[AddisonTaras]

Hi
I got the DT990 Pro a few months back (Christmas), but I didn't get an amp with it.
They sound okay/decent, but man; I can just picture these things sounding so much better with an amp.
So, for the longest time I was looking at the E17 the most - with the O2 in the back of my mind every now and then.
Just lately I've been looking into the O2 more, hearing good things, how they're better than the E17 and they're not even that much more than the E17.
I was about to get it when I read that it sounds terrible without a DAC/needs a DAC to work/sound good?
(I apologize if I sound very ignorant, it's cause I am, LOL.)
So, I thought no problem, right?
Well, I only have so much money, and to get an O2+ODAC combo is 285$... so, that's kinda out of the picture now, and now I'm back to the E17.
Basically, can I run the O2 by itself without a DAC? Source being my computer (Mac desktop and PC laptop)
Should I save up for the O2+ODAC combo? (that's a lot of money, even anything past 100-120ish$ is too much for me)
Or should I just go for the E17?
I'm kinda thinking the E17 the most - just because it's been there since the beginning, seems the most simple and it's a Amp+DAC
Also another question: if I was to get the E17 for my DT990s; would I hear only a small difference, big difference, or HUGE difference?
 
 
I'd love to hear everyone's thoughts and if someone could answer my question on the O2 without a DAC.
Thank you!

 

[adamlr]

in my own personal experience, and keep in mind that many will disagree with me, a dac is the last thing you should worry about. hq music first, headphones second, amps third, and then if youve got some money left, spend it on a decent dac. i dont have the 990s but i do own the 770s, so im not entirely disconnected from your position.
 
so my vote would be to get the O2 and worry about getting an odac later when you find more funds for it. i use a pc (lenovo) laptop myself. laptops are notorious for having bad sound cards in them. yet, when i plugged my odac in for the first time i was somewhat disillusioned. i was expecting "night and day" and received no such thing. im keeping my odac largely for peace of mind, so i know i have a good d/a converter and can worry about other things. to be completely honest though, i just plugged my O2 directly into the headphone jack of my computer and it sounded absolutely fine. i doubt i would be able to tell the difference in a volume matched blind test...
 
im assuming your dt 990s are 250 ohm? id recommend getting an O2 and asking for unity gain and 2.5x. that way your set for whatever it is that your computers headphone jacks are outputting.
again, others may disagree, this is only my opinion, based on my experience with the O2, Odac and a different set of headphones. also, i have never used an e17.
best of luck
 
cheers

 

[AddisonTaras]

Quote:

in my own personal experience, and keep in mind that many will disagree with me, a dac is the last thing you should worry about. hq music first, headphones second, amps third, and then if youve got some money left, spend it on a decent dac. i dont have the 990s but i do own the 770s, so im not entirely disconnected from your position.
 
so my vote would be to get the O2 and worry about getting an odac later when you find more funds for it. i use a pc (lenovo) laptop myself. laptops are notorious for having bad sound cards in them. yet, when i plugged my odac in for the first time i was somewhat disillusioned. i was expecting "night and day" and received no such thing. im keeping my odac largely for peace of mind, so i know i have a good d/a converter and can worry about other things. to be completely honest though, i just plugged my O2 directly into the headphone jack of my computer and it sounded absolutely fine. i doubt i would be able to tell the difference in a volume matched blind test...
 
im assuming your dt 990s are 250 ohm? id recommend getting an O2 and asking for unity gain and 2.5x. that way your set for whatever it is that your computers headphone jacks are outputting.
again, others may disagree, this is only my opinion, based on my experience with the O2, Odac and a different set of headphones. also, i have never used an e17.
best of luck
 
cheers

 


Hey, thanks for responding.
Yes, my DT990s are 250 ohm.
With your DT770 and the O2 (or whatever other headphones you've used) did you hear a night and day difference? or was it only slightly better for you?
 
Also, another ignorant question:
What's "unity gain" and "2.5x"
Are those settings on the amp?
 
Also, I'm still not 100% sure if I should do it, because I've read a couple people saying that they get a distorted sound when they only have the O2? or maybe that there's was faulty? I don't know, I didn't get much detail out of it.

 

[adamlr]

Quote:

 


Hey, thanks for responding.
Yes, my DT990s are 250 ohm.
With your DT770 and the O2 (or whatever other headphones you've used) did you hear a night and day difference? or was it only slightly better for you?
 
Also, another ignorant question:
What's "unity gain" and "2.5x"
Are those settings on the amp?
 
Also, I'm still not 100% sure if I should do it, because I've read a couple people saying that they get a distorted sound when they only have the O2? or maybe that there's was faulty? I don't know, I didn't get much detail out of it.

