Headphone Amplifier HA-1 (price: 1 498,00 €, VAT excluded)



James Soanes

Oppo Digital UK, Technical Officer


DP: Why did a successful Blu-ray maker move into headphones? JS: Headphones are a very buoyant market sector and was the obvious opportunity for diversification of our product portfolio. Crucially, we did not want to create another ‘me too’ range of headphones. With the technology, design and attention to detail of the PM-1, we felt we could make a big impact.


Why did you opt to make a headphone amp when there are so many good ones around?

We wanted to create a fully functional amplifier that could be used across a wide range of sources and with the latest DACs inside for the best performance. Once we started to develop the idea, we felt that we had something really special and, while the PM-1s work really well with whatever amplifier you use, the HA-1 shows them off to their true potential especially when they’re run using the balanced cable.


What’s special about the PM-1’s technology and design?


The obvious technology is the use of planar magnetic drivers, which we have developed to offer a very honest reproduction of the original signal across a very wide frequency bandwidth. Unusually for planar magnetic drivers, we have managed to get a significantly higher efficiency, allowing for greater sensitivity, meaning that users can use the PM-1 with mobile devices – a first for this type of headphone. Comfort was a major factor too. Industrial design was also key, which when combined with the high–quality materials such as polished steel and lambskin lambskin leather, makes for a product that looks as good as it sounds and that owners will be proud of and want to use and enjoy.




Origin USA/China

Type Class A headphone amplifier/preamp/ DAC

Weight 5.9kg

Dimensions (WxHxD) 254 x 80 x 333mm

FEATURES Coaxial, Toslink; USB; AES/EBU and Bluetooth digital inputs Support for PCM; DSD (DoP v1.1 or native); MP3; AAC 32-bit/384kHz ESS Sabre 9018 DAC 4.3in fine-pitch colour display


Who would have thought it? Obscure manufacturer of decent Chinese optical disc players starts spin-offcompany (Oppo Digital Inc.) in

California to make high-quality hi-fi products. It’s not a typical tale of hi-fi success, but the story is getting ever more believable with every product launch. Less than a year after the excellent PM-1 headphones were released, the company now has its own matching DAC/preamp/

headphone amp too – in the rather pleasing shape of the HA-1.

Some readers may be familiar with the BDP-95EU (HFC 347) and BDP-105D Blu-ray players. Ten years ago the likes of Sony and Pioneer

were championing high-end optical disc spinners, but now that honour falls to Oppo, whose two most recent generations of BD players have been excellent. The HA-1 duly borrows a good deal of circuitry from the BDP-105D including the ESS 9018 Sabre32 DAC and digital filter chip. Although touted as a “high performance headphone amplifier”, it actually doubles as a USB DAC, stereo preamp with Bluetooth streaming. In short, it’s packed with facilities. The idea behind the HA-1 then, is to provide a multi-functional digital hub (that also has an analogue input) with an excellent headphone driver stage built in, at a price that’s still keen. My time with it suggests that the company has succeeded. Together with the unbalanced analogue input via RCA phono sockets and the balanced XLR audio input, you get coaxial and optical digital inputs, plus an AES/EBU balanced digital input via XLR and an asynchronous USB type-B input. Via this, instead of ‘just’

24/192 you can play out 32-bit, 384kHz files, so the Oppo will handle the increasingly popular DXD (24/352.8) format without downsampling. There’s also DoP (DSD over PCM), which runs at up to DSD at four times its normal data rate (DSD256 at 11.2896MHz/1-bit in ‘native’ mode). In short, this product covers a vast range of bases and I know of nothing else on the market that has the same combination of facilities and functionality at its price. Considering its sub-£1,100 price, that huge range of connectivity options and its tremendous format compatibility, you’d hardly call the Oppo expensive. You could easily lavish £300 on a headphone amp, another £300 on a passive preamp, and a further £500 on a DAC and you’d still struggle to match what the HA-1 provides. Yet the unit is built extremely well both inside and out. Everything gets juice from the generously specified main toroidal power transformer; from this linear power regulators and filters follow with custom-made capacitors. The half-width casework is all aluminium and of very high quality at the price. It sports a large rotary volume control on the right (via a motorised potentiometer) and a smaller rotary source selector on the left; centre stage is the 4.3in hi-res colour screen. As well as displaying source selection, settings and volume, it also has a choice of display modes from classic VU meters (for seventies hi-fi children), a bar graph spectrum display (for eighties kids) or an information summary (for nineties squares)! There’s even a smartphone app, should you not wish to use the supplied remote control. Overall finish is superb, again justifying its price premium over the Audiolab M-DAC. One remark that has to be made, though, is that the Oppo runs very hot indeed, so remember not to

put anything on it.


Sound quality

To those who have not yet heard the Oppo PM-1 planar magnetic headphones, you’re in for a treat! These are one of the most clear, open

and detailed sounding headphones at anywhere near their not inconsiderable price (see p44). The problem is that they aren’t the world’s

most beguiling things to listen to; they have an unerringly forensic nature that sets out to tell you allabout the recording and indeed the

source you’re using to reproduce it, warts and all. Given that most people’s front ends are less than ideal, you can sometimes come away with

the feeling that the PM-1s need a little more warmth. Well, unsurprisingly, the HA-1 gives just this – you’d never call it euphonic, but it’s a generally neutral sounding device that leans ever so slightly to the warm side – especially in the low and mid bass

region – and is an excellent match for the Oppo headphones. I first audition the HA-1 as an analogue preamplifier via its RCA line inputs, where I find it offers plenty of detail and insight, with a smooth, sophisticated and fairly neutral sound quality considering its price point.

Sonically via line in you can do rather better with several all-analogue preamps at this price – the Oppo can sound a little mechanical and opaque by comparison – but then again, the HA-1 packs vastly more functionality in for the money, so it’s not strictly a fair comparison.

When you switch in the DAC section, things begin to hot up. Fed by Cyrus CD Xt Signature transport via its coaxial in, the Oppo impresses.

808 State’s Pacific State comes over with a surprising degree of bass weight, and oodles of detail. It’s easy to hear that trademark ESS Sabre

sound; you get a high precision render of the recording, with its many dense layers. It’s an explicit rather than a romantic sound, and gives a

seat-of-the-pants listening experience. Added to this is that solid bass, which punches things along. Certainly compared with my reference Chord Electronics Hugo DAC, there is more thump to the bass drums and Moog bass synthesiser work. Moving from using the HA-1 as a hi-fi preamplifier driving a power amp, to using it as a headphone amplifier, and this suddenly makes sense. Plugging the PM-1 headphones in shows how well suited the unit is to the task of driving them. While they are both strong taken separately, together the combination easily surpasses the performance of the two individual component parts. They make a very nice noise with Malcolm McLaren’s Waltz Darling – this classic eighties Trevor Horn production opens up and becomes a captivating oppo ha-1 Headphone amp/DA C £1,199


It offers plenty of detail and insight, with a smooth, sophisticated sound



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