[forsberg]

I've been reading nwavguy's blog and I agree with his scientific approach to sound quality, and the impression is that the O2 amp/dac is "perfect" in the sense that it doesn't change anything from the original signal other than conversion to analog then amplify.

But, how do things like soundstage get measured?

 

[headwhacker]

I've been reading nwavguy's blog and I agree with his scientific approach to sound quality, and the impression is that the O2 amp/dac is "perfect" in the sense that it doesn't change anything from the original signal other than conversion to analog then amplify.



But, how do things like soundstage get measured?

 


soundstage is a subjective term and I don't think it can be measured.

 

[forsberg]

I've been reading nwavguy's blog and I agree with his scientific approach to sound quality, and the impression is that the O2 amp/dac is "perfect" in the sense that it doesn't change anything from the original signal other than conversion to analog then amplify.



But, how do things like soundstage get measured?

 


soundstage is a subjective term and I don't think it can be measured.

That's what I want to find out, is how soundstage translates to measurements. It is impossible for two identical waves to enter your ears but have narrow vs wide soundstage. There has to be some differences.

 

[Solrighal]

While I have a very hard time understanding why anyone would care to use O2 with some tablet etc, even ignoring that, why isn't all of this info on the sellers pages so everyone understands what they are getting into.. but yeah sure you can always clip a resistor..

Anyways, I've rarely need more than unity gain with any of my headphones. Atleast it's better quality in theory, isn't that why we use O2 anyway..

This is exactly how I see it. There's another manufacturer in Europe who's making pretty much the same thing (with some useful variables thrown in) and when you visit his site he does explain why someone would choose different gains and for a small fee allows you to select your choice. Information is power. And I also agree that, since the whole point of the O2 is it's inherent transparency, it surely makes sense that using as little gain as possible would be the best way to maintain the 'Straight Wire' ethos.

That's what I want to find out, is how soundstage translates to measurements. It is impossible for two identical waves to enter your ears but have narrow vs wide soundstage. There has to be some differences.

I'm definitely no expert on technical matters like this but isn't it the case that the actual headphone used determines the soundstage? I mean, when I switch between my Q701's and my M-100 all aspects of the sound change but in particular it's the soundstage which is markedly increased. I haven't changed any other hardware or software. It's just the way the cans are designed. Feel free to shoot me down.

 

[MrMateoHead]

   
While I have a very hard time understanding why anyone would care to use O2 with some tablet etc, even ignoring that, why isn't all of this info on the sellers pages so everyone understands what they are getting into.. but yeah sure you can always clip a resistor..
 
Anyways, I've rarely need more than unity gain with any of my headphones. Atleast it's better quality in theory, isn't that why we use O2 anyway..

Well, I can tell you that both my $100 dollar throwaway Nokia phone and Nexus Tablet both sound excellent with the help of the O2; not quite ODAC awesome but hardly "bad" (no hiss, lots of detail, smooth). They have Internet radio apps and Pandora and what not, so can act as quite the jukebox when I am in the mood. Come to think of it, I don't know the last time I really heard a "bad" DAC, mostly issues I have are with background noise and lack of power. As an owner of IEMs, however, I get that the added sensitivity and isolation can be a curse - but to that I wonder why people buy super-powerful amps like the O2 to drive them, from which they only need 1/1000 to 1/100 of the power it produces. Sort of a mis-match.
 
Anyway signal "gain" is just another spec that is almost never provided in the audio world (or it is in the place of power, to make things more confusing). I bought a cheap amp to drive some speakers a month ago, in part because it specified, clearly, that it needed about 1V to reach its rated RMS power of 50 wpc. Good to know, since it is designed for multiple-zone audio applications, and the length of the cable run could be long enough to degrade the 2V signal I would be feeding it. Knowledge is power . . .

 

[gjc10212]

This is exactly how I see it. There's another manufacturer in Europe who's making pretty much the same thing (with some useful variables thrown in) and when you visit his site he does explain why someone would choose different gains and for a small fee allows you to select your choice. Information is power. And I also agree that, since the whole point of the O2 is it's inherent transparency, it surely makes sense that using as little gain as possible would be the best way to maintain the 'Straight Wire' ethos.
I'm definitely no expert on technical matters like this but isn't it the case that the actual headphone used determines the soundstage? I mean, when I switch between my Q701's and my M-100 all aspects of the sound change but in particular it's the soundstage which is markedly increased. I haven't changed any other hardware or software. It's just the way the cans are designed. Feel free to shoot me down.

Who?

 

[r010159]

[part of post deleted]

I'm definitely no expert on technical matters like this but isn't it the case that the actual headphone used determines the soundstage? I mean, when I switch between my Q701's and my M-100 all aspects of the sound change but in particular it's the soundstage which is markedly increased. I haven't changed any other hardware or software. It's just the way the cans are designed. Feel free to shoot me down.

 
This is an excellent observation! I agree. I think it is the headphones that determine soundstage.
 
