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Review: JDS Labs O2 (Black edition) + O2/ODAC discussion - Page 14

post #196 of 498
Quote:
Originally Posted by tdockweiler View Post

Quote:
Originally Posted by miceblue View Post

This is probably going to end up sounding like a really dumb question, but does the DAC really make a difference in sound quality? I only have 1 dedicated DAC (ODAC) and it doesn't sound significantly better than my on-board computer DAC to me. The amp certainly makes a much larger difference to my ears. It's not what an audiophile would consider "good", but aren't most DAC's these days actually pretty decent in terms of audible differences, not measurements? My iPod Video has pretty good sound quality compared to the 2nd gen iPod Touch, but I don't know if that's due to the DAC (Wolfson vs Cirrus) or if it's due to the amp....I should really get one of those LOD's in the near future, shouldn't I?

 

 

 

The onboard sound you have is probably very flat and accurate. I know this sounds hard to believe, but my "crappy" Realtek HD sounds better than the Fiio E10 and a lot of other DACs. Mine is even labeled as having a headphone amplifier built in(!). This is on my MSI motherboard! Bizarre.

Based on my experience, some of my headphones have benefited very little from DAC upgrades. It seems that my HD-650, DJ100 and Q701 have the most. My HD-598 doesn't seem to change a bit with anything. Not even my HD-600 does much as long as it's properly amped.

 

To me the Ipod Video sounds a bit warmer than the Ipod Touch 2G. The Ipod Video 5.5 supposedly has slightly forward upper mids and rolled off low bass.

 

The Ipod Touch 2G to my ears sounds very similar to my Magni+ODAC. Even brighter at times, which is weird.I think the Ipod Touch 2G is ruler flat, but sounds like it has sort of edgy treble.

Despite bypassing the onboard amp, they still seem to have the same exact signature when using the LOD cable. What's interesting is that even the Ipod Docks have a DAC chip built inside of them. Not sure why..

 

Sometimes I think this LOD cable = better sound is hogwash. I can't hear any distortion from using my Fuze's headphone out to amp. I'm sure it's there.

 

One thing I noticed about the ODAC is that it's treble seems way smoother than 5-6 of my full sized CD players. Not sure why, but it's hard to believe all those are that much worse..

It's not coming from my amp..my amp has no rolled off treble or anything. I highly doubt the ODAC has rolled off treble..

Woah, woah woah........wait a sec. The V-MODA Crossfade M-100 "sounds better" with the iPod Touch 2G versus the O2/ODAC? Colour me surprised, but the whole midrange is forward, not laid-back, on this setup. O_O

I still like the O2/ODAC for being transparent though, no worries there because with that I actually know what the M-100's true sound is like.

post #197 of 498
Quote:
Originally Posted by miceblue View Post

iPods tend to have a high output impedance (something like ~7 ohms)

5.5Ω (iPod Classic) and less (the latest iPod Touch was measured at 0.75Ω).
Quote:
Originally Posted by miceblue View Post

I don't know what happens when the output/source impedance ratio is less than 8)?

Poor/inexistant damping, and possibly frequency response variations if the headphones' impedance varies with certain frequencies.

Sansa Clip+ (0.5Ω) with Ultimate Ears Triple-Fi 10:



iPod Classic (5.5Ω) with Ultimate Ears Triple-Fi 10:



Hifiman HM602 (11.4Ω) with Ultimate Ears Triple-Fi 10:


Edited by skamp - 1/22/13 at 2:25am
post #198 of 498
Quote:
Originally Posted by miceblue View Post

does the DAC really make a difference in sound quality? I only have 1 dedicated DAC (ODAC) and it doesn't sound significantly better than my on-board computer DAC to me. The amp certainly makes a much larger difference to my ears.

