[thecrow]

I'm thinking about getting the O2 as an amp for my aune t1 as I just got myself a pair of alpha primes that is measured at 47 ohm I think it was. And in the alpha prime thread people talk about them liking a good amp.

So my question is What would be the optimal gain selection be ? The standard 2,5x-6,5x ?

I had a similar question when I bought my Odac and O2 from Jdslabs.

John told me that the gain options should primarily come down to the voltage of the dac/source. For the Odac tgey recommend the 1x/3.5x option. You can see a little info on the Jdslabs website when you customise your Odac and your at tge stage of choosing the gain option. There's a little write up there.

However to confirm just email John at Jdslabs. His customer service is great.

And if you're looking to buy from them don't forget about the free engraving they do.

 

[Draulius]

Which headphones would be a better choice for this DAC/Amp, the AKG K712 Pro or Audio-Technica ATH-AD2000?
 
I'm guessing it's the former since people say it benefits more from an amp, and it's less sensitive so you get more room on the volume control. Am I right to think this?
 
Not that either would sound bad with it, but I can only pick one.

 

[JacobLee89]

  Which headphones would be a better choice for this DAC/Amp, the AKG K712 Pro or Audio-Technica ATH-AD2000?
 
I'm guessing it's the former since people say it benefits more from an amp, and it's less sensitive so you get more room on the volume control. Am I right to think this?
 
Not that either would sound bad with it, but I can only pick one.

 
The O2 is a very "plain" amp, but does this "plain" in the best possible way for such a price point. So the question is more of what type of sound are you looking for?
 
As for sensitivity, do you mean how much power it requires? I ask this because the K712's are known to be pretty power hungry. If we're going by impedence, the K712's are 62 Ohms whereas the AD2000 are 40 Ohms. Lower resistance generally means higher sensitivity.
 
That doesn't mean much since mine are HD650's, which are 300 Ohms, and still gets stupid loud at 12' oclock, with x1 gain on the O2.
 
However, if you could only pick one. Go for the K712's , they work well across a variety of music.
 
I would recommend trying other headphones out first before making such a decision. are there any local stores around where you can audition headphones?

 

[AlanU]

  Which headphones would be a better choice for this DAC/Amp, the AKG K712 Pro or Audio-Technica ATH-AD2000?
 
I'm guessing it's the former since people say it benefits more from an amp, and it's less sensitive so you get more room on the volume control. Am I right to think this?
 
Not that either would sound bad with it, but I can only pick one.

The 02 amp can very likely comfortably run majority of the headphones on the market. So it can easily cause most to become hearing impaired as far as volume is concerned
 
Headphones are so incredibly personal that you must audition. Also bring along the music genre you prefer. Also note short duration auditions will not easily indicate if you'll have ear fatigue.  These are just some things to make a note of .......
 
To my ears in general  I found the K712's over emphasizing the bass and treble. The mids were lost between the two. I do prefer the softer laid back presentation of the Hd650's. Ear fatigue is something you must really consider. However it all depends on your personal taste. 
 
This amp is not forgiving so if your source is bad the 02 amp will reveal it. If your headphones have the characteristics of being bright the 02 amplifier will gladly pierce your ears. 
 
The odac simply does the no frills conversion so it does it's task.  
 
test the amp/dac combo with as many HP and determine the sound signature you like. As far as volume is concerned you will have little problems in that category.  

 

[wildwood88]

Hi guys, I just bought hd600. My music source is basically from iPad Air 2 spotify premium. My question is do I need o2+ odac or just o2 amp is enough? I really no clue right now

 

[HotIce]

I don't think ODAC can decode the encrypted digital audio coming off an iPad Air 2 (one of my setups is like yours - iPad Air 2 with Spotify Premium).
I let the Wolfson DAC emit the line out via lightning to 30 pin cable, and feed that to an E12.

 

[wildwood88]

So u mean when you using iPad Air 2, u set with the Wolfson+E12 rattan O2 amp?

 

[HotIce]

The Wolfson is the DAC IC the lightning to 30 pin cable uses.

 

[Draulius]

   
The O2 is a very "plain" amp, but does this "plain" in the best possible way for such a price point. So the question is more of what type of sound are you looking for?
 
As for sensitivity, do you mean how much power it requires? I ask this because the K712's are known to be pretty power hungry. If we're going by impedence, the K712's are 62 Ohms whereas the AD2000 are 40 Ohms. Lower resistance generally means higher sensitivity.
 
That doesn't mean much since mine are HD650's, which are 300 Ohms, and still gets stupid loud at 12' oclock, with x1 gain on the O2.
 
However, if you could only pick one. Go for the K712's , they work well across a variety of music.
 
I would recommend trying other headphones out first before making such a decision. are there any local stores around where you can audition headphones?

 
I've read that the Audio-Technica AD2000's color the sound quite a bit. I don't like headphones that are too colored because it can make them sacrifice compatibility with certain music. I'd like a more natural sound signature, but with a good soundstage, useful for music and movies. And it sounded like the K712 Pro would be best for this. I've heard about the highs being shrill with certain amps, the O2 may be one of them, but that it usually goes away after burn-in.
 
