Saturday, May 23, 2015

Sony MDR-Z7 Headphones and PHA-3 Portable Headphone Amplifier

Sony PHA-3 Portable Headphone Amplifier


The Sony PHA-3 is a compact battery powered DAC / headphone amplifier. Size-wise, it is the perfect partner for the NW ZX-2 walkman and provides the additional drive required for more difficult headphone loads. 


The palm sized PHA-3 is aluminum finished, with the volume knob and headphone jacks on one end, with inputs, line output and the power jack on the other side.

The front panel has 3 LEDs that indicate high frequency sampling rate (anything above 48 kHz), DSD operation and power / charge status.

Two rubberised strips on both the top and bottom of the unit provide the unit with a bit of extra grip to prevent the unit from sliding on flat surfaces.

Measuring  80 x 29 x 140.5 mm (WxHxD), the PHA-3 weighs a very healthy 300 g.

The PHA-3 is well specified with playback of file resolutions of up to 32 bit / 384 kHz sampling rate supported via USB connection, or 24 bit / 192 kHz via the Toslink optical jack. DSD is supported at both 2.8 MHz and 5.6 MHz.

USB input is via either a micro USB port or a type A socket.

A line input is also provided to allow the PHA-3 to act as a headphone amplifier with analog signals.

The headphone amplifier is robustly specified at 100 mw per channel (32 ohm loads at 1% distortion) for normal operation, and 320 mw per channel for balanced operation. 

The PHA-3 has a built-in lithium-ion battery which is charged via a micro USB jack. Battery life is specfied at 5 hours if balanced operation and the DAC is used. Using the PHA-3 as a headphone amplifier only (i.e. via the analog input) lengthens the battery life to 28 hours.

One headphone jack (3.5mm) is provided, with a second pair of jacks (3.5mm also) for balanced operation. 

Two side mounted switches control gain and DSEE HX (Digital Sound Enhancement Engine) which upscales lossy music files.


The PHA-3 is generally easy to operate. The unit is switched on via the volume knob and the power / charge indicator will flash briefly to inform the user of the battery level (3 flashes indicating full charge). 

The unit charges fully in about 10 hours if charged via a computer USB port. An optional AC adapter shortens charge time to 6 hours.

By the way, Sony is not joking about the battery life. I obtained an average of about 4 hours of use from the PHA-3 using both the DAC and balanced operation. Better bring along a battery charge bank for longer journeys !

If you are using the PHA-3 for desktop use, it can be powered continuously. Sony's manual states that the PHA-3's battery is not charged unless the unit is switched off. My personal experience suggests otherwise. I discharged the battery until it was nearly empty and then hooked it up to a computer USB port. I managed to get about 50 % charge after about 10 hours. It definitely charges when switched on, albeit slowly.

Connecting the PHA-3 to various computers around the house and both iOS and Android mobile devices for PCM playback was fuss-free. For DSD playback, I could only get the PHA-3 to work reliably via the Sony provided software player. Fiddling with Foobar got me nowhere, while I managed to get a few seconds of playback via Pure Music, followed by loud bursts of static. I did not have a compatible Sony Walkman, so I am not sure whether the PHA-3 can play back DSD files directly from such devices.

In terms of drive ability, the PHA-3 had no problems with either a Beyer DT-880 (250 ohm version) or Sony MDR-Z7 (for both normal or balanced operation) to ear splitting volumes. 


The PHA-3 sounded great as a DAC / headamp.  Bass was authoritative and full, while high frequencies were extended and clean. Midrange tone was slightly laidback and sweet though. Resolving quality was quite good and the low level details in my usual test tracks were reproduced without any issue.

Pairing with the Beyer DT-880 proved to be a great match. The DT-880 can sound overly bright and lean with the wrong source and amplifier match. The midrange sweetness and full bass of the PHA-3 proved to be a nice counterfoil to the DT-880's fast and analytical character. 

The PHA-3 performance in balanced operation was exemplary. The MDR-Z7 was the only headphone I had on hand with appropriate wiring for the PHA-3. In this case, the Z7 gained additional authority and clarity in bass lines. There was also an improvement in speed and separation, especially during busy mixes. I would even dare to suggest that the PHA-3 and Z7 were truly made for each other.


The PHA-3 is an interesting animal. It has a great DAC and headphone stage, but battery life is frankly underwhelming. What really sold me on the PHA-3 was balanced operation.

The review sample was kindly supplied by Sony Singapore through it's media partner, Waggener Edstrom.