Indeed, onboard DACs are often able to deliver fine 16 bit performance these days. The main problem is the high output impedance of the headphone out (my laptop measures at 74Ω), which can be fixed with a decent headphone amplifier such as the O2.
post #199 of 498
Thread Starter 
Quote:
Originally Posted by Satellite_6 View Post

Wow the new version looks stunning, I just missed it unfortunately. :| I am very much enjoying my boring silver one tho. 
 
Some additional stuff I wanted to say after reading the thread, not very organized: 
 
It was in fact designed as a portable amp.
 
The HD 650's sound great out of the O2. They are smooth an muscial and the O2 doesn't add anything to that obviously.
No "synergy" is necessary to get the most out of them.
Calling them inaccurate and veiled is ********. Do not claim everything is subjective and then say they are inaccurate crap. 
For that you would have to break out frequency plots and a lot worse looking ones than the HD 650's exist for sure. 
Not everyone likes their sound signature and that's fine. . . 
 
The LCD-2's are not that hard to drive so the O2 can surely dive it "to its full potential in the bass department."
 
You should not use the high gain mode with the ODAC, so 2.5X is probably a better idea than only 1X just in case. i.e. 1X would be marginal to get the HD 650's very loud.
 
Oh god it's that cable guy. No comment. 

 

Sorry to offend you, but i did say IMO i did not like the HD650, i dont like the sound signature of them, too warm for my taste.

 

Also i know it was made to be portable, but because of the size, it is more transportable.

 

And cables, yes i believe they make a difference, maybe not as big as some say, but with the Shure SE535 and my alclair reference monitors i do notice a difference between a cooper and a silver olated copper cable. Bass a little tighter but looses some body, mids gain more presence and deail, also highs are more extended. I also prefer the looks and build of my own silver cables, i use silver solder as its easier to work with too.

 

Im not saying cables are the be all and end all, but for subtle differences, i like them. Also they dont have to be super expensive.


Edited by ostewart - 1/22/13 at 2:08am
post #200 of 498
Quote:
Originally Posted by randomkid View Post


Im not saying cables are the be all and end all, but for subtle differences, i like them. Also they dont have to be super expensive.

Supposedly in double blind testing no one can hear any difference. I haven't tried this myself so all I can contribute is an anecdote:

When I was a teen I tried to solder a new jack on to the end of my cheap headphones. Knowing what I know now about soldering, there's no question that I did a very bad job. The end result was appalling sound quality. I threw them away. Even the O2 designer has mentioned that poor quality banana plugs may affect sound quality. But this is a matter of defect rather than metals and solder used. Assuming there isn't an defect then except with long cable runs, there shouldn't be any difference in the audio.
post #201 of 498
Quote:
Originally Posted by miceblue View Post

This is probably going to end up sounding like a really dumb question, but does the DAC really make a difference in sound quality? I only have 1 dedicated DAC (ODAC) and it doesn't sound significantly better than my on-board computer DAC to me. The amp certainly makes a much larger difference to my ears. It's not what an audiophile would consider "good", but aren't most DAC's these days actually pretty decent in terms of audible differences, not measurements? My iPod Video has pretty good sound quality compared to the 2nd gen iPod Touch, but I don't know if that's due to the DAC (Wolfson vs Cirrus) or if it's due to the amp....I should really get one of those LOD's in the near future, shouldn't I?

AFAIK a LOD doesn't make much difference in a good design. Perhaps a bit less crosstalk (better stereo). It should also give 2.1 V output which mean less need for high gain settings on amps, but some LODs don't.

As for onboard DACs. I've compared (with level matching but not DBT) the ODAC/O2 against a 5 year old sigmatel implementation and also a recent Realtek using my etymotics (which are kind of reference grade phones themselves). Apart from a tiny bit of noise (and I mean really tiny), I can hear no difference. I also measured the sigmatel headphone jack and it has an output impedance of 0.5 . I was quite shocked.

