Review: JDS Labs O2 (Black edition) + O2/ODAC discussion
Jan 2, 2013 at 4:28 PM Post #31 of 543
Quote:
Actually it's 18v... And yes the HD650 is crap IMO, outdated, veiled and too warm. Complete opposite to what I like, I enjoy a accurate sound.

This is my opinion, I didn't even really like the HD700, I also found it a little warm, but more detailed.

Hey I'm in with you on that. Every time I've tried the HD650, whether it be SS amps, Schiit Amps, Woo Audio amps, Bottlehead Crack amp, I have not liked its sound. To me it remains a mystery as to why so many people like it. For the ~$300 street price nowadays it sounds pretty good though, although I prefer the sound signature of an AKG K 701.
 
That being said, the O2 drives the K 701 quite well from my experience. It definitely sounds more detailed and the soundstage is to its maximum potential with it versus Woo Audio and Schiit products. When I brought the O2/ODAC to the last local Head-Fi meet I went to, people were mighty impressed with how the O2 sounded. People said it could drive an LCD-2, but not to its full potential in the bass department.
 
Jan 3, 2013 at 3:11 AM Post #32 of 543
Yay, thread open again, now lets not let it go down the same road again, discussions regarding the O2 amp, and not perceived neutrality please
 
Jan 3, 2013 at 3:16 AM Post #33 of 543
Quote:
Yay, thread open again, now lets not let it go down the same road again, discussions regarding the O2 amp, and not perceived neutrality please

THANK GOD. I don't feel like editing my  post on O2 + ODAC so I'm going to leave it there. Anyways, I thought it was a great review, I would lend my ODAC to you. But your just too far away for my comfort.
frown.gif

 
Jan 3, 2013 at 3:41 AM Post #34 of 543
JDS said they would send me one either this month or next month, or Epiphany Acoustics as they have one wkth RCA outputs, and may send me one.

Thanks
 
Jan 3, 2013 at 3:54 AM Post #35 of 543
Quote:
JDS said they would send me one either this month or next month, or Epiphany Acoustics as they have one wkth RCA outputs, and may send me one.

Thanks

For free?
eek.gif

 
Jan 3, 2013 at 4:08 AM Post #36 of 543
Great review Random. So if I was looking for a upgrade to my little e11 I was thinking the new e07k, O2, or C421 black... I do like warmer sounding so would I be better off with the other two vs the newer O2? They'll be paired with my iPhone 5, Old School iPod, or MacBook Pro source. Cans D5000's, JVC s500 (maybe), and DT990/250 Pro's
 
Jan 3, 2013 at 4:18 AM Post #37 of 543
C421 is warmer, wait until February and keep an eye on JDS, don't jump on the C421 just yet.
The O2 is transparent, so if your headphones are warm it won't make them bright they will stay warm.

Im waiting for the Fiio E12 which I hope to be reviewing when it's officially released.

Wolf: I'm finally making it as a reviewer, so its a sample, no commercial value. But yes it's free.
 
Jan 3, 2013 at 11:14 AM Post #39 of 543
I would hope that all the O2 fans and people that are looking to buy or DIY one would really read the designers blog, not for the diatribe but for the technical design points and what things seem to really affect an amps being transparent etc....
 
The guy has done a wonderful job of exploring many of the specs that seem to possibly have an impact on the source signal etc....here is the list of audio specs that he identified as the point of diminishing returns:
 
  1. Output impedance less than 2 ohms
  2. Input impedance >= 10K
  3. Frequency response +/- 0.25 dB 20 hz – 20 Khz 400 mV 16-600 Ohms
  4. Phase response less than +/- 2 degrees error 100 hz - 20 Khz 16-600 Ohms
  5. Absolute phase: Preserved
  6. Slew Rate greater than 3 V/uS using 10 Khz square wave near full output 600 Ohms
  7. Distortion under 0.01% 20hz – 20 Khz into 16 – 600 ohms from 10 mV – 400 mV RMS
  8. Channel separation better than -40 dB @ 16 ohms and –60 dB @ 150 ohms 400 mV RMS
  9. Channel balance error less than 1 dB at any setting down to –45 dB below max volume
  10. Noise under –105 dBv (103 dBu) unweighted (5.6 uV or -97 dBr referenced to 400 mV)
  11. DC offset under 5 mV typical, and ideally, under 20 mV worst case
  12. 100% stable with any realistic reactive load from 16 – 600 ohms
  13. Transient ringing and overshoot tightly controlled with all realistic headphone loads and 0.01 uF
  14. 166 mA per channel, both channels driven, peak current capability at < 1% THD
  15. 6.25 volts RMS on AC power at < 1% THD into 150 ohms
  16. 4.5 volts RMS on DC power (nominal battery voltage) at < 1% THD into 150 ohms

Take some time to read why "he" thinks these are the minimum req's and also know that the O2 delivers in these areas.....
 
Alex
 
Jan 3, 2013 at 11:31 AM Post #40 of 543
Quote:
I would hope that all the O2 fans and people that are looking to buy or DIY one would really read the designers blog, not for the diatribe but for the technical design points and what things seem to really affect an amps being transparent etc....
 
 
 
>>>>>>>>>>>>>>>>>SNIP<<<<<<<<<<<<<<<<<<<<
 
 
The guy has done a wonderful job of exploring many of the specs that seem to possibly have an impact on the source signal etc....here is the list of audio specs that he identified as the point of diminishing returns:
 
Alex

 
 
Hey Alex,
 
I'm guessing you are referring to ..WavMan?
 
Jan 3, 2013 at 2:03 PM Post #41 of 543
Hi Heat...
 
yup thats a good guess!
 
Lots of great stuff lurking on that blog...each time I read the techie stuff I learn something neat about this little gem of an amp...
 
Alex
 
 
Jan 3, 2013 at 2:56 PM Post #42 of 543
Quote:
C421 is warmer, wait until February and keep an eye on JDS, don't jump on the C421 just yet.
The O2 is transparent, so if your headphones are warm it won't make them bright they will stay warm.

Im waiting for the Fiio E12 which I hope to be reviewing when it's officially released.

Wolf: I'm finally making it as a reviewer, so its a sample, no commercial value. But yes it's free.

Wait, wait till Febuary for? Also, lucky!
 
Jan 3, 2013 at 3:31 PM Post #43 of 543
Jan 3, 2013 at 3:43 PM Post #44 of 543

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