[syphen606]

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Pretty good speed. Have you done DIY before?

I think I can make em faster now. The 3 hours was from all parts bagged and packed from Mouser/JDSLabs & Allied Electronics/Beer Store, to a fully assembled product tested and function checked.  I have parts for a 2nd one that I'm making for a friend later this week.
Haven't done any DIY audio stuff, no. I did go to school for electrical engineering back in the day and did a short stint at an electronics company in the engineering department troubleshooting boards and assembling prototypes.   I guess the experience helped.
 
Just giving it a quick listen now. Haven't pulled out my HD650's but tried a set of ATH-M50's and HD558's on it.  This amp is CLEAR.  REALLY clear and detailed. It made my HD558's really bright. Much brighter and detailed then I've heard them.  It makes the ATH-M50's sound fantastic. Really gives me a new appreciation for these headphones. Clears them right up and gives me a sound that I like. Super detailed sounding with enough bump to be fun.   Noticed minor minor channel imbalance with the HD558's with the pot at the near-off position, but it cleans up and goes away with virtually 1/32" of a turn on the dial. Nothing to be worried about.  
 
My C421 is in my car and I'm not feeling like getting it at this moment, but compared to the E10 and CmoyBB I have on my desk in front of me, this amp is very very detailed.  I played a couple songs that I hadn't heard a bit of noise in the background. I thought maybe I had assembled something bad and was getting distortion. Ran the amp through several slow frequency sweeps from 20hz-16khz (I can't hear above that so didn't bother pushing it) and at several volumes without any distortion.  Gave it some more listening time before realizing I was just hearing garbage in the background of a bad recording hah!   Love the detail this amp has for sure.

 

[Crazy*Carl]

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I think I can make em faster now. The 3 hours was from all parts bagged and packed from Mouser/JDSLabs & Allied Electronics/Beer Store, to a fully assembled product tested and function checked. 

Did you get all the parts in a kit, or did you have to go on a wild goose chase to obtain everything.  I am open to the idea of trying a build, but the task of finding all the parts seems daunting.

 

[syphen606]

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Did you get all the parts in a kit, or did you have to go on a wild goose chase to obtain everything.  I am open to the idea of trying a build, but the task of finding all the parts seems daunting.

"Wild Goose Chase" was my route. Its not that bad to be honest.     I got the enclosure from Allied Electronics. PCB & Faceplate from JDSlabs, and all the internals and ac adapter came from from Mouser.  There is an .XLS bill of materials on the internet that you can upload onto Mouser once you have an account and it will fill your shopping cart based on the xls file. It was actually all quite easy and only took about 2 weeks to get all the parts from the time I decided to make an O2.
 
 
I just added a set of rubber feet and changed the volume knob to an kilo ml-50-6 knob. The same one that the JDSLabs finished units ship with I think. It was on a CmoyBB I had kicking around here and it looks sharp so on it went!! 
 

 

 

[Anaxilus]

^  Not sure about your E10 but the one I sampled was bass light.  I heard they were or did a revision to it FYI.  The O2 is definitely the strongest part of your chain.  If you ever want to upgrade I'd look at the DAC first then headphones.
 
 

 

[scoopbb]

i just received the pair of hd650s i ordered and man it sounds amazing with the o2. i am using an e10 but i wanna upgrade to a better dac. debating the ms or ms+. any ideas/.

 

[syphen606]

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^  Not sure about your E10 but the one I sampled was bass light.  I heard they were or did a revision to it FYI.  The O2 is definitely the strongest part of your chain.  If you ever want to upgrade I'd look at the DAC first then headphones.
 
 

The E10 amp component has weak bass on its own, yes.  I have HD650's as well but couldn't be bothered to pull them out of the case last night as I was only testing functionality of the amp (make sure I didn't mess up the assembly) and the 558's and M50's were on the desk when I got home.  
 
 


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i just received the pair of hd650s i ordered and man it sounds amazing with the o2. i am using an e10 but i wanna upgrade to a better dac. debating the ms or ms+. any ideas/.

I'd wait for the ODAC. The design is expected to be released this spring and by the looks of things, will be offered as a retro-fit for existing O2's.  It looks like you will lose the batteries and "portability" of the O2 but gain what no doubt will be a good DAC. It will require a new back plate also:
 

 

 

[Twinster]

*** For all O2 owners ***
I have extra aluminium knobs so if you want to upgrade from the basic plastic knob here are some option for you.
 
 

[size=small](3x) AlcoKnobs model kn700b Knurled in Black Aluminum.[/size]

 
I also have one silver Kilo that I bought from JDS Lab
 

 
 
I'm asking $10 each including shipping in CONUS/Canada only. Please send me a PM if interested. Thanks!

 

[sphinxvc]

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I sometimes hear a slight crackling in the background during loud passages.  It's very subtle.  Is this the same thing you clippers are hearing?

 
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Nope.  No crackling.  Dead quiet background.
 
I'm not convinced that what I heard was clipping.  I called it distortion.  But what ever it was it sounded like when you turned a radio up too loud, past the point of maximum sound quality.  I'll check again later tonight and see if it's still there.