1st paragraph: night and day? ill tread carefully and say that the difference wasnt night and day, but it was noticeable nonetheless. personally, i did feel there was an improvement, and it was large enough to justify the cost. dt 770s are said to improve greatly with amps. the better the amp - the better the dt 770s. having only used it with 3 amps (2 of which sounded virtually identical to me), im inclined to agree. i have never used 990s, but i imagine you wont get the full potential they have without using an external (more powerful) amp.
 
2nd: yes, the gain setting is by how much the inputed signal is being multiplied. the standard O2 (atleast when coming from jds labs like mine did) come with gain settings of 2.5x and 6.5x if you press the gain button. the higher the gain, the louder the signal will be. this is a very simplistic and incomplete explanation and by no means explains the workings of gain, volume, or output power. its just to give you a general idea. 
"unity gain" is a gain setting that doesnt multiply the inputed signal in the same way. instead of multiplying by 2.5x or 6.5x it remains on 1x. i dont understand how it works, but it does, and its meant for sensitive headphones or iems. on request, jds labs will send you an amp with different gain settings: either 1x and 2.5x, or 1x and 6.5x.
id like to take back my recommendation of chosing one over the other. i was just reprimanded on the O2 thread for talking such talk and so ill explain a little more, and leave the decision up to you.
the volume you get in the end depends on many things. the stronger the input signal going into your amp, the stronger it will come out at the output stage. so if for example, you want to use a portable player as your source, 6.5x gain may be necessary for you. if you intend on getting some "hard to drive" headphones in the future, 6.5x gain may be necessary for you.
whichever setting you decide on depends on the way you intend on using the amp.
 
3rd: distorted sound? how so?
from the head-fi glossary of terms:
"Distortion - Refers to a change in a signal away from its original form. The amount of distortion in audio equipment is measured as Total Harmonic Distortion (THD) or Total Harmonic Distortion plus Noise (THD+N) or Intermodulation Distortion (IM) in Decibels. The effects of distortion in audio equipment are many and varied and the relevance of degrees of distortion and types on what we are able to detect audibly is the subject of much debate."
 
the O2 should be silent. however, if the source is noisy or distorted, the O2 will output a noisy/distorted signal. perhaps get more details about that first? there are many possible causes for distorted/noisy sounds.

 

[mikeaj]

Do you ever wish you had more volume out of either computer?

 

[bada bing]

Quote:

Do you ever wish you had more volume out of either computer?

Volume isn't the only benefit from adding an amp. In the case of 1X gain, it isn't a benefit at all. The two electrical functions of an amplifier are voltage gain and impedance transformation. Just by virtue of presenting a higher input impedance to a computer sound card and a lower output impedance to the headphone drivers, an amp will be a benefit to the performance of both. In some cases, a negligible amount, but in many cases a noticeable and useful amount. Adding a "transparent" amp like the O2 to a computer audio chain can easily have some fairly obvious influence on the sound, depending on what's upstream and downstream. It isn't that the "transparent" amp is adding anything to the chain itself, it is that it is altering the performance of both source and driver by changing the impedance. The question of value in any particular case is hardly ever about "volume".

 

[mikeaj]

Of course volume is not the only benefit, but with something like DT 990 Pro (around 100 dB SPL / 1V, or 94 dB SPL / 1 mW... depends on who you ask—rather, test sample and procedure), it could be a determining factor on whether or not E17 is enough.  Some people with some music would want something hotter than what the E17 can do, in which case spending on a more powerful amp instead may be a better pick.  For example, E9, Schiit Magni, cheapest O2 builds, etc. are around $100.  For others, say E07K may be reasonable.
 
After all, $100-120 is already stretching the budget.
 
Before you even talk about sound quality (though whether there's as much there to discuss as many do, is another topic), you should at least make sure you have something with the proper inputs and outputs, form factor, features, volume.

 

[AddisonTaras]

Quote:

1st paragraph: night and day? ill tread carefully and say that the difference wasnt night and day, but it was noticeable nonetheless. personally, i did feel there was an improvement, and it was large enough to justify the cost. dt 770s are said to improve greatly with amps. the better the amp - the better the dt 770s. having only used it with 3 amps (2 of which sounded virtually identical to me), im inclined to agree. i have never used 990s, but i imagine you wont get the full potential they have without using an external (more powerful) amp.
 
