Oppo's best known for its Blu-ray players, but earlier this year it introduced a high-end headphone, the PM-1. Not long after that Oppo put the word out that a combined headphone amplifier/digital converter was about to be released. It's called the HA-1, and when it arrived on my doorstep it wasn't what I expected.
I thought it would look similar to Oppo's Blu-ray players, but it's completely different and considerably more elegant than that. My review sample's gleaming aluminum chassis is beautifully finished, the design hearkens back to the days of 1980s Japanese flagship receivers. Build quality is on par with today's high-end gear that sells for two or three times the HA-1's price. It's also available in black; the 13-pound (5.9 kg) component measures 10 x 4.8 x 12.2 inches (254 x 80 x 333 mm).
The analog audio section of the HA-1 is a fully balanced, Class A design, you can use the built-in high-resolution 192kHz/24 bit or DSD digital converter, or if you prefer, hookup an external converter.
Connectivity options are extensive, you get an optical (Toslink), coax (RCA), XLR, Bluetooth, and computer USB digital inputs, plus a separate USB connector for iPhones, iPods, and iPads. There's also one set each of RCA and XLR analog inputs and outputs, so you can use the HA-1 as a stereo preamp in a hi-fi system. I tried it that way, with my Oppo BDP 105 Blu-ray player, First Watt J2 power amp and Zu Druid V speakers. Sound quality was first rate, the HA-1 is worthy of use with systems of this caliber. Or, you can use a pair of "active" powered speakers; the HA-1 comes with a slim, all-metal remote control.
The HA-1's front panel's large display can be set up to show either status (input selected, audio format, gain, etc.), digital VU meters, or a spectrum display of the frequencies being played. There's a standard 6.3mm headphone jack and a four-pin XLR "balanced" jack for use with some high-end headphones. Naturally enough, Oppo's PM-1 headphones can be used with the XLR connector, so can Audeze, HiFiMan, and some Sennheiser headphones.
The HA-1 coaxed the best sound I've ever heard at home with my Abyss AB-1266 headphones, which are far and away the best headphones I own, but I spent a lot of time with Oppo's PM-1 headphones plugged into the HA-1. There was clear synergy to the pairing, but my newly revised Audeze LCD 2 & LCD 3, AKG K812, and HiFiMan HE-560 headphones were also auditioned with the HA-1. The takeaway impression was consistently one of clarity and power.
When I compared the HA-1 with my Burson HA 160 headphone amp while listening through my Audeze LCD 3 and HiFiMan HE 560 headphones, the HA-1's ability to reveal more low-level detailing was immediately apparent. I could hear more of my recordings' reverberation and ambience. The "spaces" between instruments in a stereo image were deeper, so the sound had a more three-dimensional presence. The HA-1 also sounded amazing with my Sennheiser iE800 in-ear headphones.
The HA 1's effortless transparency outpaces the Burson HA 160's, which sounds brighter, but less detailed. The HA-1 sounds more "natural"; the HA 160 adds a slight electronic "edge" to the sound. Curiously, with the Oppo PM-1 headphones the differences between the two headphone amps were smaller.