BG

 

[Solrighal]

Who?

http://www.headnhifi.com/index.php?route=common/home

I apologise for the slip there, I thought I was in the JDS Labs thread and didn't want to advertise a competitor. Walter isn't technically in Europe but not too far off. I'd give his website 10/10 and Walter had to deal with me making a small mistake in my order but he dealt with it very well. Of course, I've yet to receive the goods so a final verdict will have to wait but I'm hopeful.

This is an excellent observation! I agree. I think it is the headphones that determine soundstage.

BG

Nobody ever says that, do they? Seems obvious to me and doesn't need abx double blind testing to work out.

 

[miceblue]

[part of post deleted]


I'm definitely no expert on technical matters like this but isn't it the case that the actual headphone used determines the soundstage? I mean, when I switch between my Q701's and my M-100 all aspects of the sound change but in particular it's the soundstage which is markedly increased. I haven't changed any other hardware or software. It's just the way the cans are designed. Feel free to shoot me down.

This is an excellent observation! I agree. I think it is the headphones that determine soundstage.

BG

Listen to something like the FiiO X5 or E12. Both are infamous for having a small soundstage. Then compare it to the O2, which is known to have a large soundstage.

 

[Solrighal]

Listen to something like the FiiO X5 or E12. Both are infamous for having a small soundstage. Then compare it to the O2, which is known to have a large soundstage.

I won't thanks but I take the point. To be fair though you're not really comparing like for like are you? What's the relative power outputs of all those amps?

 

[hekeli]

 
Well, I can tell you that both my $100 dollar throwaway Nokia phone and Nexus Tablet both sound excellent with the help of the O2; not quite ODAC awesome but hardly "bad" (no hiss, lots of detail, smooth). They have Internet radio apps and Pandora and what not, so can act as quite the jukebox when I am in the mood.

 
That's just silly to me and not very realistic usage scenario atleast for "desktop O2". Are you also using batteries? I'd never bother to carry O2 and something like HD800 around my house, then again I'm not the most extreme audiophile type anyway.. and who's to say ~3 volts wouldn't be enough for most headphones. I'm not saying 1/3x should be default, I think the main point was just describing these scenarios better for the consumer..

 

[miceblue]

Listen to something like the FiiO X5 or E12. Both are infamous for having a small soundstage. Then compare it to the O2, which is known to have a large soundstage.

I won't thanks but I take the point. To be fair though you're not really comparing like for like are you? What's the relative power outputs of all those amps?

I don't think power is really a factor for something sensitive like the M-100. Even if they all had the same power output, what would that mean?

O2:

Max Output 15 Ohms 337 mW Excellent
Max Output 33 Ohms
Max Output 150 Ohms
7 Volts RMS (19.802 Vp-p)
200+ mA peak current

X5:

Output Power 1 > 460 mW@16Ω THD<1%
Output Power 2 > 255 mW@32Ω
Output Power 3 > 28 mW@300Ω
MAX output voltage > 8 Vp-p
MAX output current > 150 mA

E12:

Output Power >880mW@32Ω
MAX output voltage 15.5 Vp-p
MAX output current 170 mA

 

[PTom]

I'm noticing some distortion on high gain running my Beyerdynamic T1, is this normal? If so is there a fix for this?

 

[MrMateoHead]

   
That's just silly to me and not very realistic usage scenario atleast for "desktop O2". Are you also using batteries? I'd never bother to carry O2 and something like HD800 around my house, then again I'm not the most extreme audiophile type anyway.. and who's to say ~3 volts wouldn't be enough for most headphones. I'm not saying 1/3x should be default, I think the main point was just describing these scenarios better for the consumer..

Mine is the battery-powered version. You must be imagining me dragging my amp around with headphones and a phone/tablet stuffed in my oversized pocket walking around the house. That is not the case. What is the case is that I actually use different sources with my amp, so I do in fact benefit from a high / low gain switch. Most "desktop" setups can be "set it and forget it", but I still like some flexibility. I did in fact value the portability of the thing, even if its not AS portable as other devices / amps.
 
Anyway, to each their own. There is a lot of documentation on the O2 and even if a consumer ignorantly bought an O2 without knowing what gain settings they really needed/wanted, I really doubt the stock settings would be THAT awful. Then again I wouldn't be one to buy a near 1-watt amp with a pair of IEMs in the first place, but that's just me. I bought some inefficient planars and ran them off (gasp!) my laptop first to see how far I could get with a lowly Realtek chip.

 

[chuck8403]

I'm noticing some distortion on high gain running my Beyerdynamic T1, is this normal? If so is there a fix for this?

From O2 blog:

THE GAIN RESISTORS: Before you solder in the four gain resistors by the gain switch, you might want to consider different gains than the approximately 2.5X and 6.5X default values. You want just enough gain so typical music plays loudly enough with your headphones and source and not much more. Extra gain means using less of the volume control’s range, more noise, more distortion, and makes accidental headphone damage more likely.