  There is finally an independent set of O2 measurements at:
 
http://www.neurochrome.com/o2-headphone-amp/
 
http://www.diyaudio.com/forums/headphone-systems/302852-o2-measurements-review.html
 
You can take a look and see how it measures objectively from an engineer who has an analyzer to do it correctly.
 
The person is an engineer and has designed a high end headphone amp and is selling it as well.
 
To make this up and above board the engineer states this in his article.
 
Alex

 
Wow - Its great to see such a detailed and somewhat "critical" review of the O2. Thanks for the links.
 
The "dramatic rise" in THD at higher output powers is basically true of any amp - they all have their "sweet spots", and they also sound like s*** when playing out of their performance envelope. That said I've never turned my volume knob much past noon using HE-400s, which are my least efficient headphones. I'm pretty sure I've never clipped a home or car amp either, since I generally can't stand it when the volume starts to hit 80 dB and beyond. So, I try real hard not to worry when an amp distorts at maximum volume and beyond. I'm actually quite impressed that the O2 provides essentially all its usable/rated power at less than 0.01%. That's better than most home AV receivers I read about.
 
But it would be nice if someone can explain to me why I should or should not care about intermodulation distortion. That and it would be nice to see the result when on AC power, since I'd venture that MOST O2 users stay plugged in, like me!
 
I've never thought that the O2 was the end-all be-all amp for headphones in the world, but I certainly don't feel that other amps will be a resounding unimpeachable improvement over an O2 playing within its performance envelope with normal headphones at reasonable (e..g 60-80 dB) volumes. Call me jaded - I just seek out the power I think my speakers need to hit a SPL in my room, then add 3-10dB if I can afford it! If you want to change the sound, you start by changing the speakers, IMO. That said I can't lie, at least in the case of AV receivers, I convinced myself that an Onkyo amp sounds "lean", my old Yamaha a little "warm". Don't know why, and don't know if I'd still think so in a blind / controlled test.
 
I can say I've heard the battery-drain "pulsing" - its bad, and with no low battery indicator, the first time I heard it I thought I'd broken something. Then again I tend to leave mine plugged in, going on battery once in awhile for the sake of cycling them. Considering how expensive most "audiophile" headphone amps are these days, I happily accept that flaw since the price is reasonable.

 

[turkayguner]

Hello guys,
 
How does the combo do with a Shure SE846? Currently I prefer the iPad mini 4, iPhone 5s and Macbook Air's plain headphone out over my Apogee ONE, which makes me sad. I love the Apogee ONE's recording audio features so much, and its portability. Mainly, the bass was so problematic when I pair my SE846 (also my ATHM50x) with Apogee ONE, I was not sure why and digged up the internet. Found that the output impedance of an amp is very important to match the impedance of the headphone. Those articles etc led me here to the O2/ODAC thread. I need your opinions before I make my purchase.

 

[adydula]

Mr MateoHead...
 
Just an FYI...you can follow the discussion with Tom the designer of the HP1 amp over at DIY in the headphone section.
 
Also AGDR might send his O2 Booster Board out for a similar analysis...
 
You can ask Tom directly about the IMD concern as well....
 
Alex

 

[Jimster480]

  Hello guys,
 
How does the combo do with a Shure SE846? Currently I prefer the iPad mini 4, iPhone 5s and Macbook Air's plain headphone out over my Apogee ONE, which makes me sad. I love the Apogee ONE's recording audio features so much, and its portability. Mainly, the bass was so problematic when I pair my SE846 (also my ATHM50x) with Apogee ONE, I was not sure why and digged up the internet. Found that the output impedance of an amp is very important to match the impedance of the headphone. Those articles etc led me here to the O2/ODAC thread. I need your opinions before I make my purchase.

Depends on how much you are willing to spend? The FiiO K1 is quite good for a low price if you just want to try out something better.
But this ODAC/AMP is one of the best rated things on this page and multiple Audiophile friends of mine have recommended it to me as its price/Sound Quality ratio is astounding.

 

[turkayguner]

I will buy the ODAC and the O2 seperately. But which gain setup do I need for my headphones? I have HD650 (300 ohms), ATHM50x (38 ohms) and Shure SE846 (9 ohms). "1x - 2.5x" or "1x - 3.5x" or "1x - 6.5x" ?

 

[turkayguner]

 
Depends on how much you are willing to spend? The FiiO K1 is quite good for a low price if you just want to try out something better.
But this ODAC/AMP is one of the best rated things on this page and multiple Audiophile friends of mine have recommended it to me as its price/Sound Quality ratio is astounding.

I do not want something just a tad better, I want the best for the money. The best for my current headphones actually.