Ok, I finally figured out what the crackling was, and I was correct, it was clipping.  The good news is it wasn't from the O2.  The bad news, it was from my new and rather expensive DAC.  

 

[sonitus mirus]

Was your Antelope causing the clipping?  Hope not. 
 
I thought I was hearing things on the second day with my O2.  When I read about your experience with crackling sound, it matched the description I was hearing.  The sound was like the "popping" heard between songs on a vinyl record, and at times it sounded like feint static from a radio tuner.  After a bit of troubleshooting, it appeared to be the quality of the recording.  The song I was listening to was actually dubbing sounds from old records, and I was picking this up with the clarity of the O2.  A few days later I thought I heard the issue again, but upon further examination it turned up being the sound created from the scraping of a guiro in a latin song that was playing.
 
This amp is very revealing, and I didn't think that amps were supposed have that type of impact on the sound.  I don't know, it just seems like every odd beep, whistle, or bump causes me to freak a bit until I determine that it is not a problem with the amp.  I listen to a lot of new stuff every day, so I am usually hearing songs for the first time.  I went back and listened to a playlist of my older favorites, and the experience with the O2 was much more relaxing. Still, this amp is definitely a bit different than my previous amp it replaced. (HeadRoom Micro Amp)

 

[upstateguy]

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Ok, I finally figured out what the crackling was, and I was correct, it was clipping.  The good news is it wasn't from the O2.  The bad news, it was from my new and rather expensive DAC.  

 
How is  your DAC clipping?
 
 

 

[sphinxvc]

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How is your DAC clipping?

Antelope has a application to control the DAC and see a "peak meter" which has a clipping indicator.  It lights up at the exact times I hear the crackling, so I'm assuming it's clipping.  The only unknown in all of this is whether it's just inherent in the recording, and would clip on any normal DAC, or if there's something wrong with the Zodiac.  Edit: I should probably dial back the volume pot and see if there's any crackling then.  Anyway, sorry to take this thread off topic, just wanted to clear up that it wasn't the O2.  

 

[upstateguy]

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Antelope has a application to control the DAC and see a "peak meter" which has a clipping indicator.  It lights up at the exact times I hear the crackling, so I'm assuming it's clipping.  The only unknown in all of this is whether it's just inherent in the recording, and would clip on any normal DAC, or if there's something wrong with the Zodiac.  Edit: I should probably dial back the volume pot and see if there's any crackling then.  Anyway, sorry to take this thread off topic, just wanted to clear up that it wasn't the O2.  

Just to be clear, you mean dial back the volume of the DAC, right?  Does this happen on low gain?  Does it happen with all your recordings?  Does changing the volume on the DAC effect the sound quality in any way?  What headphones?  Any other pertinent information?

 

[sphinxvc]

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Just to be clear, you mean dial back the volume of the DAC, right? Yeah.

Does this happen on low gain? Yes.

Does it happen with all your recordings?  No, just some.  Albums with good dynamic range don't have the problem.

Does changing the volume on the DAC effect the sound quality in any way?  It shouldn't, since the Zodiac doesn't have digital volume control, I'm assuming I wouldn't be losing bits/quality.  

What headphones?  LCD-2s.

Any other pertinent information?  Afraid not, trying to understand it myself.

 
 

 

[mikeaj]

I am not at all familiar with this DAC, but to me this description almost certainly seems like a signal clipping detector. It's just saying that the input bits themselves (from the music file) go to 0 dBFS.  Or maybe 0 dBFS for multiple samples, or something like that?  It depends on how it's set up to report clipping.  So that's not the DAC clipping but the music file itself containing clipping.  Blame the guy who mastered it.  The whole peak meter thing is just reading the digital values being sent through to the D/A chain, including whatever might be approaching clipping levels.  Open up the files in something like Audacity and look for clipping there and see if it's happening where the signal goes to 0 dBFS.
 
It would take an incompetent design to have the DAC itself be causing the clipping.  Or a "design decision" according to some.  

  That's a totally off-topic potshot though, so I'll let it go now.  

 

[sphinxvc]

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I am not at all familiar with this DAC, but to me this description almost certainly seems like a signal clipping detector. It's just saying that the input bits themselves (from the music file) go to 0 dBFS.  Or maybe 0 dBFS for multiple samples, or something like that?  It depends on how it's set up to report clipping.  So that's not the DAC clipping but the music file itself containing clipping.  Blame the guy who mastered it.  The whole peak meter thing is just reading the digital values being sent through to the D/A chain, including whatever might be approaching clipping levels.  Open up the files in something like Audacity and look for clipping there and see if it's happening where the signal goes to 0 dBFS.
 
It would take an incompetent design to have the DAC itself be causing the clipping.  Or a "design decision" according to some.  

  That's a totally off-topic potshot though, so I'll let it go now.  

Incompetent, but I wouldn't put it past anyone.  

  I vaguely remember hearing something similar on my NFB-3 DAC, so I am leaning toward it being inherent in the recording.  Thanks for the input.