[Francisk]

I always switch on my O2 or any other amp for that matter, before plugging in my headphone. 

 

[HaVoC-28]

I don't , my O² will celebrate his third year next month and it didn't harm any of my headphones

.
 
There is a little hump when switching off but nohting to bother with .

 

[MrMateoHead]

  Does anyone have any experience with the standalone ODAC plugged in with the computer? I have it hooked up with my Audioengine A2 desktop speakers, but the ODAC makes everything too loud. My system sound is always somewhere between 10 - 15, and music player around 50%. If I turn the A2 down too low, then the volume distribution between the speakers will be unbalanced. Anyone have any experience with this? 

 
Sounds mainly like the 2V output of the ODAC is too much for the A2's internal amps to handle (they are optimized for 1V or so?). Are you using the RCA or 3.5mm inputs? Not that it should make a difference, but you never really know.
 
1) I'd start by setting the A2 to wherever their balanced output is, then 2) use the music player to cut volume to reasonable levels. If I still couldn't get a good volume range, I'd 3) start trimming the windows volume down.

 

[Bananaheadlin]

I'm using the 3.5mm inputs. My music player is currently set at 50%, and Windows at 10%. It works great, but the only problem is that my web browser (and other programs such as Cortana) become much louder, because my speaker volumes are usually set to play my music at a comfortable volume, which is only outputting at 50% from the music player.  

 Any there any other (software or hardware) solutions that might work for this?

 

[Psalmanazar]

My ODAC+O2 combo is clipping with dynamically mastered recordings on my HD 650s both 1x and 3.5x gain with foobar outputting in WASAPI or ASIO in exclusive mode at 24-bit. It does not clip at even louder volumes in DirectSound but the DirectSound imaging is so much worse. The windows volume control still affects the DAC but this shouldn't be the cause of the clipping. Any possible solutions?

 

[castleofargh]

  My ODAC+O2 combo is clipping with dynamically mastered recordings on my HD 650s both 1x and 3.5x gain with foobar outputting in WASAPI or ASIO in exclusive mode at 24-bit. It does not clip at even louder volumes in DirectSound but the DirectSound imaging is so much worse. The windows volume control still affects the DAC but this shouldn't be the cause of the clipping. Any possible solutions?

sure it's clipping and not some freezes of sort from the computer, or some conflicts with another application trying to use the device? I can't think of something that would have a reason to clip in wasapi and not with directsound.
 
random stuff to look up, but shouldn't fit your situation if I understood it correctly:
is there a volume threshold making the clipping come or go? test both in foobar and on the O2.
you have the "prevent clipping according to peaks" choice in foobar?
remove all EQ or DSPs to check if they could be responsible for clipping or distortions.
asio would be asio4all, the best way to use it is to uninstall it, IMO.
wasapi, I never noticed a difference, but I would guess push is the proper method for the odac. should also not matter, but maybe try changing the buffer value for wasapy.

 

[bolmeteus]

How does the ODAC perform against the Behringer UCA202 DAC. What are the sonic differences? Thank you!

 

[raoultrifan]

nwavguy, the developer of ODAC, has an article on his blog with extensive tests done to UCA202 interface. Feel free to read his thoughts and compare specs and graphs from UCA202 with ODAC.
 
Basically, looks like UCA202 is the best bung for the buck, especially at this price.

 

[bolmeteus]

nwavguy, the developer of ODAC, has an article on his blog with extensive tests done to UCA202 interface. Feel free to read his thoughts and compare specs and graphs from UCA202 with ODAC.

Basically, looks like UCA202 is the best bung for the buck, especially at this price.

this is probably stupid of me to not know new guy developed the ODAC, I did not read his excellent review on the uca202 completely.. Going there now!!
I have the uca202 and it is mind blowing for the price.

 

[B-Rayn]

Would the O2 amp be a good match for a dap like the Fiio X5ii?  I am new to headphone amps and am finding mixed reviews. Some say an O2 amp may not be noticeable others say it will increase clarity.
Or does it just depend on headphones used?

 

[Smugsie]

  Would the O2 amp be a good match for a dap like the Fiio X5ii?  I am new to headphone amps and am finding mixed reviews. Some say an O2 amp may not be noticeable others say it will increase clarity.
Or does it just depend on headphones used?

 
I don't have any experience with the 2nd gen X5, however I would say that my X5 1st gen would sound pretty much the same when I use them alone compared to using it with an O2. 

Some headphones benefit from more power being pushed into my headphones. For example I get a bit more treble when pushing more power into the Q701's with an O2, which of course leads me into thinking that the sound is clearer.

Try and see if your headphone is listed here and use the impedance vs frequency graph option: http://www.headphone.com/pages/build-a-graph

 

[B-Rayn]

   
I don't have any experience with the 2nd gen X5, however I would say that my X5 1st gen would sound pretty much the same when I use them alone compared to using it with an O2. 

Some headphones benefit from more power being pushed into my headphones. For example I get a bit more treble when pushing more power into the Q701's with an O2, which of course leads me into thinking that the sound is clearer.

Try and see if your headphone is listed here and use the impedance vs frequency graph option: http://www.headphone.com/pages/build-a-graph

Thanks very much for the reply and help.  

 

[Psalmanazar]

WASAPI push mode and nothing else in the surge protector but my Thinkpad and the O2 wart prevents the O2 from clipping the ODAC.. Everything else but DirectSound clips. Strange.

 

[MrMateoHead]

  WASAPI push mode and nothing else in the surge protector but my Thinkpad and the O2 wart prevents the O2 from clipping the ODAC.. Everything else but DirectSound clips. Strange.

I would try using different media players - does it clip when using Windows Media Player as well? How about VLC?
 
Are you 100% positive that the recordings you are listening to don't clip? (You can use something like Audacity to take a look). I couldn't stand the grating, "etched" sounding new Grimes CD at first, through virtually any speaker I own. I am getting over it because I still like the music, but album level clipping is an issue over and above DAC or AMP clipping. Worth it to check, and be sure!

 

[Psalmanazar]

  I would try using different media players - does it clip when using Windows Media Player as well? How about VLC?
 
Are you 100% positive that the recordings you are listening to don't clip? (You can use something like Audacity to take a look). I couldn't stand the grating, "etched" sounding new Grimes CD at first, through virtually any speaker I own. I am getting over it because I still like the music, but album level clipping is an issue over and above DAC or AMP clipping. Worth it to check, and be sure!

There was no red in Audacity. I wasn't listening to smashed crap when I noticed it. I noticed the clipping on a -2 peak, 11 db of dynamic range, -20 RMS average keyboard track listening on HD 650s. I just tried it with "event mode" with some 5 db of dynamic range pop, -.05 peaks and yeah no clipping on my HD 25s as it doesn't have to be amplified as much but it clipped with dynamic classical music and 80s metal.

It's not the player, it's the output from the ODAC (powered from a USB port) clipping the O2 amp due to poor opamp design choices from nwavguy. He stuck the volume pot between the stages. It clips even on 1x gain sometimes. Then you have JDS Labs poor choice of letting the windows volume slider control the volume (power) to the ODAC despite that potentially allowing it to clip the O2 as they didn't set the firmware in the ODAC to bypass that when the DAC is set in exclusive mode with the standard drivers (ASIO and WASAPI) that bypass the Windows DirectSound mixer/resampler. This clipping is different from dirty USB power making the bus-powered ODAC not sound very good. This is the same clipping that comes up in 6.5x on the O2 when that gain setting is used with a normal 2 volt source like the ODAC.