[JakeJack_2008]

   
As long as the amp is powered down quickly, headphones will incur no damage.
 
Allowing the cyclic, low battery operation to continue for extended durations may overheat some drivers.  Note that heat damages drivers. Brief transients from O2 are safe, just as playing excessively loud and/or clipped music for a short time is also safe (extended clipped playback produces heat --> heat kills drivers).

 
Hi,
 
 
I am not experiencing any  popping sound when the 02 gets low battery.
Simply, at a certain point the batteries are 'dead' and the O2 is absolutely quiet. - No popping sound, hiss, buzz etc. et all. 
Is this normal? 

   Ha, ha, ...
 
This is exactly as if I turned the O2 off.
 
P.S.
I am extremely happy with the JDS Labs ODAC and O2 (as two separate units).

 

[jseaber]

   
Hi,
 
 
I am not experiencing any  popping sound when the 02 gets low battery.
Simply, at a certain point the batteries are 'dead' and the O2 is absolutely quiet. - No popping sound, hiss, buzz etc. et all. 
Is this normal? 

   Ha, ha, ...
 
This is exactly as if I turned the O2 off.
 
P.S.
I am extremely happy with the JDS Labs ODAC and O2 (as two separate units).

 
Also normal! The power management circuit in O2 is impacted by battery type/age, and capacitor tolerances. So, the circuit either shuts down the amp completely or slowly toggles power on and off.

 

[Mkilci]

Anyone has the Bravo Audion Ocean and O2 to compare? 

 

[Sam21]

Sorry folks, I have a question:
 
How do I make the JDS Labs O2 work without batteries and only with the AC adapter ? I took the batteries out some time ago but the unit wouldn't turn on without the batteries !

 

[adamlr]

  Sorry folks, I have a question:
 
How do I make the JDS Labs O2 work without batteries and only with the AC adapter ? I took the batteries out some time ago but the unit wouldn't turn on without the batteries !

i imagine youd need to solder the batter thingy out, and solder a cable or something to "connect the dots" as it were. im sure youll find all you need on the jds labs website. and if you email them theyll help you out for sure - they were very nice when i emailed them a while back..

 

[Sam21]

I took out the batteries, it still doesn't work, jseaber said in another thread that it must work if you just take out the batteries...maybe it is a power supply problem ? that is what jseaber said.

 

[adamlr]

  I took out the batteries, it still doesn't work, jseaber said in another thread that it must work if you just take out the batteries...maybe it is a power supply problem ? that is what jseaber said.

well he kinda knows what hes talking about doesnt he ;p only one way of finding out...

 

[Sam21]

seriously ? it doesn't power up with batteries removed ? I tried it and it didnt power up ...something wrong with my AC adapter ?

 

[adamlr]

if thats what john seaber says, then yea, id go get another adapter... hes the guy that makes these things after all.. be sure to take the old one with you so you get the same size plug. any ac-ac adapter outputting 14-20V will do (as written on the chassis). mine is 1A but if memory serves 500mA will do also... check out the site for exact requirements. 
 
just to get this straight, you emailed jds labs, and the response was that the adapter was bad and needed replacing?
if i were you, id put the batteries back in, and leave the amp on for a while, so as to empty the batteries, then plug in the adapter and see if they charge. if they dont - you need another adapter. if they do charge up, and you take the batteries out, plug the adapter in - and the amp doesnt work (like you were told it should), well, i find that alittle strange, but i am by no means an authority, i know next to nothing about electronics.

 

[Sam21]

thanks, I will use a multi-meter to see if the adapter is working or not.

 

[Ritwik]

Hi, I justed ordered O2+ODAC Combo! and I am a novice in amplifier section. I will run my Grado SR325e using this. I know Grado is easy to drive, but still I bought it to get better performance!
 
Now please tell whether my following assumptions are correct or not:
1. I need to run my Grado in low gain(i.e. NOT pressing the right pushbutton)  [Mine is not custom O2+ODAC]
2. If I increase volume, the gain will start to increase.
    So,
          Lowest gain = Low gain mode + volume at the lowest level
          Highest gain = High gain mode + volume at the highest level
 
3. It runs on AC Power. Then why the heck people are talking about batteries? Sorry for being so novice! 
   Is it the case that in the box, the ac power charges batteries and they do have a lifetime. After that they need to be changed.
 
 
WHY ARE DEVICES NOT AS SIMPLE AS IPHONES ?

 

[canDigger]

Hi, I justed ordered O2+ODAC Combo! and I am a novice in amplifier section. I will run my Grado SR325e using this. I know Grado is easy to drive, but still I bought it to get better performance!

Now please tell whether my following assumptions are correct or not:
1. I need to run my Grado in low gain(i.e. NOT pressing the right pushbutton)  [Mine is not custom O2+ODAC]
2. If I increase volume, the gain will start to increase.
    So,
          Lowest gain = Low gain mode + volume at the lowest level
          Highest gain = High gain mode + volume at the highest level

3. It runs on AC Power. Then why the heck people are talking about batteries? Sorry for being so novice! 
   Is it the case that in the box, the ac power charges batteries and they do have a lifetime. After that they need to be changed.


WHY ARE DEVICES NOT AS SIMPLE AS IPHONES ?

http://nwavguy.blogspot.in/2011/09/all-about-gain.html?m=1
Please read the blog and self educate yourself.

 

[henkie196]

• Try your Grados on both gains and listen which sounds best to you. High gain will give you a louder sound than the low gain at the same volume setting. Low gain should typically have less noise, so would be more suitable for sensitive in-ears and/or headphones. I typically have everything on low gain, but I tend to listen at low volumes only, so YMMV.
• See above, with low gain you'll be able to get a softer lowest and highest volume, with high gain you'll be able to get a louder lowest and highest volume.
• It has an adapter that turns AC power into DC power (and a lower voltage). Internally it will be running on DC (hence the batteries). Your phone does the same (and when you are charging your phone, it charges on 5V DC power, regardless what you plug it in to).

 

[Ritwik]

Thanks man!
 
I want to know the probable cases where, the chances are that my Grado can be damaged.
 
Apart from that, it's an AC/AC adapter. So who is actually converting from AC to DC?

 

[henkie196]

Hmm, you're right, it is an AC/AC adapter. You can read some more details here (probably more than you'd ever need to know). There must be some AC/DC converter somewhere in the O2. The output to the headphones should definitely be DC.
 
It mentions on the JDS labs site that their O2 + ODAC combo is without batteries, but the O2 alone does come with 2x 9V batteries.
 
/edit
I'm guessing from the designs on nwavguy's website, that in the JDS O2+ODAC combo, the ODAC PCB takes the place of the batteries, as they appear to use the same case for both the O2 and the O2+ODAC.