O2 AMP + ODAC
Jan 22, 2014 at 6:33 PM Post #1,923 of 5,663

AsianBatman

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  Thank you so much for helping me :)

I have another question, I use the cable AUDIOQUEST Forest here, it does not come with ferrite, someone already did a test and feel the difference using ferrite?

   
It's possible there is no audible difference with some headphones and the included cables 1 foot length. Not sure.
 
A good test would be to try to use a longer length (like 5 feet) and try many different headphones. A closed and very revealing headphone is best.
 
I wonder what would happen if you placed 10 Ferrite beads on a USB cable 
biggrin.gif
confused_face_2.gif

 
Sorry, I'm easily amused..
 
Wait! No audible difference, requires volume matching and blind A/B test. All placebo!
 
EDIT: I just switched back between cables again and it's definitely very audible. Less so on my Magni and open headphones. On my DJ100 it makes everything seem more congested and warmer, like the lower mids are more forward and there is less treble. If anyone tests this, try it with any music that's warm and has a larger soundstage. I tried some Tony Bennett recordings and "Buena Vista Social club". Recordings that can often sound congested on a very warm headphone are best.
 
I bet a good headphone to test the differences would be the M50 or a bassier headphone that has slightly rolled off treble. Even the HD-650 might do the trick.
 
What it sounds like is what happens I connect my Headphone amps up to a MOV based surge protector, but even worse. Same symptoms almost.
 
EDIT 2: I just bypassed my USB hub (powered) and went directly to my computer. I switched between a 1' USB cable with ferrite core and a 1' USB cable with. It's stupid easy to tell the difference.  This was with the DJ100 and Headroom Micro Amp and ODAC. Similar results with HD-650. I highly doubt there can be an audible difference between USB cables even without the ferrite core (I know the whole 1s and 0s thing).
 
Hey, maybe it's the gold plating degrading the sound!!! 
biggrin.gif
 Only kidding...
 
I think this has to be the most bizarre thing I've encountered in years.
 

 
I didn't see any benefit of adding a ferrite bead usb to my setup. 
 
Jan 22, 2014 at 7:00 PM Post #1,925 of 5,663

adydula

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I don't think there are measurements comparing different USB or other power sources.
 
What you should be thinking about is how the ODAC was designed and does it meet the design criteria that that the designer was aiming for and that is a genuinely transparent DAC.
 
The O2 amplifier was created as a simple, low cost, minimalist design delivering 100% transparent performance into nearly any headphone. The ODAC takes the same minimalist approach to transparency.
 
One of the "several" areas that many people think that are necessary for high end DAC performance and or audio nirvana is the use of a elaborate and/or High Current Power Supply.
 
The ODAC disappears from your audio chain while using a PCs USB power supply.
 
Even if the PC's USB power is not 100% clean the ODAC circuitry is designed to handle that. Yes dirty USB power can degrade performance. The ODAC uses split digital and analog power supplies each with their own filtering and regulator. The analog supply has additional filtering and the critical reference voltages, and negative supply for the DAC chip, are further optimized.
 
I have tried several pcs of all kinds and brands and have used an o'scope to see the trash coming from the pc riding on the DC USB power...but the end result is it doesn't matter as long as the DAC can handle this junk and the ODAC does this nicely.
 
I have used powered USB hubs as well and I can not hear any detectable audio differences.
 
I would not sweat this at all...unless you have some real audible distortion or noise its not going to get any better or worse with most well designed USB pc power sources...
 
enjoy!
 
Alex
 
Jan 22, 2014 at 8:53 PM Post #1,926 of 5,663

glunteer

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  I don't think there are measurements comparing different USB or other power sources.
 
What you should be thinking about is how the ODAC was designed and does it meet the design criteria that that the designer was aiming for and that is a genuinely transparent DAC.
 
The O2 amplifier was created as a simple, low cost, minimalist design delivering 100% transparent performance into nearly any headphone. The ODAC takes the same minimalist approach to transparency.
 
One of the "several" areas that many people think that are necessary for high end DAC performance and or audio nirvana is the use of a elaborate and/or High Current Power Supply.
 
The ODAC disappears from your audio chain while using a PCs USB power supply.
 
Even if the PC's USB power is not 100% clean the ODAC circuitry is designed to handle that. Yes dirty USB power can degrade performance. The ODAC uses split digital and analog power supplies each with their own filtering and regulator. The analog supply has additional filtering and the critical reference voltages, and negative supply for the DAC chip, are further optimized.
 
I have tried several pcs of all kinds and brands and have used an o'scope to see the trash coming from the pc riding on the DC USB power...but the end result is it doesn't matter as long as the DAC can handle this junk and the ODAC does this nicely.
 
I have used powered USB hubs as well and I can not hear any detectable audio differences.
 
I would not sweat this at all...unless you have some real audible distortion or noise its not going to get any better or worse with most well designed USB pc power sources...
 
enjoy!
 
Alex

 


 

 
Very good your comment !

 
Jan 23, 2014 at 5:47 AM Post #1,927 of 5,663

conheo

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Here you go

http://www.amazon.com/Ravel-Piano-Concertos-etc-Thibaudet/dp/B0000042EU/ref=sr_1_2?ie=UTF8&qid=1390406694&sr=8-2&keywords=thibaudet+ravel

YouTube

http://m.youtube.com/watch?v=3vEKOCQPhQMh


Base on the youtube link...I try with HD650 / K601 / HD800 out from ODAC/O2, 2.5x gain, computer vol max, my room is very quiet and has a relax atmosphere :) . The music is playing nice with the volume knob around 9h30-11, at 11 is really loud for me. Let's just say i don't have any hearing problem as i go to doctor not long before. :)
 
maybe you use tooooo difficult headphone to drive......like vintage AKG or HE6 ? That why you need too much gain like this.
 
Jan 23, 2014 at 7:40 AM Post #1,928 of 5,663

nabwong

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Base on the youtube link...I try with HD650 / K601 / HD800 out from ODAC/O2, 2.5x gain, computer vol max, my room is very quiet and has a relax atmosphere :) . The music is playing nice with the volume knob around 9h30-11, at 11 is really loud for me. Let's just say i don't have any hearing problem as i go to doctor not long before. :)

maybe you use tooooo difficult headphone to drive......like vintage AKG or HE6 ? That why you need too much gain like this.


Without sounding like an A-hole, I explained before that the cd and the ripped cd is the one that has the low volume. :)

The YouTube link is fine. The spotify is fine. The cup-string-cup-headphone out is fine. I am not hearing impaired. I'm 35 with perfect hearing except when the wife is talking. Then all bets are off. :wink:
 
Jan 23, 2014 at 1:24 PM Post #1,931 of 5,663

jring

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Without sounding like an A-hole, I explained before that the cd and the ripped cd is the one that has the low volume.
smily_headphones1.gif


The YouTube link is fine. The spotify is fine. The cup-string-cup-headphone out is fine. I am not hearing impaired. I'm 35 with perfect hearing except when the wife is talking. Then all bets are off.
wink.gif

 
Can't help with the selective hearing in regard to your significant other which seems to be a common problem :wink:
But for the interestingly mastered CD - why don't you rip it to wav or flac and normalize it in audacity?
 
Joachim
 
Jan 27, 2014 at 3:00 AM Post #1,935 of 5,663

miceblue

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hi,


May i know STANDALONE ODAC can directly play with ipad air > cck > STANDALONE odac > amp ? (without any usb hub)

I've read that the ODAC works with the iPad, but I haven't heard anything about the iPad air. At least with my iPhone 4S, the power draw from the ODAC is too much and it doesn't work without a USB hub.
 

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