[zilch0md]

  Does PHA-2 enough to drive LCD-2? I am still struggling between  hifi-m8 + D100 and PHA-2, because I want to play DSD but not sure about the amp of pha-2.
 
I've read a review online said that the PHA-2 performs quite well with LCD-3, but that's the only article I can find now. 

 

Power

1. Output Power : Maximum output (when using built-in lithium-ion battery):
   Approx. 165mW+165mW (8 Ohm, 10% distortion)
   Approx. 90mW+90mW (32 Ohm, 1% distortion)
   Approx. 25mW+25mW (300 Ohm, 10% distortion)

Source:  http://store.sony.com/gsi/webstore/WFS/SNYNA-SNYUS-Site/en_US/-/USD/ViewProduct-Start?SKU=27-PHA2
 
90mW into 32 Ohm is equivalent to only 58 mW into 50-Ohm LCD-2.
 
It might offer fantastic sound quality into more efficient headphones, but the Audeze LCD-2 would be stifled by the the PHA-2's weak output.
 
Audeze support has repeatedly recommended at least 1000 mW for the 50-Ohm LCD-2 and LCD-3.  
 
Their headphones sound "OK" on weaker amplifiers, but the bass control and dynamics greatly improve with more power.   A 15V-powered Meier Stepdance / 2Stepdance / QuickStep portable amp can deliver 900 mW per channel into 16-Ohms (or about 288 mW into 50-Ohms), and several LCD-2 owners have testified on the Meier Stepdance thread that great improvements to sound quality are had with 15V external power vs. running the Meier portable amps with only internal 9V internal battery power (where the Meier amps put out about 500 mW per channel into 16-Ohms (or about 160 mW into 50-Ohms).
 
In other words, a Meier Stepdance is nearly twice as powerful as the PHA-2 on its 9V internal battery, or more than four times as powerful on an external 15V battery pack or PSU.
 
I'm not just plugging Meier's amps, either.  There are plenty of portable amps out there that can blow away the PHA-2 in terms of power, including the iBasso PB2, which can weigh in at 2500 mW into 16-Ohm (or 800 mW into 50-Ohm), varying with choice of op-amps.  800 mW into 50-Ohm doesn't quite reach the Audeze recommendation of 1000 mW for LCD-2, and yet, it's nearly 14 times the 58 mW into 50-Ohm power output of the PHA-2.   Ray Samuels Audio, ALO, and Triad Audio all offer single-ended and balanced amps that can whoop the PHA-2.  
 
And, of course, there's the CEntrance Hi-Fi M8, which outputs something like 300 mW into 50-Ohms - more than five times the power of the PHA-2.
 
I'm actually a huge fan boy of Sony, but I am VERY disappointed in both the PHA-1 and PHA-2 specs.  HiFiMan HE-6 will choke on the PHA-2.  Audeze LCD-2 and LCD-3 will be lackluster.
 
Plan on using ultra-efficient headphones or IEMs with Sony's 15-mW (into 16-Ohm) Hi-Res Walkman offerings.
 
Plan on using efficient headphones with their 58-mW (into 50-Ohm) PHA-2.
 
The PHA-2 will be plenty loud with just about any headphone, but with the more power-hungry headphones, it will lack headroom-related traits (i.e. bass control and dynamics).
 
Again, I'm expecting to hear great reports regarding the sound quality of the ZX1 > PHA-2 pairing - but with efficient headphones.
 
----
 
All that said, he're what's really weird about the PHA-2's output power specs...  The PHA-2 uses a chip, called the Texas Instruments TPA6120, that's capable of outputting 1500 mW into 32-Ohm (or 960 mW into 50-Ohm) when given a 12V supply voltage, and a whopping 2000 mW into 32-Ohm (or 1280 mW into 50-Ohm), with a 15V supply voltage!  
 
See Figure 8, on page 8 of the TPA6120A2 data sheet: http://www.ti.com/lit/ds/symlink/tpa6120a2.pdf
 
Which begs the question:  What Vs (supply voltage) is Sony using with the TPA6120 in the PHA-2?  
 
