[sanakimpro]

 
for the hd650 favoring voltage over current, it's simply that it represents a 300ohm or more load. it's the same with any high impedance headphone the hd650 is nothing special on its own.
 
about all the crap to improve usb, if people are really concerned about how good usb can be, then they wouldn't use usb in the first place. get a soundcard and a dac with a nice coax or some optical stuff, that's how you improve usb IMO.
now back to the odac, I have never heard noises from sources with it, when I did on some of the other DACs I got in my hands(cheap stuff for the most). so while it's nothing scientific, it's good enough for me to believe I don't need to "improve" my usb.
now if you go on the shiit topics, you see that several people heard noises, and using a wyrd or any nonsense stuff like that does seem to improve on noise for most of those cases.
I read it as bad computer usb(try to get an usb card for 20$, or if voltage is the problem, get a powered hub also for about 20$), or as the DAC being crap(change DAC instead of trying to turn a donkey into a race horse). on the shiit topic they prefer to read is as amazing wyrd.
take your pick, in a sense everybody's right.

I agree with you. I have never had any noise from the ODAC/O2 combo with any USBs. Once, there was no sound at all, but that turned out to be a shorted/burnt USB cable. Replacing it with another spare resolved the issue.

 

[sanakimpro]

if you want the HD800 to sound exactly like the HD800 then the O2 /odac does that perfectly. If you want to somehow change the HD800 sound to suit a preference then it's open season, it's the Wild West , it's anyone's game and good luck to you and your wallet. Alternatively there is EQ . Ignore the Luddites that are stuck in the 70s and remember software is better than the hardware now so EQ IS the best/most accurate way to change/ alter/ improve/ the sound etc. more options exist than ever to achieve a perfect sound to you. My preference at the minute is iPhone as source(convenient) benchmark dac1 (because it accepts iPhone as source) into HD650(because it just sounds right most of the time without EQ to ME) my most accurate headphone is definately HD800 which sounds perfect from either odac/O2 or benchmark dac1. My taste however sways toward HD650 at the moment . Nobody can decide anyone else's taste for them but they can say without doubt that the O2/odac is perfectly transparent . The only decision to make therefore is which headphone is best and do I use EQ to 'correct ' that headphone to my taste .

I like and agree with your view. My approach is to keep the O2/ODAC and keep trying different headphones. It eliminates the need to worry about up-link / chain variables since I assume that the O2/ODAC is perfectly transparent (read the measurements by the designer and other enthusiasts).
 
Especially as a student, but one who really enjoys his music, I can't say how much money this approach has saved me.

 

[JacobLee89]

 
for the hd650 favoring voltage over current, it's simply that it represents a 300ohm or more load. it's the same with any high impedance headphone the hd650 is nothing special on its own.
 
about all the crap to improve usb, if people are really concerned about how good usb can be, then they wouldn't use usb in the first place. get a soundcard and a dac with a nice coax or some optical stuff, that's how you improve usb IMO.
now back to the odac, I have never heard noises from sources with it, when I did on some of the other DACs I got in my hands(cheap stuff for the most). so while it's nothing scientific, it's good enough for me to believe I don't need to "improve" my usb.
now if you go on the shiit topics, you see that several people heard noises, and using a wyrd or any nonsense stuff like that does seem to improve on noise for most of those cases.
I read it as bad computer usb(try to get an usb card for 20$, or if voltage is the problem, get a powered hub also for about 20$), or as the DAC being crap(change DAC instead of trying to turn a donkey into a race horse). on the shiit topic they prefer to read is as amazing wyrd.
take your pick, in a sense everybody's right.

 
Eh. My next DAC might as well be a DIY one. DIYAH has some very fun looking projects anyhow.
It's surprising how much use blu-tac has in soldering.

 

[AlanU]

  I agree with you. I have never had any noise from the ODAC/O2 combo with any USBs. Once, there was no sound at all, but that turned out to be a shorted/burnt USB cable. Replacing it with another spare resolved the issue.

 
I basically use an inexpensive well rated Belkin Gold usb cable for both my 2 channel and headphone rig.
 
I do however don't see a problem buying a "regen" for the sake of entertainment in this hobby.   
 
Since I own the 02 amp with a 9volt in the unit I do assume there is more potential for less noise due to having an extremely clean DC source as I unplug my wallwart from the equation. Wallwarts are not really known to produce clean DC compared to a battery.
 
For a while I was using my April Music stello u3 as a USB/spdif converter and that box literally made the sound "smoother/tubey" which at first threw me off. However using the Stello u3 to feed my DA160 Burson dac  > 02 objective amp the overall synergy was amazingly excellent. If I used my Concero HD as a USB/Spdif converter it suddenly became extremely neutral and almost on the side of cool but increased sound stage and more detail.
 
Thing about this audio world is that the entertainment of searching for better SQ is at the cost of thinning the wallet. However every hobby seems to eat $$ 

 

[KeithEmo]

   
I basically use an inexpensive well rated Belkin Gold usb cable for both my 2 channel and headphone rig.
 
I do however don't see a problem buying a "regen" for the sake of entertainment in this hobby.   
 
Since I own the 02 amp with a 9volt in the unit I do assume there is more potential for less noise due to having an extremely clean DC source as I unplug my wallwart from the equation. Wallwarts are not really known to produce clean DC compared to a battery.
 
