Originally Posted by Nec3
Oh, so it has nothing to do with technical specifications, the ODAC/O2 is just simply a better sounding device?
If that was the case then the only thing "better" is a placebo; a device can't really sound better unless it is technically better as well. The real problem really is deciphering manufacturer specs, which in some cases is just so screwed up and biased to provide a good looking output* short of lying, and audiophiles with an engineering degree (usually those who sell DIY amps) go out of their way to hook up gear to testing equipment to verify or decipher stated specs. However, in certain aspects of audio there are more reasons for bogus specs, so you can expect a shelf system with a huge red sign on it that says, "4,000Watts PMPO!!!" but for a portable player I don't think the marketing psychology is the same. For portable devices, they use any integrated audio chip, then slap on an "iPod" or "Android" o the earphone, or some other clue that the earphone's efficiency is high enough.
That said here's one way of looking at those specs. I'm assuming Sony doesn't provide the THD at 5mW, so let's assume that isn't very linear or it has a very high slope when graphed. It might be making 0.1% THD at 5mW on 16ohms, whichh for example can be at 30% (arbitrary and for explanation of the idea, not the specific situation), but if it can output 10mW to the same load to get the earphone to your usual listening level, it might be making 5% THD. Meanwhile, let's say the O2 can not only make a lot more power than that, but assuming you are listening at the same volume levels, at 10mW the THD is only 0.01%. Add to that a dedicated power capacitor (mini versions are available on most "audiophile" players to mimic a separate amp) and power supply that gives it a lot of dynamic power. Then there's the ODAC, which together with the O2 might have a much flatter response (try EQ-ing to boost bass on any system and a weak amp will run out of steam).
*For example, many A/V receivers can be as vaguely rated as, "Output power: 185 watts @ ohm." It doesn't clearly state other parameters that affect output (see below), so if the circuit particularly the power supply isn't a good design and casual HT buyers just want to know if they can rock their windows with this thing, they'd measure it this way and say that and technically they aren't lying
1. How many channels are loaded? It can measure a lot more with only one speaker hooked up.
2. What distortion level? Squeezing more power out of an amp means more distortion, the question is how much of the output signal is total harmonic distortion (or whether it is at an audible level)
3. Headroom and current? If you're using too much of the RMS power, especially at the lowest imepdance the amp is stable at, you might lose reserve power for dynamic passages
Edited by ProtegeManiac - 2/24/14 at 9:27am