Sony PHA-1 Headphone Amp

I tested with various headphones and finally decided to pair it with a V-Moda M100.  After using for a few days, they seemed to be made for each other.


 
The headphones can produce the detailed music from the Sony amp - throbbing bass (you can feel the skin of the drums!), natural voices and clear notes from the instruments.  You can know the location of the instruments.  The bass does not overwhelmed other frequencies. Peaks and valleys of the music do not break nor hiss - they are helped by the quietness of the background.  I could not hear electrical hiss, the amp is so unbelievably quiet and as a consequence enhanced the music and vocals.
 
I brought them to a few hi-fi enthusiasts and they were astounded!

Overall Impressions 
 

The Sony PHA-1 is a great option in the few selections that one has for idevice DAC/Amps. Its been around for over a year now and with the news of the now released PHA-2, the predecessor of the PHA-1, the price of the PHA-1 has dropped quite a bit. For a while it hovered around the 400 dollar price point, but now it can be gotten around $330-350, making it one of the most affordable options for the idevice dac/amp. Having had these for a little over two months now, I thought I'd give these a little love and share my thoughts with the hope that, just because the hype is currently around the PHA-2, this nice little device wont be forgotten.
 
I'm currently running these with my Asus zenbook via USB, iphone 4S, or ipod classic gen 7 as source via LOD to the PHA-1 with a toxic cables silver poison LOD to USB cable, with heir audio magnus cable to my beloved Aurisonics ASG-2 iem.
 
Design:
I've tried a few idevice dacs or amps, more precisely the Fostex HP-P1, V-Moda Vamp, and the original algorhythm solo (still hoping to try the hifi m8 and theorem 720!). In terms of design, the sony is still the best, and honestly by quite a HUGE margin. Every little thing that sony implemented on these is really just better than its competitors.
 
The little rubber strips that run along the top and bottom of the device prevents the housing from rubbing against the table or the DAP it's attached to. It also stabilizes the device and keeps it in place.
 
The protective silver chassis that protects the volume knob and the input and outputs, often called the "roll cage" i believe, though annoying to some, is also a well designed extra bit of protection for the device. I've heard that they can be removed if someone is really that against them but Ive never had a problem with them myself. They really add extra protection to the front of the amp and theyre very sturdy. Its clear that that volume knob is not about to get touched by ANYTHING.
 
Another great design, and probably the coolest, and in some ways, the most "revolutionary" aspect that this amp brings to the market is its rubber clasp system. Instead of rubber bands that are sometimes hard to get around both the amp and the DAP, they created a clasp system that Im sure most people are aware of. The amp has ridges on the side that locks the rubber strips in place, and one simply has to put the strip over the DAP and lock the strip in the other side of the amp too and the DAP and amp will be bound nicely together. Its MUCH quicker and easier to use than the traditional rubber bands.
 
Another great freature of the PHA-1 is just how versatile it is. It is compatible with idevices, walkmans, and many DAPs. Along with that, its also compatible with PC or mac and acts as an external USB soundcard. Of course, more and more devices are becoming more versatile, but very few compete with the price that sony currently offers with the PHA-1 (for example, theorem 720 and hifi m8 both being over double its price).
 
One gripe i do have to mention is the lack of a line out. I dont think the PHA-1 offers an option to run a signal from the internal DAC directly out to a different amp. I really wish that was possible.
 
One other thing to mention is the channel imbalance for sensitive iems. And yes it can be a deal breaking problem for some unfortunately. With my ASG-2, which are fairly sensitive, i did have channel imbalance problems as i tend to listen to music at lower levels. But after implementing soundcheck on my itunes and my iphone 4S, the overall volume of the music decreased and i was able to turn the volume up, which eliminated the problem completely. So possibly a problem, but not something that cannot be solved (really hoping the PHA-2 is be different).
 
When it comes to design, i feel like sony pretty much nailed it in almost all aspects besides a few small complaints.
 