For a while I was using my April Music stello u3 as a USB/spdif converter and that box literally made the sound "smoother/tubey" which at first threw me off. However using the Stello u3 to feed my DA160 Burson dac  > 02 objective amp the overall synergy was amazingly excellent. If I used my Concero HD as a USB/Spdif converter it suddenly became extremely neutral and almost on the side of cool but increased sound stage and more detail.
 
Thing about this audio world is that the entertainment of searching for better SQ is at the cost of thinning the wallet. However every hobby seems to eat $$ 

 
A battery is not only cleaner than most line-powered power supplies, but with a battery you also avoid the potential for power supply ground noise, and minimize the chance of certain other types of ground loops.
 
How adding a USB-to-S/PDIF converter to a DAC affects the sound depends mostly on the design of the DAC itself. If the DACs USB input is really good, then adding a converter with an equally good USB input won't help a bit. However, if your DAC is sensitive to jitter on its USB input (which many, especially older ones, are), then adding a converter that is less so can make a huge improvement. The purpose of the outboard converter is to correct a weakness in the DAC, so the results you get will depend on whether your DAC has that weakness to begin with and, if so, how well the outboard converter corrects it. (And there are a few converters out there that aren't themselves very good.)
 
Also note that some "converters" also perform other alterations to the signal - like upsampling (which I personally prefer to avoid).
 
However, you do need to be aware that some modern DACs have BETTER USB inputs than some converters - in which case adding the converter may actually degrade their performance.

 

[JacobLee89]

Sometimes it feels like a discussion on electronics, and it's an amazing experience to see so many facets that surrounds this seemingly amorphous hobby.
 
Would batteries suffer from voltage fluctuation once they fall below a certain capacity?

 

[jseaber]

  Sometimes it feels like a discussion on electronics, and it's an amazing experience to see so many facets that surrounds this seemingly amorphous hobby.
 
Would batteries suffer from voltage fluctuation once they fall below a certain capacity?

 
Voltage will fluctuate from any source, given a change in current. In other words, voltage can fluctuate even from a full battery. 
 
Designers expect power supply voltage changes. We add filters to ensure adequate ripple rejection at the amplifier

 

[Draulius]

I just got my ODAC/O2 in the mail. I set it up using the provided cable and power jack, then plugged my headphones in. I restarted my computer and went into my sound settings to make sure everything is in working order, which it should be. But when I play any audio it only comes out on one side of the headphones, the left. I checked the balance settings but both L and R are at 100.
 
Anyone know what the issue might be?

 

[sanakimpro]

  I just got my ODAC/O2 in the mail. I set it up using the provided cable and power jack, then plugged my headphones in. I restarted my computer and went into my sound settings to make sure everything is in working order, which it should be. But when I play any audio it only comes out on one side of the headphones, the left. I checked the balance settings but both L and R are at 100.
 
Anyone know what the issue might be?

Perhaps your TRRS connector is not compatible with the O2/ODAC? I use the two ring ones and they're ok.
Else, perhaps contact the manufacturer and get a replacement, I guess.

 

[Draulius]

  Perhaps your TRRS connector is not compatible with the O2/ODAC? I use the two ring ones and they're ok.
Else, perhaps contact the manufacturer and get a replacement, I guess.

I'm connecting with a AD700 using its stock cable (3.5mm). It worked on the Schiit Fulla so I'm not sure why it wouldn't work with this. I did e-mail their support however.

 

[sanakimpro]

  I'm connecting with a AD700 using its stock cable (3.5mm). It worked on the Schiit Fulla so I'm not sure why it wouldn't work with this. I did e-mail their support however.

Hmm, my friend experienced that with his Sony MDR 1RNC (3 rings at the jack), but solved it by wiggling the jack a but outward. Perhaps you can try that and see if that fixes it temporarily?
Cheers!

 

[KeithEmo]

   
Voltage will fluctuate from any source, given a change in current. In other words, voltage can fluctuate even from a full battery. 
 
Designers expect power supply voltage changes. We add filters to ensure adequate ripple rejection at the amplifier

 
Exactly.
 
And batteries can even produce noise - in the form of random hiss type noise.
 
However, batteries pretty well never generate hum....

And, since a battery doesn't require any sort of electrical connection "to the grid", it is the perfect "floating" supply.
(Although that's not to say that a battery operated headphone amp or phono preamp can't pick up hum directly through the air or through it's interconnects.)
 
Also, different types and capacities of batteries vary widely in terms of their output impedance.
(AAA or 9V alkaline batteries aren't especially low in impedance, but some rechargeable LiIon ones are quite good, and small lead-acid cells are usually good.)

 

[castleofargh]

 

  Perhaps your TRRS connector is not compatible with the O2/ODAC? I use the two ring ones and they're ok.
Else, perhaps contact the manufacturer and get a replacement, I guess.

I'm connecting with a AD700 using its stock cable (3.5mm). It worked on the Schiit Fulla so I'm not sure why it wouldn't work with this. I did e-mail their support however.

don't you have other headphones/IEMs, usually we all have at least some crap ear buds that came with some DAPs or cellphones. that way you can know for a fact if the problem comes from the DAC and send it back for repair/change.

 

[Draulius]

 
don't you have other headphones/IEMs, usually we all have at least some crap ear buds that came with some DAPs or cellphones. that way you can know for a fact if the problem comes from the DAC and send it back for repair/change.

It is a problem with the DAC. They are already sending a replacement.

 

[Draulius]

Is there any downside to having a 1/4in output on the ODAC/O2, like 1/4in adapters adding distortion?