Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › O2 AMP + ODAC
New Posts  All Forums:Forum Nav:

O2 AMP + ODAC - Page 51

post #751 of 3218
Quote:
Originally Posted by adydula View Post

13.69 years at once a day...

  6.84 years for twice a day.

with extension cable almost forever....

Exactly, I use my O2 everyday, and change headphones and configs quite a bit. If I want it to last the 15 years I intend then I must use a short extension cable.

I've also had the unpleasant experience of desoldering one of these and it's a pig. I damaged the circuit board and had to solder in a patch wire which can only increase noise.
post #752 of 3218

sorry for the off topic(ish), but id like to take this chance to ask a question, if i may.

 

why would you disconnect your headphones at all? iv heard that the "buzz" you get when turning amps on/off can damage your cans, is this an established fact or another controversial topic with mixed opinions all over the place? or is there some other reason? my cmoy (soon to be replaced by O2 that shipped on thursday =]) is allways plugged into my computer, and my headphones are allways connected to the cmoy. is there any reason to disconnect them?

post #753 of 3218

lorriman,

 

yes if you want a 1/4 jack u definitely want to wire that up when DIY'ing and not use the 3.5 jack at all on the board. You could wire after and mechanically file down the front of the 3.5 mm plastic jack part...but thats kind of kludgy...at best

 

Alex

post #754 of 3218
Quote:
Originally Posted by adamlr View Post

sorry for the off topic(ish), but id like to take this chance to ask a question, if i may.

 

why would you disconnect your headphones at all? iv heard that the "buzz" you get when turning amps on/off can damage your cans, is this an established fact or another controversial topic with mixed opinions all over the place? or is there some other reason? my cmoy (soon to be replaced by O2 that shipped on thursday =]) is allways plugged into my computer, and my headphones are allways connected to the cmoy. is there any reason to disconnect them?

 

People disconnect headphones all the time to be able to plug in different ones. but people also traditionally do so to avoid having  the headphones plugged in while the amp is turning on and off, as you say.  For some amps, that is a safer practice, but for others it shouldn't matter.

 

As for leaving them in when powering the amp on and off, it depends on the structure of the amp, how it's designed.  More or less, as internal power supply rails are moving from 0 to the operational value (or vice versa, on shut off), this can induce some nonzero output in some parts of the circuit.  Ultimately, this means that an unwanted junk transient signal can be generated between the output and ground, so that's what your headphones would receive this they're plugged in.  That causes the buzz you hear.  In terms of the danger to the headphones, it's the same as any other kind of sound or music you put through the amp.  The magnitude, duration, nature of this junk signal, and the headphone properties determine whether or not it is dangerous.  

 

Often if there's a signal large enough to cause a problem, you would hear an extremely loud sound out of the headphones as a result.  However, in some cases, the signal is mostly a very low frequency that you can't hear, so that could be damaging without being audible.  Some amps have some relay to disconnect the headphone output on power up / down to avoid this problem; many don't generate a large enough signal to be an issue in the first place.  If properly assembled and working, an O2 is in the latter category and doesn't make a large enough signal to damage any IEMs or headphones. Actually, if it does make a loud sound, that's an indication that something is wrong with the power management circuit.

 

No reason you can't leave it in all the time.  For that matter, power draw is so low that there's not even really a reason to turn it off, either.

post #755 of 3218
The loudest thump I usually hear is when the batteries are discharged and the O2 shuts itself off. While I don't like popping and buzzing, nothing the O2 does scares me since it is all way too quiet to be bad.
post #756 of 3218
Quote:
Originally Posted by mikeaj View Post

 

People disconnect headphones all the time to be able to plug in different ones. but people also traditionally do so to avoid having  the headphones plugged in while the amp is turning on and off, as you say.  For some amps, that is a safer practice, but for others it shouldn't matter.

 

As for leaving them in when powering the amp on and off, it depends on the structure of the amp, how it's designed.  More or less, as internal power supply rails are moving from 0 to the operational value (or vice versa, on shut off), this can induce some nonzero output in some parts of the circuit.  Ultimately, this means that an unwanted junk transient signal can be generated between the output and ground, so that's what your headphones would receive this they're plugged in.  That causes the buzz you hear.  In terms of the danger to the headphones, it's the same as any other kind of sound or music you put through the amp.  The magnitude, duration, nature of this junk signal, and the headphone properties determine whether or not it is dangerous.  