Now, perhaps there is in fact more distortion, but not such that I could consciously hear it but rather that would reduce the pleasure of the music. For that I would probably need to DBT to detect it. But my suspicion is that, as with modern speaker amplifiers, the DAC technology is mature and settled and hifi. So long as it's one of the cheap standard chipsets, you'll get as good as it gets. It's when manufacturers stray in to fancy stuff like Wolfson that I would expect issues; at the very least more noise. If the ODAC designer's reports are anything to go by, it's expensive to do a good implementation to realise the performance of a chipset. The Standard chipsets have already done that work.
post #202 of 498
Thread Starter 

Another thing with cables, is that i make my own, i would not spend hundreds of dollars on one, when i can make myself one for less than half the price.

 

I only use an LOD as i dont want to double amp, and also on the go i like to use an amp too.

 

My portable rig is quite a nice size IMO, IPod classic + C421 = perfect size harmony.

 

 

1000

post #203 of 498

Hey guys,i really need some help because i am shii-thing the pants out right now.i hope you technical guys can tell me some positive thoughts..

 

I did received Friday my very first O2-Odac combo.I did ordered them on September ,but then my first package has been lost,then before to JDS send me another unit i had to wait for some complaining form to USPS and then another month to the new package to arrive here.well i did learn something more about patience ,hehe.

 

So,when i received my combo i've gone to Capital city to find an adapter for the amp,but the first night i have been home with the combo i let the adapter on the 110V switch whereas my home town support 220V.Well for the first days i thought the batteries or the plug where not having a good connection because the O2 were able to work for a couple of minutes before stopping working.

 

But then,i realize my stupidest misuse:The wrong switch on the voltage input.

Now,i did call the manufacturer of the adapter and they told me that possibly the adapter would blew just after 30 minutes on the wrong switch input (well it has been all night plugged in ,and the amp turned on).

My first worries were about the adapter but now i am afraid more about the amp,because they told me too that if the output voltage in my case is wrong the amp could receive more or less for about  28 volts,which i know is very high for the amp,so i hope i did not damaged my beloved and so long awaited amp.

If this could help you,as i sad before,the amp just work for a few minutes before stopping working,due i suppose to the low charge of the batteries inside.

I hope i have been clear as English is not my native language.

Thank you very much guys

post #204 of 498
Thread Starter 
Try opening and putting some normal 9v batteries in to see if its the batteries or the amp, if it works, then the amp is fine and the batteries have no charge, if it doesn't work, then maybe the amp has a problem. Before closing, put the rechargeable batteries back in, DO NOT TRY AND RECHARGE NORMAL BATTERIES, and get the right adapter.
post #205 of 498

The ODAC-O2 combo , anyone that is running 250ohms / 600ohms Beyer DT 880 or 990? I'm also looking at the HD700.

 

Thanks


Edited by snip3r77 - 1/22/13 at 7:40am
post #206 of 498

Thank you fella,thank you very much.I have been on the electric shop near my house and they could not help me because they had not an opened multimeter,so today on may way to work i am going to the main shop where i did brought the adapter so i can see if i can change the adapter ,and more important if i can find some normal battery to check on your advise.

Tonight i let you know,going right now to Porto Alegre where work,before passing to the shop.I guess that's a very logical advise you told me.

See you all later

Antonio

post #207 of 498
Thread Starter 
Quote:
Originally Posted by snip3r77 View Post

The ODAC-O2 combo , anyone that is running 250ohms / 600ohms Beyer DT 880 or 990? I'm also looking at the HD700.

 

Thanks

 

O2 + HD700 works great, plenty of power and good sound.
post #208 of 498
Thanks for the prompt response.

My odac O2 combo is set for 1x and 2.5x.

How does the gain correlates with impedance? Am I missing anything with 6.5x?

Thanks
post #209 of 498
You're missing the ability to properly amplify low power sources, such as DAPs.
post #210 of 498
Thread Starter 
Using the ODAC too you won't be missing anything I don't think. The only problem would be if your using a weaker input like a DAP
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