Answer:  Per their specs page -   

1. Power Source : DC 3.7 V Built-in lithium-ion rechargeable battery

That's why the PHA-2's TPA6120 isn't putting out 2000 mW into 32-Ohms. That chip needs 12V for 1500 mW, or 15V for 2000 mW (into 32-Ohms).  The PHA-2 is using a one-cell, 3.7V battery.
 
The iBasso PB2 uses a 3-cell, 11.1V battery (with different op-amps, of course).  The RSA SR71B uses a four-cell, 14.8V battery (with different op-amps).  But the correlation is obvious: Weak battery = weak power output.
 
One last comment about the PHA-2's power output:  Notice that the spec includes these words:  "(when using built-in lithium-ion battery)"
 
This might have you wondering whether or not they increase the Vs (supply voltage) to the TPA6120 when the PHA-2 is connected to a higher than 3.7V external PSU.  The Centrance HiFi-M8 doesn't do this, but the Meier, RSA, Triad Audio, and iBasso portable amps do.  If you given any of those amps higher voltages from an external source (battery or PSU) than the respective voltages of their internal batteries, you will get more Watts out using the external supply than with the internal battery.
 
But no such luck with the Sony PHA-2 - they designed it to be charged from a 5V USB cable!  There's no way to supply the PHA-2 with higher voltages.  So there's simply no way the TPA6120 can reach its full output potential of 2000 mW into 32-Ohms (as either a desktop amp powered with a 15V PSU, or still as portable amp, with a 15V external battery pack such as the Energizer XP8000).  Nope, it's stuck with 3.7V power.  Oh well!
 

Is the idea to pair these components to be able to play hi-res and then provide more power with the pha-2 amp? How would you connect the two? Analog?

 
The interconnect between Hi-Res Walkman units and the PHA-2 is digital:
 
http://www.head-fi.org/t/680208/sonys-dsd-capable-pha-2-portable-headphone-amp-dac/180#post_9877733

 

[castleofargh]

I would have never guessed sony would give actual useful specs of their products.
very interesting post zilch0md. thank you.

 

[zilch0md]

Thanks castleofargh!
 
The smartest thing Sony did with the PHA-2 was to give it a digital input from their Hi-Res Walkman players AND an analog Line Out from its excellent PCM1795 DAC.  Together, these two features promise to deliver an easy-to-use, bug-free UI (in ZX1, for example) and a very capable portable DAC (in the PHA-2), for use with the portable headphone amp of our choice, for those who want to drive inefficient headphones.  
 
For power-hungry headphones, I'm imagining a stack that includes the ZX1, the PHA-2, an SR71B, and an Energizer XP8000 (to supply both 5V and 16V power).  Personally, I have no use for its hamstrung amp section.
 
The forthcoming FiiO X5 will have pretty much the same DAC, a PCM1792, but which actually has better THD + Noise specs than the PHA-2's PCM1795 DAC.  Unfortunately, FiiO's UI will will be a complete joke compared to the UI of a Sony ZX1 (going on recent history with the FiiO X3).  It will, however, have TWO microSD card readers, supporting the SDXC format!  For a lot less money than a ZX1 + PHA-2, when the intent is to use the Line Out to a more substantial amp.
 
----
 
But I can't stand those buggy UIs from HiFiMan, FiiO, and iBasso - forever waiting for the next firmware download, with the products getting discontinued before they ever fix all the bugs.  This is why I'm waiting for the $999 Sony PCM-D100 recorder/player, to be released "in early 2014" - perhaps the ultimate card-reading, DSD-capable, portable player, with both optical and analog Line Out to the amp of my choice.  (I'm not intererested in its headphone out -  rated at 25mW into 16-Ohm.)   Yes, it has a (bug-free) UI that's meant for making field recordings, not for playing songs (navigation by folder-browsing), but $999 is a lot less money than what I would pay for a ZX1 + PHA-2 - and not only will I get a card reader, I'll be able to make Hi-Res recordings!  And... it comes with a wireless remote that can be used for both record and play!  Joy!
 