Recommended Consumer Price - SGD 1,199

Sony MDR-Z7


Readers may wish to refer to my earlier article that featured the MDR-Z7, as it provides some insights into its design (click here for the earlier article). 

The kind folks at Sony had offered the Z7 together with the PHA-3 for purposes of this review, but I had already purchased the Z7 sometime back, so a review sample was not necessary.


The Z7 is Sony's newest flagship headphone. Sporting massive 70 mm Aluminum-coated Liquid Crystal Polymer diaphragms, the Z7 has a rated frequency response from 4 Hz to 100 kHz.  

Sensitivity is rated at 102 db/mW, with an impedance of 70 ohms (at 1 kHz). These specifications suggest that the Z7 is quite easy to drive, which was borne out by listening tests.

With a weight of 335 g, the Z7 is of moderate weight, but the physical size of these cans means that the Z7 is happier at home than on the go.

Sony thoughtfully provides a 3 m silver-coated OFC cable, as well as a shorter 2 m balanced cable. Cabling attaches to the Z7 via twin locking 3.5 mm plugs.The balanced cable is terminated on the source end via twin 3.5 mm plugs too. In case you are wondering why Sony did not terminate the balanced cable in a more common way, like twin 3 pin XLR plugs, or a single 4 pin XLR plug, the answer is obvious once you look at the pictures of the PHA-3 above.

Despite the locking sleeve, any ordinary 3.5 mm plug will fit nicely into the jacks on the headphone end. 

The Z7 is a closed design. Twin vents (on the top and bottom of each earcup) result in some leakage of sound, albeit only a high volumes. 

In Use

Comfort and fit is first-rate. The soft leather-feel earpads are some of the most comfortable pads I have used. They do heat up very fast in tropical weather, and periodic rest is required even in air-conditioned environments.

The adjustable headband has numbered graduations internally, making it a cinch to revert back to your preferred adjustments quickly. The headband fit my smallish head well, without exerting too much pressure on either my ears, nor the legs of my eyeglasses.


I paired the Z7 with a variety of headamps and sources I had on hand, before settling for the PHA-3 and a Violectric V281 (used as both a headamp and DAC). As I did not have the right cable, I could only use the normal outputs on the V281 rather than the balanced drive outputs.

The first thing that grabs your attention is the bass. The Z7 has powerful and thumpy bass lines. The problem is that the bass frequencies overwhelm the rest of the frequency spectrum and have a slight lack of control.

The midrange has a slightly laidback and sweet presentation. High frequencies are extended but well-behaved. Subjectively, the high frequencies seem to have less prominence compared to some of my other headphones. Initially I thought the Z7 sounded a bit dark and rolled-off, but this depended on the bass content of the track in question. The Z7 sounded wonderfully open and detailed on violin solos and very much less so on pop and rock tracks.

Staging wise, the Z7 is above average with a spacious soundstage (no doubt with some assistance from the angled drivers), and very good detail retrieval. 

Moving on to balanced drive, this is where the Z7 shines. With the PHA-3, the issues I had with the bass were largely addressed, with the low frequencies gaining tightness, control and explosive dynamics. Similarly, an increase in speed and incision lifted the midrange and treble to a faster and closer to neutral presentation. 

Notwithstanding the above, the Z7 (especially as a flagship model) is not a neutral headphone. My ownership experience so far parallels that of the Audio Technica ATH-W5000. Some tracks will leave you incredibly frustrated, while selected tracks will leave you in sonic bliss. Thankfully, balanced drive made the ownership experience more pleasurable than otherwise.


The Z7 is an idiosyncratic headphone - a detailed listen should make it clear whether you like it or not. However, in order to fully exploit it's capabilities, balanced drive is mandatory.

Recommended Consumer Price - SGD 899  

Sunday, May 17, 2015

Nola Boxer S1 Speakers


Many years ago when I was a wee little lad, I came across the most interesting looking speaker at a dealer's shop. The speaker was conventional rectangular box, but had an externally mounted midrange and tweeter, housed in what looked like a flat cut-out of a person.

"What are those ?", I asked innocently. The dealer in his usual gruff manner replied, "Alon speakers." I did hear them off and on for the few years that they sat in the shop. Nice speakers. 

Fast forward to the present, and Alon is no longer in business. However, Carl Marchisotto, principal and designer of Alon, now designs under a new company - Nola (Alon read backwards). 


