O2 AMP + ODAC - Page 59

It sounded like I still got a slight scratch on battery via the YouTube link. Not particularly consistent. Plugged the adapter back in - no worse, no better.

 

I can't believe people actually listen to that stuff! Its almost painful.

 

I've got some Royksopp going in Foobar (the alcoholic) and I don't get any scratching at all. I still wonder if there is a noise issue that might be a part of the windows drivers -> browser -> youtube link.  If Sines are scratching in Foobar WASAPI for him I suppose there is little left to blame but the pot.

Edited by MrMateoHead - 2/12/13 at 8:28pm

Has anyone tried hitting the pot with compressed air? I might give that a try tomorrow.

Alright, my youtube link sucks.. for testing this problem. Try a sine wave around 50 hz

http://www.realmofexcursion.com/downloads.htm - just click on em.

 

You misunderstood me. I couldn't hear it on either ac or battery.. I actually can't hear it at all on the youtube video, it turns out. But I hear it with my sine gen and other places. It's real hard to pick out on music right now.. at other times it sticks out so much that it's very obvious even with music. 

 

Again, it has nothing to do with the power.

Try my new link, my youtube video wasn't ideal.

 

Also, I actually get a little distortion in the left channel too, just not as much as the right.

Edited by chrislangley4253 - 2/13/13 at 1:26am

I am now a proud member of the O2 / Odac club !!! Got my O2 combo last night. Feels good man.

yes it does!

 

just plugged in my odac and o2 for the first time myself and im loving it!

i did have some clicking noises, but i switched to a different usb outlet and it seems to have done the trick. 

 

now, i have a question, based on what i read here on head-fi, analog volume control has channel issues, where one should have the volume pot at a "9 o'clock position" or higher, in order to avoid said issues. right now thats now problem, but in the not so distant future i plan on getting new headphones and these will be very sensitive, very efficient ones and i suspect the "9 o'clock position" will be too much for them and will force me to reduce the volume and enter into channel imbalance land. 

my question is this: if i reduce volume via electriq on foobar, would this be the same as digitally lowering volume through my computer (which i understand can degrade sq, although i admit i have my doubts...)? 

 

 

edit: rather handsome i must say =]

 

Edited by adamlr - 2/13/13 at 7:09am

You have two options really.  You can use software volume control, or you can use unity (X1) gain for one of the gain positions on the gain switch.

i have the standard gain settings: X2.5 and X6.5. so no X1 for me im afraid. unless one can adjust this simply from the inside? im no diyer...

 

Channel imbalance is a common problem with inexpensive pots. Even so, my O2 doesn't have any (audible) imbalance and I almost always set my O2's volume below 9:00.

 

 

Change from 2.5x/6.5x to 1.0x/2.5x requires cutting 4 leads to remove two resistors from the circuit.

 

Edit: Spelling correction

Edited by HamilcarBarca - 2/13/13 at 9:39am

1) thats good to know, thank you.

2) sounds very D.I.Yish to me, i dont think ill mess about with things like that.

 

right now i have the volume pot at just about 10 o'clock, so its all good. i guess ill wait and see what happens when i get my next headphones. hopefully ill discover, like you, that no channel imbalance is audible. worst comes the worst ill look for a guide on how to cut those leads the way you suggested. thank you very much

A little diy'ish, but extremely simple to do if you indeed go that route.  I soldered little sockets to "plug" in the gain resistors.  This way I can adjust the gain whenever I need to without having to resolder anything.  

If the ODAC is running at 24bit then the computer's volume control won't degrade audio. The ODAC defaulted to 16bit on my Vista laptop. Ideally it should be 24bit 44Khz. Higher sample rates can cause audio degradation, and in any case will cause upsampling, which defeats the purpose.

If foobar is bypassing the standard drivers then you'll need to make sure some other way that it's not running at 16bits.

And yes, reducing volume would solve your problem. I would advise using the system volume since otherwise your sensitive earphones might suddenly find themselves pumping 120db of audio in to your ears curtosy of a web advert or accidental video. I don't beleive there is any need to bypass the system drivers. Bit Perfect and all that is just Bit Nonsense in my view. You won't get any discernible increase in audio quality.

Alternatively get one of these :

http://www.head-fi.org/t/627755/short-positive-review-iluv-headphone-2-way-splitter-with-dual-independent-volume-controls

They are quite useful.

If you want to run your O2 off a low power dap (like an ipod or clip+ etc) then it;s probably best to go for 1x/6.5x. 2.5x can be too little for less sensitive or high ohm headphones when running off a low voltage source, especially if you are EQing in bass (which can lower the source's overall volume to accomodate the bass bump without distortion).

I would also advise against 'the snip' if you don't really know what you are doing. It's very easy to get wrong.

"the snip" just made me literally laugh out loud =]

 

i did set the sample rate to 24/44khz. though i noticed i can go as high as 24/96. either way, all my files are 320kbps mp3s anyway...

i never eq the bass up, only eq everything else down. no distortion - ever.

 

i noticed there are options for eq on the odac menu. bass boost for example. why would i want do eq with my dac??

 

 

thank you everyone for your help. is ther anyone else that noticed/didnt notice channel imbalance when using the O2? especially if paring with a sensitive headphone and setting the volume knob to under "9 o'clock"? this is really what im asking i think. and if someone did have some issues - what did you do?

He he.

I always use the bass boost because most of my headphones lose bass under 80Hz, so I bass boost about 6-9 db according to the headphones at 50Hz. Also I use flat headpdhones, partly for the accuracy but also because they have superb distortion handling, so I can EQ without fear to get that bass that I want while having the benefit of flatness elsewhere. I would prefer to bass boost at 30Hz, 12db, but no such option.

This solves the problem that Windows Media Player and so many others distort horribly in the EQs, whereas the Bass Boost doesn't and also provides the bass boost system wide, handy for spotify.

If you consider loudness curves then it;s very handy to be able to bass boost, especially if you listen less loudly. I'm a loud listener, but since I gave up caffiene I've suddenly found myself turning the volume right down. I suspect I;m getting a more accurate treble presentation from my etymotics also, which are otherwise known for their rather strong treble.

 

True dat. Add in a bit more bass boost for commuting, because headphones only isolate from mids and highs in most cases.