I don't understand Audio Power Output?
Feb 24, 2014 at 1:50 AM Thread Starter Post #1 of 8

Smugsie

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So I understand almost everything required to survive in the audio world to properly amp my headphones.

Although the Sony website introduced me to something new. https://docs.sony.com/release/specs/NWZE474BLK_mksp.pdf

My Vmoda M-100's sound great out of my Sony E474's, but the bass is tighter and punchier through my odac/o2 combo. I'm trying to figure out what went "wrong".

 
Apparently I've read somewhere that the Sony E474 outputs 16ohms/mW, and the audio power output is 5mW+5mW
There's 30 levels of volume in the Sony Walkman.

My questions are: What does the Audio Power Output mean? Does it have any correlation to the output impedance? Does this mean my Sony Walkman can reasonably power the M100's?
 
Feb 24, 2014 at 2:35 AM Post #2 of 8
  So I understand almost everything required to survive in the audio world to properly amp my headphones.
Although the Sony website introduced me to something new. https://docs.sony.com/release/specs/NWZE474BLK_mksp.pdf
My Vmoda M-100's sound great out of my Sony E474's, but the bass is tighter and punchier through my odac/o2 combo. I'm trying to figure out what went "wrong".
Apparently I've read somewhere that the Sony E474 outputs 16ohms/mW, and the audio power output is 5mW+5mW
There's 30 levels of volume in the Sony Walkman.
My questions are: What does the Audio Power Output mean? Does it have any correlation to the output impedance? Does this mean my Sony Walkman can reasonably power the M100's?

The ODAC is going to be a better DAC then whatever DAC chip is in the 474BLK
The O2 headphone amplifier is better then the 474BLK's head amp.
So the ODAC/O2 can make headphones sound better then the 474BLK
 
You could try going thru every setting in the 474BLK, maybe there is a "bass boost" setting?
 
Feb 24, 2014 at 9:46 AM Post #3 of 8
  The ODAC is going to be a better DAC then whatever DAC chip is in the 474BLK
The O2 headphone amplifier is better then the 474BLK's head amp.
So the ODAC/O2 can make headphones sound better then the 474BLK
 
You could try going thru every setting in the 474BLK, maybe there is a "bass boost" setting?


Oh, so it has nothing to do with technical specifications, the ODAC/O2 is just simply a better sounding device?
If that's the case, you just answered my question :)

There's a bass boost setting, but it doesn't sound as tight when amping without even a little more amplification such as an E12.
 
Feb 24, 2014 at 12:25 PM Post #5 of 8
 
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
 
Feb 24, 2014 at 6:33 PM Post #6 of 8
   
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



Took me a little searches here and there to understand what you're saying, but it really did help a lot. If you don't mind me generalizing what you said; I pretty much got "Sony didn't provide enough technical specifications to verify anything" out of that, and it's just mainly a marketing tool.

I guess I'll email Sony and see what they say.

Although thanks a lot Protege for clarifying things.
 
Feb 24, 2014 at 9:39 PM Post #7 of 8
  Took me a little searches here and there to understand what you're saying, but it really did help a lot. If you don't mind me generalizing what you said; I pretty much got "Sony didn't provide enough technical specifications to verify anything" out of that, and it's just mainly a marketing tool.
I guess I'll email Sony and see what they say.
Although thanks a lot Protege for clarifying things.

I would assume the Sony 474BLK has to be careful how much juice it uses for the headphone amplifier, as it's battery powers more then just the head amp (DAC, screen, audio processor, etc) the 474BLK needs to make it's battery charge last.
Where as the O2 comes with two batteries and only has to power the amp.
 
Feb 25, 2014 at 3:30 AM Post #8 of 8
 

Took me a little searches here and there to understand what you're saying, but it really did help a lot. If you don't mind me generalizing what you said; I pretty much got Sony didn't provide enough technical specifications to verify anything out of that, and it's just mainly a marketing tool.

I guess I'll email Sony and see what they say.

Although thanks a lot Protege for clarifying things.

 
Not really marketing, but just the bare minimum since those specs don't really help them sell that device as much as, say, claiming that one of their A/V receivers makes 125wpc at 8ohms (when there's the possibility it was on one channel loaded), or say claiming that a 4ghz processor with 8cores really works great for games (when the problem is that the software on the games isn't utilized to run on that many cores - this isn't something that the motherboard controls on its own).
 
At the same time you have to consider design limitations. That player is very likely using a single integrated DAC and headphone amp chip, instead of using several specialized chips - DAC, output opamp, headphone driver - with consideration for size and battery life. Their S-Master chip if I understand it correctly is a better implementation of a single chip set-up, which is great for everything that isn't a low efficiency or too high impedance headphone, something constructed in such a way that hardly anyone would walk around in those anyway.  Regardless of what Sony's answer is the output power and THD are very likely as I've put in my earlier post; as well, if it's also coming from the DAC instead of just the amp's distortion, then Sony isn't likely to admit that they tipped up the bass response to a point that the amp is having trouble playing louder bass notes on those headphones.
 

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