Battery Life:
Battery life is where i wish sony could do a little better. These have respectable battery life, very much on par with other similar products on the market. But for an international traveler who has to fly from Taiwan to the east coast of the US, a trip easily up to 20+ hours, the 6 hour battery life on these, or ANY idevice DAC/amp for that matter (except for the newly introduced theorem 720), is simply not enough. They are enough for my drives to Chicago but im still hoping for an improvement in battery life.
 
EMI:
Some amps will suffer from EMI especially when theyre being paired with a phone. Never had a problem with the Sony PHA-1. Absolutely none. Please do share with me if you experience EMI with these.
 
Sound:
And now we get to probably the most important part of anything on this website. How do they sound? I can say with a bit of confidence, that theyre pretty darn good at their current price!
 
Switching from the audio jack from an ipod to the PHA-1 is a pretty clear and obvious difference. Soundstage is very much expanded with much more 3 dimensionality. Detail retrieval is on a different level, and the dry, cold, sound of the iphone is replaced with a much smoother and enjoyable sound. 
 
The overall sound of the PHA-1 can be described as being relaxed and laid back. A sound that's very easy to enjoy, and with a very nice and dark background.
 
The sound of the PHA-1 is very neutral. No frequency stick out in particular to my ears. Bass is precise and has great depth to its slam, mids are smooth and flat (could as for a little more refinement), while the treble gives good detail but are never aggressive (just to sum it up real quick).
 
Soundstage is nicely implemented. Its fairly 3 dimensional (though not quite at the level of the HP-P1) with great width in particular. As stated earlier, the sound is more laid back, and instruments are further away than Ive become use to with the previous iBasso amp that i was using. I personally feel that the vocals are often just a little too distant and can lose a bit of intimacy and get mixed into the background. In particular though, that's more of a problem at lower volumes. Cranking up the volume knob eliminates the gripe i have of that.
 
Imaging is good but not stellar. Instrument placement and separation are both excellent, but I could ask a little bit more from the precision of the instrument placement.
 
The detail retrieval, also stated earlier, is a good step up from the ipod. The sound is much cleaner than an ipod, much less congested, and also much smoother sounding. The complexity with drumming and guitar in power metal for example, is very well defined and clear sounding with the PHA-1, while the ipod falls behind by a large margin. Comparing again to the HP-P1, which is my favorite of idevice DAC/amps that ive been able to try, its still not quite there in comparison however. With an MSRP originally of 600 dollars, I really wish that these had detail that is almost on par, if not on par, with the HP-P1. But remembering that theyre currently priced below 350 dollars, all I can really do is tip my hat to what it can do at the price that its now being offered at.
 
Conclusion:
The PHA-1 is a great amp that offers a lot of versatility with great sound at a price that is much more attractive than many of the other products that fit a similar niche. At the MSRP of 600 dollars, I really dont know how i could recommend these. With the likes of the fostex HP-P1 with MSRP of 650 dollars and the Hifi M8 being well regards for 700 dollars, I dont see much competition or demand for the PHA-1. But now cut the price of the PHA-1 in half, and suddenly you have a deal that cant be ignored.
 
The Sony PHA-1 with its flexible number of uses, amazingly well thought out design, and good sound, fulfills a role as a strong contender as a mid tier idevice DAC/amp with a great price, or any DAC/amp for that matter, and I would absolutely recommend it. I definitely hope that people will still consider it as an option despite the presence of the PHA-2.

Update: it turns out to be my F807 having a rather weak line out and not the fault of the PHA-1.  Therefore please ignore my comments about the gain issue and I am bumping up my rating from 3 to 4.
 
Ok here is my take on the Sony PHA-1 along with their F806 Walkman and the Sennheiser Momentum, and to be honest, I think some of you may not like it…
 
Here is a bit of background, the PHA-1 is MSRP at $600, but I paid for mine at $400 from Amazon, and this is my baseline on judging its value. However, most of you should able to find it for around $350 if shop around.
 
My bottom line for this little wonder is that it does a good job as a DAC with good amount of features, but as an amp, not so much.
 
