[anthk]

  I also own an O2 + ODAC combo and these are some of my observations.
 
I can't verify anything. I am not really sure if the audio that I am getting from the line-in is actually from the ODAC or not. However, there is in fact audio that is coming from the line-in once the O2 amp is turned off. Whatever indication this is I do not know. Even when the power is on the line-in still acts as an output for what I believe to be the ODAC. The volume knob does not affect the actual output of the line-in. I think that while the combo is still connected to the computer via usb, the line-in will continue to act as an output for the ODAC. 
 
I suppose this would be useful if you had another amp and wanted to use the ODAC as the D/A converter or you simply wanted to test different D/A converters. As far as speakers go, you will need an amp for them and I do not think directly connecting them to the ODAC which has no power output is ideal. Of course, this depends on what type of speakers you run too. 
 
There seems to be a lot of flexibility with the combo as far as I know and you can personally try out what you think works the best for you since you already have the unit with you. Good luck.

My only concern is would any of these connections overload the circuit/headphone/speaker and cause damages?

 

[Poladise]

Thanks for the info agdr

 

[agdr]

Here is some potential good news for folks with the low battery problem.   The O2 booster board is a T shape, but the PC board fabrication house does 5cm by 10cm of area whether it is used or not.  Looks like I can fit a couple of those O2 latch circuit boards in the unused space around the booster board. 
 
The way it would work is just unplug the U2 chip on the O2 board (the NJM2903D) and plug in this little board instead.  What looks like a DIP socket on the little boards is two more sets of connection pins, like on the booster board, that plug into the O2's U2 socket.  Plus one wire has to go from the latch board and solder on to the end of a resistor on the O2 PCB.  Just like that no more low-battery "motorboating".   The O2 stays off until the O2 power switch is turned off then on to reset the latch circuit.  This board could also be used with the O2 booster board, but most likely the booster board solves the problem all by itself since the headphone relay has an 5 second turn-on delay.  The relay (and headphones) would just stay off while the O2's PM circuit is oscillating.
 
All DIY (and surface mount parts and soldering).  The LM2903 surface mount comparator chip on the latch PC board just replaces the NJM2903 that was in the O2's U2 socket (exact same specifications for both), plus adds the extra O2 power management latch circuit.
 
I don't want to sidetrack this thread with my DIY stuff, so check in the DIY forum here in the booster board thread for follow-ups.  It will probably be a few weeks before I do a board run.  All at-cost of course (non-commerical).  I'll post the Gerbers again so anyone who wants to can fabricate boards too.
 

 

[locksbury]

Hi
 
I had success yesterday listening to my O2+ODAC combo on my Windows box and again very please with the sound.

 
However, when I tried it on my Linux laptop (fresh Slackware 14.1 install), there was no sound...

 
I've done the usual searches on this forum and elsewhere, but not found any useful info and so I thought I'd pick your brains here.
 
So far:
 
- ODAC works with Mac and Windows, so the hardware is good.
- Confirmed the laptop is outputting sound from it's own speakers.
- When plugged in, the ODAC is shown as detected in ALSAmixer.
- I checked I'd unmuted the channel and turn the volume up to 100%.
 
Any ideas or suggestions from other who've had this issue?

 

[pearljam50000]

Can anyone compare to Meridian Explorer?

 

[James neutron]

What would you like to know? And in what context (e.g. which headphones will you use) ?

 

[pearljam50000]

SQ wise only.
I'm not sure about the headphones as of yet.

 

[James neutron]

I think the choice between the two is largely dependent on the headphones you will be using.  The sound quality is very similar between the two and I think it's ultimately up to personal taste/preference in choosing one over the other.
The o2-Odac has the ability to drive better more demanding headphones, while the Explorer is more limited and won't reach nearly the same loudness with less sensitive headphones.
Meridian also had issues with the first few batches due to the high output impedance, which affected it's performance with low impedance, high sensitivity, headphones like IEMs.
But from what I understand that issue has been addressed and the output impedance was lowered to 5 ohm (compared to the original 50 ohm).
I had the first version, but didn't notice any impedance related issues with it driving either my high impedance AKGs or the portable Martin Logan, rated at a low 26 ohm.
Ultimately the Meridian will be more limited in terms of output power. So if you plan to buy a headphone with a relatively low sensitivity and high impedance you might prefer a bit more headroom. Otherwise it should be fine.

 

[jring]

No idea why Slackware doesn't work (I assume you know http://linuxcritic.wordpress.com/2009/08/18/how-to-set-up-sound-in-slackware/) but I can confirm that ODAC works fine with linux in general (tried various ubuntu and debian systems).
 
Joachim

 

[locksbury]

  No idea why Slackware doesn't work (I assume you know http://linuxcritic.wordpress.com/2009/08/18/how-to-set-up-sound-in-slackware/) but I can confirm that ODAC works fine with linux in general (tried various ubuntu and debian systems).
 
Joachim

Hi Joachim
 
As per sods law I managed to get some sound a bit later; well at least playing through Xmms.

 
I'll have to look at that guide you linked and similar ones later to get all sound via the ODAC.
 
Locksbury

 

[CADCAM]

Is there a way to run an ODAC from the optical or digital coax output of a disc player? Or is it strickly USB?
I have a O2 (and love it) and would like to bypass the internal DAC on my cd player and use the ODAC as an external DAC.

 

[BenF]

  Is there a way to run an ODAC from the optical or digital coax output of a disc player? Or is it strickly USB?
I have a O2 (and love it) and would like to bypass the internal DAC on my cd player and use the ODAC as an external DAC.

ODAC is strictly USB

 

[CADCAM]

I purchased a DAC that has optical, digital coax and BNC inputs. Can I run all three of my optical drives to it? All my drives have optical out as well as digital coax. I was going to purchase a BNC to RCA (75 ohm) cable for the third drive. Sorry if this question is off topic. 

 

[locksbury]

  Hi Joachim
 
As per sods law I managed to get some sound a bit later; well at least playing through Xmms.

 
I'll have to look at that guide you linked and similar ones later to get all sound via the ODAC.
 
Locksbury

 

  No idea why Slackware doesn't work (I assume you know http://linuxcritic.wordpress.com/2009/08/18/how-to-set-up-sound-in-slackware/) but I can confirm that ODAC works fine with linux in general (tried various ubuntu and debian systems).
 
Joachim

 
I took a look at that guide and a few others, but still can't get the ODAC to be set as the main sound card in Linux. Will have to do some more digging. Oh well, at least I can use xmms to listen to my music collection.

 

[jring]

http://alexpb.com/notes/articles/2009/04/20/howto-change-default-sound-card-slackware-linux/