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O2 AMP + ODAC - Page 154

post #2296 of 5399
Quote:
Originally Posted by SilverEars View Post
 

You sound like you know a bit about digital volume levels.  :p  Can you explain how it ties into percentage of the software volume levels on the computer?  

 

Well, if you're changing the volume using the software volume slider to say 30%, all sample values are multiplied by 0.3. If you do this to to 16 bit data this means you loose between one and two bits of resolution. If the 16 bit data was scaled to 24 bit before, you still loose 1 to 2 bit of the 24 bit data word, but they're the ones which were added when scaling to 24 bit and therefore don't contain any relevant information.

 

Joachim

post #2297 of 5399
Quote:
Originally Posted by Zorrofox View Post


Are you seriously saying that all that ^up there^ boils down to using a different plug?

 

Indeed agdr has shown that the 12V 200mA wall wart which tends to be used for O2 can be inadequate in a worst case scenario and a 400mA or even 1000mA rated wall wart might be beneficial in these scenarios (this was btw. also stated by the designer on his pages). My O2 came with a 15V 400mA wall wart by default and has so far been fine with that.

 

You can just get another wall wart. Just look that it has the correct plug and have 13.5 - 20 Volt and it MUST be of the AC type - which is kinda uncommon. More than 15 or 16 Volts wastes a lot of energy and makes the power regulators get quite warm.

 

Joachim


Edited by jring - 3/28/14 at 4:44am
post #2298 of 5399
Quote:
Originally Posted by jring View Post
 

 

Indeed agdr has shown that the 12V 200mA wall wart which tends to be used for O2 can be inadequate in a worst case scenario and a 400mA or even 1000mA rated wall wart might be beneficial in these scenarios (this was btw. also stated by the designer on his pages). My O2 came with a 400mA wall wart bye default and has so far been fine with that.

 

Joachim

What headphones are you using with it?

post #2299 of 5399
Quote:
Originally Posted by jring View Post

Indeed agdr has shown that the 12V 200mA wall wart which tends to be used for O2 can be inadequate in a worst case scenario and a 400mA or even 1000mA rated wall wart might be beneficial in these scenarios (this was btw. also stated by the designer on his pages). My O2 came with a 400mA wall wart bye default and has so far been fine with that.

Joachim

Is this dependent on the mains voltage? I have 240V here.
post #2300 of 5399
Quote:
Originally Posted by Zorrofox View Post


Is this dependent on the mains voltage? I have 240V here.

you only need a mains adapter, which converts whatever you have into 15-20V AC. In this case, just buy an adapter from a local store that has that function and you'll be good to go.

 

They more or less look like this, but some have interchangeable plugs at the end:

 

 

 

I can only imagine what 240 would do to a poor O2

post #2301 of 5399
Quote:
Originally Posted by JacobLee89 View Post

you only need a mains adapter, which converts whatever you have into 15-20V AC. In this case, just buy an adapter from a local store that has that function and you'll be good to go.

They more or less look like this, but some have interchangeable plugs at the end:





I can only imagine what 240 would do to a poor O2

Thanks mate. I actually know that and one is being supplied by the manufacturer of my O2 but "jring" appears to state a couple of posts previously that it might be beneficial to get a more powerful one for the O2 when it is paired with the Q701's. I'm just asking if that advice applies irrespective of what the actual mains voltage is.
post #2302 of 5399
Quote:
Originally Posted by Xenophon View Post
 

What headphones are you using with it?

 

AKG K240 Sextett, K141 Monitor,  Beyer DT990  -  I also jury-rigged it to a Stax Energizer driving my SR-5 and Lambda Pro and it didin't sound bad at all. Common knowledge says those stax energizers want a few watts at least but for my listening levels I haven't heard a difference to using a power amp.

 

Joachim


Edited by jring - 3/28/14 at 6:27am
post #2303 of 5399
Quote:
Originally Posted by Zorrofox View Post


Thanks mate. I actually know that and one is being supplied by the manufacturer of my O2 but "jring" appears to state a couple of posts previously that it might be beneficial to get a more powerful one for the O2 when it is paired with the Q701's. I'm just asking if that advice applies irrespective of what the actual mains voltage is.

 

Just look at the wall wart supplied with your O2 - it should have the specifications printed on it. If your mains is 240V it obviously must be 240V primary and should have anything from 12V to 20V secondary (12V flat is frankly not enough but the 12V nominal transformer specified by the designer has actually 13.5V or so) and 200mA or more.

 

If it says 200mA it might be a bit on the weak side with demanding headphones and high listening volume (although I'd think more like HE6 demanding) and 400mA might be a quick upgrade option. But I'd first test it and listen for bloated bass, which is usually a sign of an amp with not enough current.

 

Joachim

post #2304 of 5399

Well walter supplies 15V 500mA power so shouldn't be a problem..

post #2305 of 5399
Quote:
Originally Posted by jring View Post

Just look at the wall wart supplied with your O2 - it should have the specifications printed on it. If your mains is 240V it obviously must be 240V primary and should have anything from 12V to 20V secondary (12V flat is frankly not enough but the 12V nominal transformer specified by the designer has actually 13.5V or so) and 200mA or more.

If it says 200mA it might be a bit on the weak side with demanding headphones and high listening volume (although I'd think more like HE6 demanding) and 400mA might be a quick upgrade option. But I'd first test it and listen for bloated bass, which is usually a sign of an amp with not enough current.

Joachim

That's good info with a simpler explanation. It's not that I'm thick but the last time I had to look at numbers such as those above I was wearing shorts.

Quote:
Originally Posted by hekeli View Post

Well walter supplies 15V 500mA power so shouldn't be a problem..

Perfect! Thanks.
post #2306 of 5399
Quote:
Originally Posted by jring View Post
 

 

AKG K240 Sextett, K141 Monitor,  Beyer DT990  -  I also jury-rigged it to a Stax Energizer driving my SR-5 and Lambda Pro and it didin't sound bad at all. Common knowledge says those stax energizers want a few watts at least but for my listening levels I haven't heard a difference to using a power amp.

 

Joachim

 

The stock O2 has only +/- 12Vdc power rails, I cannot see how a more powerful adapter would do anything different.

post #2307 of 5399
Quote:
Originally Posted by JacobLee89 View Post
 

 

The stock O2 has only +/- 12Vdc power rails, I cannot see how a more powerful adapter would do anything different.

 

The difference is in the current that the power adapter can provide. But in terms of voltage...

 

BG


Edited by r010159 - 3/28/14 at 12:26pm
post #2308 of 5399
Quote:
Originally Posted by r010159 View Post
 

 

The difference is in the current that the power adapter can provide. But in terms of voltage...

 

BG

...there's nothing to be done, regardless of what you try, those 12V are an absolute limit (or you'll drive it into clipping).

post #2309 of 5399
Quote:
Originally Posted by Xenophon View Post
 

...there's nothing to be done, regardless of what you try, those 12V are an absolute limit (or you'll drive it into clipping).

 

Makes sense to me. :normal_smile :

post #2310 of 5399
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