Let’s talk about its DAC first, which is asynchronous and can operates at 24/96, just like the AudioQuest DragonFly (MSRP $250), and they sounded almost identical to each other at the same volume with my V-MODA M-100 during A/B testing. The PHA-1 performs equally well with my iPods compares to the V-MODA VERZA due to the digital amp and it shows.
 
However, the same cannot be said with the analog amp, which is where the PHA-1 falls apart.
 
Since the PHA-1 is a Sony product, it supports their Walkman line of DAPs by providing a LOD cable, which I paired with my F806. To my surprised, I LOST volume at low gain by about half using the PHA-1 vs. straight out from the F806. Both of the Sennheiser Momentum and V-MODA M-100 are low impedance cans at 18 ohms and 32 ohms respectably, and they both performed very well with the V-MODA VAMP and VERZA in low gain at 1/3 volume dial. Since the VERZA and the PHA-1 power rating are comparable to each other, I fully expected that power and volume wise they would be similar, which unfortunately is not the same. Compare to the F806 set at 35-40% volume, at low gain, I have to set the PHA-1 to at least 50% in order to get a similar level of volume back. Of course this is not exactly a problem for me, as once I switch to high gain, I can get the same level of volume at 1/3 dial just like my VERZA at 1/3 dial in low gain. However, I foresee problems with higher impedance headphones with this amp in analog mode.
 
But this begs the question: why would you buy the PHA-1? If you want to use it for your PC/laptop, then the AudioQuest DragonFly seems to be a much better choice as it is cheaper and much smaller; if you want to use it for your iDevices, then at MSRP you can get the Fostex HP-P1, V-MODA VERZA, or the latest and greatest VentureCraft SounDroid Typhoon for even less; if you want to use it for a Sony Walkman or other DAPs that only has an analog LOD, then there are so many better and cheaper alternatives that makes the PHA-1 a moot point. The situation that the PHA-1 will be viable is that 1, you can get if for much less than MSRP; 2, you are moving up from FiiOs and the like but don’t want to pay $600; 3, you want an all-in-one device and don’t have other DAC/AMP that I mentioned or similar above; 4, you want to stick with Sony for your Walkman.
 
I might seems to be overly critical to the PHA-1 and I think I am, and to be fair at $350 it is a good buy for a DAC/AMP with asynchronous USB at 24bits/96kHz and reasons I mentioned above. And future models and variants will only get better.
 
One thing that might save me from returning the PHA-1 is that I might work with the F806 in digital mode since that series of Walkman are Android based. I was going to test it but I couldn’t found my female USB to micro USB adapter. However, even if this works, the setup is not going to be pretty, as I have yet to see a short WM-PORT to micro USB interconnect anywhere, plus the V-MODA VERZA officially supports Android and it will be more likely to work with the F806. So if the testing works out, at $350 this will be a great buy for all you F806/807 owners.
 
I know I left out a lot of other stuff like sound quality, but I think it will not be necessary for me to repeat the findings from other reviews. Feel free to pm or post if you got questions, and I will try to update the post once I get some decent pictures.
 
Update: I just found out that there is a WM-PORT to female micro USB adapter from Sony model WMP-NWM10 for around $10-$15 bucks, and with this you can make your own interconnect to your favorite DAC/AMP that supports Android. I am going to hunt one down and test it out.
 
Setup: Top: iPod Touch 1st Gen; Middle: Sony PHA-1; Bottom: Sony NW-F806 plus Sennheiser Momentum.

 
Silicone soft clips up close. They work pretty well on the rail system. However, it only works on the top but not the bottom, hence the bands for my double setup.

 
Sony NW-F806 need to connect to the PHA-1 via analog in from the WM-PORT with the included cable. Tested the connection from WM-PORT to the mini-USB port and failed. Technically the PHA-1 support PC connection via mini-UBS, so I was hoping it will work for Android like the V-MODA VERZA. Too bad that I tested the F806 on both and they both failed to connect...