A real head for music

Sony PHA-1 portable headphone amplifier is built for serious music lovers on the go. It functions as a two-channel high resolution DAC (digital-to-analogue converter) combined with a high-quality headphone amplifier.

To ensure high quality sound, it can receive digital audio signals from your iPod, iPhone or iPhone through a provided 30-pin USB cable and then the signal is converted to analogue sound at high sampling rate and is amplified and turned into music through a pair of headphones plugged to PHA-1’s stereo mini jack.

Receiving digital audio signal directly from your iPod, iPhone or iPad yields better sound quality than getting the analogue signal from your music player’s stereo output.

The PHA-1 supports maximum audio sample rate and resolution of 96 kHz/24 bit and its amplifier can drive headphones with very high impedance, which normally cannot be used with a mobile phone or portable music player without an amplifier. The amplifier supports headphone impedance of 8 ohms to 600 ohms. It provides a side panel gain switch that supports high impedance or low impedance headphones.

It uses high slew rate Texas Instrument TPA6120 headphone amplifier and its DAC is high quality Wolfson WM8740. The PHA-1 has isolated analogue and digital circuits to minimise unnecessary internal electrical noise.

Its built-in Lithium-ion battery takes about 4.5 hours to charge with a micro USB port. The battery life allows the PHA-1 to be used for about five hours when connected to an iPhone or iPod. But if you connect the PHA-1 to a portable music player using an analogue stereo mini cable, which is also provided, the battery life can last about 10 hours.

The PHA-1 is professionally built in a durable aluminium enclosure with zinc alloy cast bumpers to minimise external interference and protect the volume control.

With the built-in micro USB port, the PHA-1 can function as a USB sound card for your MAC or PC computer.

When used as a USB soundcard, it supports up to 96 kHz / 24-bit frequency response with the signal to noise ratio of 96 dB. But when connected to an iPod, iPhone or iPad, it supports 48 kHz/24-bit frequency response with signal to noise ratio of 96dB. But when used with analogue stereo input, the frequency response is 10 Hz to 100 kHz with signal to noise ratio of 110 db.

When I connected it to my Windows 7 PC, the windows automatically installed the driver from the PHA-1 automatically and Windows 7’s sound system automatically selected the headphones (PHA-1) option. 

When the amplifier was removed from the USB connection or was turned off, Windows 7 turned to use the original soundcard of the system. So switching between the headphone amplifier and the original soundcard of the PC was not complicated at all.

Behind the PHA-1 is a selector switch for switching between micro USB input, iPod/iPhone/iPad input and analogue audio input.

I tested the PHA-1 on both an iPhone and iPad – one at a time. Using the provided cable, which is essentially a sync cable but is shorter, the connection was a breeze. After connecting the cable and select the iPhone/iPad selector option, the audio signal was sent to the PHA-1 digitally. The volume control on the iPhone or iPad disappeared after the connection was completed. You need to control the volume on the PHA-1 by turning the volume knob at its front. No app is required on the iPad or iPhone.

Sony says the PHA-1 is ideal for using with its MDR series professional headphones. I tested it with Sony MDR-XB900 extra bass headphones and Sony MDR-EX1000 in-ear monitor headphones. I was impressed with the sound quality of both sets.

The PHA-1 reproduced music with clarity on both headphones but the XB900 reproduced much more powerful bass while the EX1000 reproduced clear music and sweet voices with more subtle bass when used with the PHA-1. During the test, I became addicted to using the PHA-1 as my PC’s soundcard and enjoyed listening to rock music for hours. 

The saxophone sounds of the “Sax for Sex – Beautiful Night Vol 1” were rendered beautifully and sweetly, for example. And female voice of the Best Audiophile Voices V were rendered very sweetly.

Sony PHA-1 portable headphone amplifier retails for Bt18,990.

 

 

KEY SPECS

 

Frequency range: 10Hz – 100 kHz (analogue audio input); Distortion: 0.01% or less (1kHz)

Supported impedance: 8 - 600 ohms

Maximum input: 1Vrms (analogue audio input)

Maximum output (when using the built-in lithium-ion rechargeable battery: Approx. 175 mW + 175 mW (8 Ω, 10 % distortion); Approx. 26 mW +26 mW (300 Ω , 10 % distortion)

Audio output: Stereo mini jack (Only a 3-pole stereo mini plug is supported.)

Audio input: Stereo mini jack, Micro-USB (type B), Dedicated connector for iPod/iPhone/iPad

Power source: Built-in lithium-ion rechargeable battery USB power (USB connector from PC to the portable headphone amplifier)

Supported sampling frequencies/bit: Maximum 96kHz/24bit

Compliant OS: Windows 7, Windows Vista, Windows XP, Mac OS X (10.5.8 or later) 

Dimensions (w/h/d, projecting parts are not included): Approx. 67 x 26 x 130 mm

Weight: Approx. 220 g