Overview: The Sony PHA-2 is a battery-powered portable DAC (digital-to-analog
converter) and headphone amplifier that lets you listen to high-resolution audio
through your headphones. You can connect a PC, an iPod/iPhone/iPad, or a high-res
capable Walkman to the unit using one of the three USB inputs. It will also work
with analog devices as well.
Internal Components and Construction: The PHA-2's PCM1795 DAC samples PCM audio at
192kHz/24-bit, and DSD audio at 2.8/5.6MHz. The LME49860 operational amp
delivers outstanding audio performance with virtually no distortion or noise.
The TPA6120 headphone amp provides a wide 120dB dynamic range to make sure you
can hear every detail in the music. On the outside, the unit features a compact
brushed aluminum enclosure to protect the inside circuitry and components.
Aluminum alloy "bumpers" on the ends provide further protection of the
connecting cables and volume knob from hard impacts.
USB 2.0 Clock: The DAC is equipped with an asynchronous USB 2.0 clock
signal generator that reduces timing inaccuracies when converting digital
signals into analog waveforms. This results in a highly accurate DA conversion
and jitter-free audio for superior audio reproduction that is as close to the
original recording as possible.
Digital/Analog Connections: The PHA-2 has three USB digital inputs: a
Micro USB port for PC and charging, a Type A USB for connecting an
iPod/iPad/iPhone, and a Mini-B USB with an extra pin for connecting a High-Res
supported Sony Walkman. The front panel features two stereo 3.5mm jacks--a
headphone output and a Line Out, which doubles as an analog stereo input.
Note: The 3.5mm inputs only support 3-pole stereo miniplugs. Other
plugs, including 2-pole and 4-pole stereo miniplugs are not supported.
Controls: The front-mounted large power/volume control knob with
plenty of headroom to let you set the volume just where you want it. A
2-position gain switch (normal/high) on the side lets you match the headphone
amp to various headphone impedances from 8 to 600 Ohms. Another 2-way switch is
provided for selecting the output--headphones or the line output. On the back,
there's a 4-way slide switch for selecting between the three USB inputs and the
Lithium-ion Rechargeable Battery: The PHA-2 is powered by a built-in
3.7-volt Lithium-ion rechargeable battery. The battery charges in approximately
7 hours via USB when connected to a PC. With the optional AC-UD20 USB AC
adapter, charging time is only 3.5 hours. Battery life is approximately 17 hours
with an analog input connection and 6.5 hours with a digital input connection.
Compatible Devices: The Sony PHA-2 is compatible with a wide variety
of devices. With three USB inputs and an analog input, it can connect to most
computers and portable audio devices:
- Computer: The unit can play digital audio files stored on your
computer. The unit includes a Micro USB cable for connecting it to your
computer's USB Type A port. The PHA-2 is compatible with the following
Operating Systems: Windows 8, Windows 7 (SP1), Windows Vista (SP2), and Mac
OS X 10.6.8 or later. Note: For Windows PCs, you must first install the driver software "Sony
Portable Headphone Amplifier USB Audio 2.0 Driver" before connecting the
PHA-2. Playing high-resolution audio files on your computer may require you
to download and install "Hi-Res Audio Player" software to your computer.
- Apple Devices: The PHA-2 is compatible with iPhone, iPad, and iPod.
The Type A USB input is provided for connecting the i-device using the USB cable
provided with the device. The digital audio data from the device is transferred
directly to the DAC, and bypasses the device's internal DAC. Compatible models
- iPhone: 5S, 5C, 5, 4S, 4, 3GS
- iPad: 4th gen, 3rd gen, mini, iPad 2, iPad
- touch: 5th gen, 4th gen, 3rd gen, 2nd gen
- classic: 120GB, 160GB
- nano: 7th gen, 6th gen, 5th gen, 4th gen, 3rd gen
- Sony Walkman: The PHA-2 is compatible with high-resolution supported
Sony Walkman devices, such as the NWZ-F880 series. The portable DAC/headphone
amp comes with a USB cable that has a connector that plugs into the Walkman's
proprietary output port. The DAC has a dedicated USB port with an extra pin that
accommodates the Walkman cable. Like the Apple devices, the digital audio data
bypasses the Walkman's internal DAC and is sent directly to the PHA-2's
- Other Devices: The PHA-2 lets you listen to music on other audio
devices, such as a smartphone or portable music player, through the analog
Silicone Belts: The PHA-2 is designed to allow you to
conveniently attach your portable device to the top. Two rubber rails,
approximately 1-3/4" apart, let you rest your player on the top and secure it
with two of the provided silicone belts. The belts lock in place in two grooves
that run along the sides of the portable DAC. If your player is not wide enough
to rest on the rails, a silicone rubber protection mat is provided to prevent
- Frequency Range: 10 Hz - 100 kHz (Audio In input)
- Distortion: 0.01% or less (1 kHz)
- Supported Impedance: 8Ω - 600Ω
- Maximum Input: 1 Vrms (Audio in)
- Maximum Output (with built-in battery):
- 165 mW + 165 mW (8Ω, 10% distortion)
- 90 mW + 90 mW (32Ω, 1% distortion)
- 25 mW + 25 mW (300Ω, 10% distortion)
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