Oppo HA-1 Headphone Amp and PM-2 Planar Magnetic Headphone Review


Headphone TypePlanar Magnetic
Sensitivity102 dB @ 1mW
Nominal Impedance32 Ohm
Review DateDecember 1, 2014
PriceCheck on Amazon

When Oppo is mentioned, most Hi-Fi aficionados think of reference quality Blu-ray players. Now they can add headphones and headphone amps to that list. Oppo is taking a serious interest in the lucrative headphone market, and I don’t mean a run-of-the-mill Beats clone. Oppo has high-end personal audio in mind with the new HA-1 Headphone Amp + DAC and the PM-2 Planar Magnetic Headphone. The HA-1 has been available for several months, but the PM-2 is a new release. The PM-2 is a more affordable version of the earlier released Oppo PM-1.

They share the same internals that produce the sound and only vary in material finish and included accessories. At $699, The PM-2 is not a low end headphone, but is a low priced planar magnetic headphone. Oppo has the planar magnetic $995 Audeze LCD-2 and $900 HIFIMan HE-560 beat in price with only the $500 HIFIMan HE-400i costing less than the PM-2. The Oppo HA-1 is a hefty amp, capable of powering any of the popular power hungry planar magnetic designs including the $1,300 HIFIMan HE-6. This headphone amp and its ESS ES9018 DAC will happily sit in a reference personal audio system as the anchor.

Quality Fit and Finish – Inside and Out

Headphone Type:Planar Magnetic
Sensitivity:102 dB @ 1mW
Nominal Impedance:32 Ohm
Review Date:December 1, 2014
Price:Check on Amazon
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At 10.0″ x 3.1″ x 13.1″, the Oppo HA-1 is not the smallest headphone amp on the market but it is extremely well built. Constructed with brushed aluminum and weighing 13 lbs, the build quality of the Oppo HA-1 is off the charts. The body is available in either a silver or black finish. The top plate of the HA-1 has a vent for the heat generated from its Class-A amplifier design. The reason for all that heat? The ability to drive all the popular power hungry headphone designs like the HIFIMan HE-6 and Audeze LCD-3. With a 600 Ohm load, the HA-1 can push out 2400 mW via the XLR balanced output and 3000 mW into 32 Ohm. The Oppo HA-1 is a fully balanced design, from DAC to output, and even single ended input is converted to balanced at the input buffer. The balanced headphone output provides twice the voltage and four times the power of the single-ended output. This means using a balanced cable with the Oppo PM-2 provides more headroom and better dynamics. I found the balanced output to offer the best performance for the Audeze LCD-3 and HIFIMan HE-6.

HA-1 Inputs and Outputs

HA-1 Inputs and Outputs

The Oppo HA-1 uses an analog potentiometer for volume control and a motor provides remote control of the volume setting. This volume control design is expensive and harder to manufacturer, but is the most audibly transparent volume control method available. To best match the range of headphone sensitivities, the Oppo HA-1 includes a gain setting of Normal and High. Supplying clean and robust power is a toroidal linear power supply.

The heart of the Oppo HA-1 DAC is an ESS Sabre32 Reference ES9018, currently the best consumer digital to analog converter. With an astounding dynamic range up to 135dB and a THD+N of -120dB, you really can’t ask for anything better than that. Asynchronous USB utilizes the XMOS USB chip for processing PCM up to 384 kHz 24-bit and DSD up to 12 MHz (DSD256). The Oppo HA-1 even has Apple MFi certification to allow it to read digital audio directly from iProducts. Also included is an external Bluetooth antenna for audio streaming utilizing the higher quality, but still compressed, aptX codec.

The Oppo HA-1 has a home theater bypass mode allowing it to function as a two channel stereo pre-amplifier in a home theater setup. To further its ability as a pre-amplifier, Oppo has 12V triggers for input and output. These triggers allow the Oppo to turn on power amplifiers or be turned on by another device like a surround processor.

Control of the Oppo HA-1 is accomplished either by the front panel knobs, included remote control, or an iPhone or Android phone via Bluetooth. The front panel uses a 4.3” color display that shows input source options, audio spectrum, voltage meter, and current level when adjusting volume.

The Oppo PM-2 Planar Magnetic headphones are a new, more