The Boxer S1 is a 2 way bookshelf speaker that is part of Nola's Boxer Collection. The cabinet measures 15 1/2 inches (H) x 8 inches (W) x 11 1/2 inches (D). Rated impedance is 8 ohms, and frequency response is specified as 44 Hz - 28 kHz. Sensitivity is high at 90 dB.

The 6.5 inch bass driver utilises a laminated pulp cone, while the high frequency unit is a silk dome tweeter. The tweeter face plate incorporates a shallow wave guide and a felt ring to control diffraction. A detachable black cloth grill is supplied.

The S1 is a bass reflex design with a rear firing port. A single pair of high quality binding posts are located on the rear panel of the speaker. It is worth a mention that the terminals are mounted directly through drilled holes in the cabinet, and not large plastic terminal trays used by much of the competition.

Compared to the base model Boxer, the S1 gains Mundorf oil caps in its crossover and internal Nordost mono filament wiring. 

The review sample I received was finished in a glossy piano black finish.

The cabinet was not as rigid as I would have liked, with a lively response to the audiophile knuckle rap test. The quality of the supplied grills were also not up to mark with the rest of the cabinetry work. They imparted a veil over the high frequencies and were left unused in the box during the review period. 


The S1 is positively setup friendly. An initial placement on my 24 inch Partington Dreadnought Broadside stands about 6 feet apart sounded fine, and a little bit of adjustments in placement and toe-in (about 15 degrees inwards) completed the setup process.

Choosing partnering equipment for the S1 was similarly drama free and I got good results with both my Gryphon Diablo integrated amp and Job 225 power amp. Both amplifiers were fronted by a Antelope Audio Zodiac Platinum. In the case of the Job 225, the Antelope's excellent volume control stage handled preamp duties. I had a slight preference for the Gryphon, and used it for most of the review.

Sound Quality

The S1 was tonally on the warmer side of things, with a large and musical presentation.

Bass quality was good with weight and a nice bloom that gives the S1 a scale that belies it's physical size. I did notice on certain tracks though, a slight trace of colouration in the mid-bass. This was not always noticeable and seemed to occur only at certain frequencies. Cabinet resonance at play perhaps ?

Midrange deserves a special mention with the S1 reproducing the midrange with one of the most liquid and buttery smooth presentations I've heard in its price range. It reminded me very much of the tone from a good paper-in-oil capacitor. This gave vocals an anlogue and grain-free presentation although there was some trade-off with microdetail.

Interestingly, the S1's high frequency response was extended, clean and quite prominent. This gave the S1 a "U-shaped" tonal balance. I've heard plenty of smooth performers, usually to the point of boredom (especially if the treble is rolled-off). However, the S1 manages to sound smooth and laidback, while having a certain amount of liveliness, sparkle and air in the upper registers.  

In terms of staging, the S1 presents music with a slightly forward perspective, almost like sitting in the fourth or fifth row of seats in a concert hall. Soundstage width is good, but with some truncation in depth and height perspective.

Imaging was also good, albeit not to the superlative degree of the KEF LS50, or the Sony SS-NA5ES which I recently reviewed. Image sizes were slightly larger than normal. 

Resolving power was good on the top end of the frequency spectrum, with some loss of microdetail and articulation in the midrange and lower frequencies.

Listening to jazz quartets as an example, the performers sounded "big" with impact from the double bass, low piano notes, and the kick drum. The brass instrument had a warm and laidback glow, while the percussion work on the cymbals rang loud and clear.

Moving to violin solos, the instrument had a fuller tone than usual, with a sweeter tone and less "bite". Similarly, vocalists had a chestier quality, and singing techniques like vibrato did not come through as clearly as they should.


The S1 is a very enjoyable and musical speaker. It may not be the most neutral or detailed speaker around, but it sounded good across a wide genre of music. It made an admirable attempt to communicate the music in an engaging fashion, regardless of the quality of the recording. 

If you are looking for a speaker that errs on the warm and forgiving side of things, the S1 will likely please. It is a fuss-free speaker that will just let you sit back, put your feet up, and relax while enjoying your music. It's been a while since I had so much fun.

While I did find the S1's performance compromised in several areas, I found the overall strengths of the S1 to outweigh it's shortcomings. 

The Nola Boxer S1 is carried locally by Horizon Acoustics and lists for SGD 3,450 (with stands). The review sample was supplied by Horizon Acoustics and thanks goes to K.M. Poon for making the necessary arrangements.

Horizon Acoustics

144 Upper Bukit Timah Road
#03-15 Beauty World Centre
Singapore 588177
Telephone : 91259149
Website :