2nd: yes, the gain setting is by how much the inputed signal is being multiplied. the standard O2 (atleast when coming from jds labs like mine did) come with gain settings of 2.5x and 6.5x if you press the gain button. the higher the gain, the louder the signal will be. this is a very simplistic and incomplete explanation and by no means explains the workings of gain, volume, or output power. its just to give you a general idea. 
"unity gain" is a gain setting that doesnt multiply the inputed signal in the same way. instead of multiplying by 2.5x or 6.5x it remains on 1x. i dont understand how it works, but it does, and its meant for sensitive headphones or iems. on request, jds labs will send you an amp with different gain settings: either 1x and 2.5x, or 1x and 6.5x.
id like to take back my recommendation of chosing one over the other. i was just reprimanded on the O2 thread for talking such talk and so ill explain a little more, and leave the decision up to you.
the volume you get in the end depends on many things. the stronger the input signal going into your amp, the stronger it will come out at the output stage. so if for example, you want to use a portable player as your source, 6.5x gain may be necessary for you. if you intend on getting some "hard to drive" headphones in the future, 6.5x gain may be necessary for you.
whichever setting you decide on depends on the way you intend on using the amp.
 
3rd: distorted sound? how so?
from the head-fi glossary of terms:
"Distortion - Refers to a change in a signal away from its original form. The amount of distortion in audio equipment is measured as Total Harmonic Distortion (THD) or Total Harmonic Distortion plus Noise (THD+N) or Intermodulation Distortion (IM) in Decibels. The effects of distortion in audio equipment are many and varied and the relevance of degrees of distortion and types on what we are able to detect audibly is the subject of much debate."
 
the O2 should be silent. however, if the source is noisy or distorted, the O2 will output a noisy/distorted signal. perhaps get more details about that first? there are many possible causes for distorted/noisy sounds.

 
I can't find the thread now
But I remember this guy saying he had an O2 and that it sounded distorted when it was connected to some thing he had and then to his computer. Then another guy highly recommended getting the O2 DAC.
Sorry this all sounds very undetailed/pointless, but I don't wanna buy something and then realize it sounds bad/doesn't work/make much of a difference.
Personally, I'm leaning towards the E17, but I'm a bit worried it'll be underpowered - but the fact that it's a amp/DAC makes me feel a bit better I suppose.
Like, I read one thread where a guy said that the DT990 Pro sounds awful unamped, and pretty much a night and day difference amped.
But then there are other people saying it's not that big of a difference.

 

[adamlr]

Quote:

 
I can't find the thread now
But I remember this guy saying he had an O2 and that it sounded distorted when it was connected to some thing he had and then to his computer. Then another guy highly recommended getting the O2 DAC.
Sorry this all sounds very undetailed/pointless, but I don't wanna buy something and then realize it sounds bad/doesn't work/make much of a difference.
Personally, I'm leaning towards the E17, but I'm a bit worried it'll be underpowered - but the fact that it's a amp/DAC makes me feel a bit better I suppose.
Like, I read one thread where a guy said that the DT990 Pro sounds awful unamped, and pretty much a night and day difference amped.
But then there are other people saying it's not that big of a difference.

i have found that many people fret and fuss about very small differences. a 5% improvement can sometimes be portrayed as 10x better and a 5% degradation can be referred to as a devastating downfall. i think that when on head-fi, and in life in general - take everything you hear with a grain of salt.
 
keep in mind that if the files your playing are of poor quality (ie. IN MY PERSONAL OPINION anything less then 320 kbps mp3, or atleast 256, but many will disagree), or bad recordings (thats to do with the recording itself and isnt under your control), good audio gear wont make them sound any better, and may well make them sound worse. other than that, many many reasons exist for distortion and noise.
 
you want my opinion? i think your getting very worked up over this. as mentioned above, cheaper O2 builds exist, like mayflower for example. why not try one of those? if you really want a dac aswell, why not go over to the e17 thread and ask them if they think it could work with your set up? agonizing over it wont do you any good, and if your anything like me, or many others around here, youll end up getting them both, plus many more audio related gear. thats why the head-fi greating is "sorry about your wallet".

 

[shadow419]

I've had the O2 I built for over a year now, and I used it for a long time with just the on board sound. It works just fine. You'll hear distortion using the O2 in a couple of cases.

1. The music has distortion
2. The headphones have distortion from playing too loud
3. The amp is distorting because the gain isn't set up properly.

Not everyone likes how the O2 sounds, but it's distortion numbers are ridiculously low

 

[AddisonTaras]

Thanks everyone.

I recently made a new discovery, the E12 - which I think I'm going to go for.
Before I get it though, does anyone think I should get a DAC with it?
Or is using my Mac/PC + the E12 good enough? Should I get the Fiio D3 with it? it's not that much money, but is it necessary?
Should I get a new sound card?

Sorry for so many questions and changing subjects/my mind on different amps!