I've used AD700's for years, which is considered a bright headphone, so I'd be surprised if I find these headphones fatiguing.

 

[WilliamLeonhart]

The shrills on my friend's K702 and Q701 never went away after burn in... AKG leans on being cold and analytical, and the O2 is too "plain" for me to enjoy with those cans. In fact I don't like those cans at all.

And these AKGs are really hard to drive... I've found them to be very amp-picky. My O2 doesn't do the job. However my (DIY) O2 is config-ed to be low-gain, I believe. I'm mostly using it with low-imp cans like Grado and ATH ADs.

 

[AlanU]

The shrills on my friend's K702 and Q701 never went away after burn in... AKG leans on being cold and analytical, and the O2 is too "plain" for me to enjoy with those cans. In fact I don't like those cans at all.

And these AKGs are really hard to drive... I've found them to be very amp-picky. My O2 doesn't do the job. However my (DIY) O2 is config-ed to be low-gain, I believe. I'm mostly using it with low-imp cans like Grado and ATH ADs.

k812 is on my short list. Much more musical than my hd800 and more open than my hd650. 
 
If you throw a tube amp at the akg headphones that'll tame those k702's / Q701's. Synergy is what  is the quest for musical enjoyment. This is a good example of how revealing 02 can pose a problem in matching components and headphones for musical bliss with NO ear fatigue. 

 

[Draulius]

The shrills on my friend's K702 and Q701 never went away after burn in... AKG leans on being cold and analytical, and the O2 is too "plain" for me to enjoy with those cans. In fact I don't like those cans at all.

And these AKGs are really hard to drive... I've found them to be very amp-picky. My O2 doesn't do the job. However my (DIY) O2 is config-ed to be low-gain, I believe. I'm mostly using it with low-imp cans like Grado and ATH ADs.

What kind of amp did you use for those headphones that had the shrill?

 

[AlanU]

  What kind of amp did you use for those headphones that had the shrill?

I know this question isn't directed to me but I've tested  the k712, Q701 and k612  and I was using  Bellari HA540 and tidal music stream. It was a setup at a local headphone shop. They all presented high pitch using a class A tube amp. Then I did a bad thing and put on a pair of K812's. There was a world of a difference compared to the other 3. Granted it's worth the substantial $$$ for those HP in the AKG line.So far those are the only AKG I'd consider for open headphones.
 
shrill wise I'd probably point fingers at the HP and DAC. The designer of the DAC can artificially increase sound stage and accentuate the high's and low's in cct design. The amp probably has the least  effect's on shrill. However whatever is in the chain of events has a cause/effect. 

 

[KeithEmo]

  I know this question isn't directed to me but I've tested  the k712, Q701 and k612  and I was using  Bellari HA540 and tidal music stream. It was a setup at a local headphone shop. They all presented high pitch using a class A tube amp. Then I did a bad thing and put on a pair of K812's. There was a world of a difference compared to the other 3. Granted it's worth the substantial $$$ for those HP in the AKG line.So far those are the only AKG I'd consider for open headphones.
 
shrill wise I'd probably point fingers at the HP and DAC. The designer of the DAC can artificially increase sound stage and accentuate the high's and low's in cct design. The amp probably has the least  effect's on shrill. However whatever is in the chain of events has a cause/effect. 

 
I tend to disagree with your comment about the tube amp. Tube amps are specifically noted for changing the character of the sound you pass through them (much more so than solid state amps). And, in general, tube amps tend to "smooth the sound" and so to "remove shrillness" - at least to a degree. Therefore, I would expect the tube amp to "de-emphasize any shrillness that may be present in the headphones you're listening to".
 
If you find a lot of AKG phones a little harsh or shrill, you might want to try a different brand - like HiFiMan's (planars tend to sound smoother and the opposite of shrill).
 
Considering the relative costs, it probably makes more sense to select a set of headphones you like to begin with, than to select a set you don't entirely like, then go hunting for an amp that will alter them into something you do like

 

[AlanU]

   
I tend to disagree with your comment about the tube amp. Tube amps are specifically noted for changing the character of the sound you pass through them (much more so than solid state amps). And, in general, tube amps tend to "smooth the sound" and so to "remove shrillness" - at least to a degree. Therefore, I would expect the tube amp to "de-emphasize any shrillness that may be present in the headphones you're listening to".
 
If you find a lot of AKG phones a little harsh or shrill, you might want to try a different brand - like HiFiMan's (planars tend to sound smoother and the opposite of shrill).
 
Considering the relative costs, it probably makes more sense to select a set of headphones you like to begin with, than to select a set you don't entirely like, then go hunting for an amp that will alter them into something you do like

Sorry I should have elaborated.
 
I was getting the fatiguing highs while using the Class A amplifier. I should have stated that this is due to the Headphones and NOT the amp.
 
I'm fully aware and appreciate the tube "roll off of freq" and change of holographic soundstage using tubes.
 
Your logic makes full sense.