 

Often if there's a signal large enough to cause a problem, you would hear an extremely loud sound out of the headphones as a result.  However, in some cases, the signal is mostly a very low frequency that you can't hear, so that could be damaging without being audible.  Some amps have some relay to disconnect the headphone output on power up / down to avoid this problem; many don't generate a large enough signal to be an issue in the first place.  If properly assembled and working, an O2 is in the latter category and doesn't make a large enough signal to damage any IEMs or headphones. Actually, if it does make a loud sound, that's an indication that something is wrong with the power management circuit.

 

No reason you can't leave it in all the time.  For that matter, power draw is so low that there's not even really a reason to turn it off, either.


thanks a bunch =]

 

so if i understand correctly, while going from "off" mode to "on" mode (or the other way around), some sort of grey area is crossed, which may release unwanted electrical/audio output that can only damage your headphones if they're loud enough?

 

and you say that a properly assembled O2 (like say, jds) can be left plugged in, and headphones in turn, can be left plugged into the O2, at all times, including turning off/on, and everything should be fine, so long as i keep things on the sensible side of the volume control. right?

 

i plan on leaving my O2 plugged in to the wall, and disconnect the batteries. im guessing this wont make any difference, since you say it "doesn't make a large enough signal", and that "power draw is so low"?

 

cheers!

post #757 of 3218

Is there suppose to be a sold of something rolling around inside the O2? it sounds like a ball on a track or something like that.

 

Also I thought I was getting a power adapter for this now I'm kinda out of luck

post #758 of 3218

What kind of power adapter can I use, I'm from USA and I would look on JDSLabs website but I can't get to it :(

post #759 of 3218
Quote:
Originally Posted by kskwerl View Post

What kind of power adapter can I use, I'm from USA and I would look on JDSLabs website but I can't get to it :(

 

There is a list of adapters recommended by the designer near the bottom of the instruction page which comes with the O2. I'd post a link to a PDF version ... but JDS' web server isn't responding at the moment. The list is also available on the designer's blog ... but I can't post a link to it here. Trying a Google search for 'objective2 power supply'.

 

Quote:
Originally Posted by kskwerl View Post

Is there suppose to be a sold of something rolling around inside the O2? it sounds like a ball on a track or something like that.

 

Also I thought I was getting a power adapter for this now I'm kinda out of luck

 

No, there isn't supposed to be anything loose. The power adapter isn't included in JDS Labs' base price for the O2 (or ODAC+O2 combo).


Edited by HamilcarBarca - 2/2/13 at 6:19pm
post #760 of 3218
Quote:
Originally Posted by HamilcarBarca View Post

 

There is a list of adapters recommended by the designer near the bottom of the instruction page which comes with the O2. I'd post a link to a PDF version ... but JDS' web server isn't responding at the moment. The list is also available on the designer's blog ... but I can't post a link to it here. Trying a Google search for 'objective2 power supply'.

 

 

No, there isn't supposed to be anything loose. The power adapter isn't included in JDS Labs' base price for the O2 (or ODAC+O2 combo).

ok I just ordered the power adapter recommend on the list that came with the O2, I'm gonna open it up now and see wtf this noise is. 

post #761 of 3218

Ok looks like it was just the faceplate that was jiggling around a little cause it wasn't tight enough.

 

I got some velco circles and they are freaking awesome fit for attaching the ODAC to the O2. Take a look

 


Edited by kskwerl - 2/2/13 at 7:21pm
post #762 of 3218

Perfect, I would suggest rotating the odac 90 degrees and possibly flipping it upside down too, to get the usb cable out of your way.

post #763 of 3218
Quote:
Originally Posted by chrislangley4253 View Post

Perfect, I would suggest rotating the odac 90 degrees and possibly flipping it upside down too, to get the usb cable out of your way.

oh wow I never thought of that, the flipping it upside down thing. thanks for the tip

post #764 of 3218

Can anyone comment on the O2 and 600ohm beyers?

post #765 of 3218
Quote:
Originally Posted by kskwerl View Post

Can anyone comment on the O2 and 600ohm beyers?

 

I'm sure searching this thread will give you the answer you want. This question has been asked and answered numerous times here.

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphone Amps (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › O2 AMP + ODAC