[mikeaj]

Quote:

if you read the datasheet under the max rating chart, these regulators can be damaged.  the power protection is "fail safe" for catastrophic conditions, not continuous out of spec operation.  a short in the circuit post regulator will cause over-heating, but i'm also wondering if people are leaving in the batteries continuously along with AC power, and what is the current draw in this state.
 

It shouldn't be more than several mA to each of the batteries at full charge.  There's a Shottky diode and 220 ohm resistor between the 12V regulator and the battery (which should be above 9V at full charge).

 

[Paul Blythe]

Quote:

Ah... we were talking about different things, I was referring to the max voltage swing of the O2 which is 6.8 Vrms, you were referring to the voltage needed to achieve 110 dB peaks for the HD600, which is about 5.7 Vp-p.
 
 

Yep...

 ... Found the ref' point also..."SOURCE REQUIREMENTS: The HD 650 has a high impedance (300 ohms) and needs more voltage than most portable devices and PC headphone outputs can provide. Generally you need about 2 volts RMS (5.7 volts peak-to-peak) for wide dynamic range music at realistic levels." from nwavguy's review of the HD 650's.
 
So basically, the 650's aren't that hard to drive too very loud level's and the O2 is more than capable of driving the whatsit's of them. The 600's power requirements aren't that different from the 650's, iirc?

 

[fishski13]

Quote:

It shouldn't be more than several mA to each of the batteries at full charge.  There's a Shottky diode and 220 ohm resistor between the 12V regulator and the battery (which should be above 9V at full charge).

you're right.  i just found that 8mA should be the normal draw, but that with the battery depleted at 0V, you could be looking at 50mA.  assuming that each channel draws 24mA and the charging circuit draws 8mA, you're under 0.25W across the regs/resistors assuming 18V from the WAU16-400.  even when sitting right next to one another, they should be able to dissipate fine assuming that you're not charging a depleted battery.  

 

[shadow419]

Exactly, that's why most of the people that have built one have never reported the regulators getting hot.  I'd be more likely to think cheapskate got a dud part, or somehow "buggered" it up a little while doing the build.  Even if this amp isn't "perfect",  I would never call anything perfect, it still performs very well especially for the cost.

 

[kingpage]

It would be very hard for anyone to admit mistakes at this point. It'd be easier to just go with what's been said. Me thinks...

 

[khaos974]

Quote:

The 600's power requirements aren't that different from the 650's, iirc?

Almost the same.
 
 

 

[qusp]

Quote:

Yep...

 ... Found the ref' point also..."SOURCE REQUIREMENTS: The HD 650 has a high impedance (300 ohms) and needs more voltage than most portable devices and PC headphone outputs can provide. Generally you need about 2 volts RMS (5.7 volts peak-to-peak) for wide dynamic range music at realistic levels." from nwavguy's review of the HD 650's.
 
So basically, the 650's aren't that hard to drive too very loud level's and the O2 is more than capable of driving the whatsit's of them. The 600's power requirements aren't that different from the 650's, iirc?

yeah, something about this post seems familiar =D i dont get much more than half way on the amp i'm talking about which probably works out to just under balanced line level, or less than 2x regular SE line level (fullscale) which of course will be influenced by the recording, or the particular dac in question
 
HD600 are a lot closer than the folklore here would have you believe and in the electrical requirements pretty much the same. they are both 300Ohms, but the way the sensitivity is quoted/measured is different on the 2 models is different, so the difference is not as great as they would have you believe and people who need replacement drivers for hd580, hd600, hd650 get pointed to the same page..... from reports and including my own listening i would place the sensitivity at only ~2db, but the hd650 do seem a bit easier driven

 
Quote:

Exactly, that's why most of the people that have built one have never reported the regulators getting hot.  I'd be more likely to think cheapskate got a dud part, or somehow "buggered" it up a little while doing the build.  Even if this amp isn't "perfect",  I would never call anything perfect, it still performs very well especially for the cost.

 
what he said

 

[qusp]

and before anyone says balanced puts out 4x the power, do remember i'm talking voltage

 

[kiteki]

Quote:

Quote:

Originally Posted by Head Injury /img/forum/go_quote.gif
 
There is no indication of "harshness" in the O2's measurements. This gives us a few possible reasons for how you removed harshness:

1. Something in your O2 was faulty
2. Something else in your chain is harsh, and the changes to your O2 mask and distort that
3. There is a yet unmeasured phenomena at work
4. It's all in your head
    

 
I wish people would stop pretending this amp is some kind of reference design. I saw the O2's gain stage in a PDF for a TI opamp. It's a cool little amp to build and have a blast with but it's far from being a big time performer. In fact, the O2's performance makes me think someone cobbled together circuits from a variety of pdf's, measured them with a scope they probably bought at a flea market, and decided to "turn the audio world on end" with this new fangled concept of measuring things.
 
Don't get me wrong, I like the amp, I just think it's absurd how this amp has been placed on a pedestal, and I'll admit I was one of the people who initially was ready to call into question everyone else, but the fact is it's this amp that is wrong, not the rest of the world.

 

 
 

 

[Willakan]

Prays the above does not constitute approval.

 

[DRUB]

Quote:

Prays the above does not constitute approval.

+1

 

[qusp]

yes, what does that mean?

 

[kiteki]

 
It means
 

 
 

 

[Twinster]

Still like to be ambiguous Kiteki. From one thread to the other 

.
Quote:

 
It means
 

 
 

 
 

 

[JamesMcProgger]

I'm pretty damn sure it is not an approval...