 

 

 

 
 
See more info on the Sony PCM-D100, here:  http://www.head-fi.org/t/679589/leak-sonys-new-portable-linear-pcm-recorder-pcm-d100-upgrade-of-the-famous-d50s/40_20#post_9932805
 
Mike

 

[One and a half]

Thanks zilch0md for the numbers. There are a lot more amps out there with more power than the PHA-2, none of them accept DoP or native DSD. For its intended use of connecting to a PC with Jriver playing DSD on the road or in a plane is a dream come true in such a small package. No way in the world will the LCD-3 go on the road, it stays at home, the PHA-2 can drive it, but to what extent is really debatable, keeps forums like this alive, for sure.
 
To get the most enjoyment out of an LCD-3, it needs an AC powered amp with grunt, would I choose the PHA-2 for desktop or home use exclusively, no. The PHA-2 is a portable headphone amp (PHA), and the performance needs to be taken into account, I think you ask too much. If you want more power, by all means use the PHA-2 as a DSD DAC and use the line out to drive something else, which it is quite capable of doing.
 
Looking at the figures, 1mW for the LCD-3 can produce 91db, how much power do you really need?

 

[castleofargh]

well for orthos there is how loud can I go, and how the screw do I control that heavy magnetic plate? if they're such a pain to drive it is because they need a lot of everything for sound level and damping, when a 600ohm dynamic driver asks mostly for a lot of volts.
 
but I have to agree that audeze might not be the first to come to mind when you think portable headphone ^_^.

 

[RIQUE]

  Everyone has perceptions differently. A fine DAC to me is say the Mytek, or EXA series. An exceptional DAC is PD, Meitner, Luxman. Same with amplifiers, you regard the PHA-1 as a fine amp, I have no problem with that, it's just the difference between the two, I own both, is very dramatic fed with a DSD file.

Well you see that is the problem you are not comparing  apples to apples. Your are comparing a DSD file on the PHA2 to MP3 on the PHA1. Of course its
going to sound better but not of its own merit but rather by use of a higher quality format.  A fair comparison would be to use same file types on both amps. And considering that the PHA2 and PHA1 amps section is the same on both....sound will probably not be all that dramatically different. 

 

[bmichels]

Any availability news or REAL tests of the Sony Walkman NW-ZX1 with 128Gb that is supposed to pair with the PHA-2 ? 
 
More precisely, I would like to know if it offer a real USB-Out that can be used, at 24/192 kHz without Downsampling, with another external DAC ?  
 
if yes, then What cable to use  ?  A Sony proprietary USB cable ? 
 

 

[f198]

Very detailed PHA-2 review from Japan:
http://av.watch.impress.co.jp/docs/review/review/20131108_622608.html

 

[zilch0md]

Thanks for that link!  
 
Having read the Google translation to English, I didn't see any mention of compatibility with various headphones, in regards to the PHA-2's power output.  Nor was there any mention of the analog Line Out.
 
I strongly suspect that, with the right headphones, the ZX1 > PHA-2 will offer phenomenal sound quality (not to mention a wonderful UI, the likes of which simply isn't available in DAPs from other manufacturers).
 

Spoiler: More whining about PHA-2 power output specs

For me, going only on the published specs, as recently discussed in this thread, I still see the PHA-2 as a "cure" for the 15mW into 16-Ohm output of the ZX1 (except for efficient IEMs) and its analog Line Out as a "cure" for the PHA-2's 58mW into 50-Ohm output (except for efficient headphones).  
 
[size=1em]For my headphones and my tastes, it would be nice if Sony would make a less-expensive, amp-less version of the PHA-2 - with just the PCM1795-based DAC, accepting digital input from the ZX1 and still offering the analog Line Out. [/size]

 
Mike

 

[Alligator]

Just picked up the PHA-2 from PriceJapan.  Now I need an English manual.  Anyone have a source?

 

[HiFiGuy528]

Just unboxed mine.  Check it out.
 

 

[Alligator]

Were you able to find an English manual? Although the device is pretty easy to use, I would like to read things over so I don't miss anything.

 

[DrSheep]

Just read the English manual for the 1 as they are pretty much the same. Besides it is so simple that I doubt you can mess it up. The only thing different is DSD support which you might need drivers.

 

[RAFA]

  Just unboxed mine.  Check it out.
 

 
Very nice, Thank you for this! I hope soon that you will provide some SQ impressions

 

[zilch0md]

I can't help pointing out that at 1:15 into the video, he skips right past making any comment about the power output specifications, but I appreciate the video, just the same.