Oppo HA-1 DAC / Headphone Amplifier Review

As I told you years ago, the headphone industry is growing every day. People and companies became aware of the potential of this market and many important names started to look its way. Oppo is one of them.

Since I’ve heard about their new products I was really interested in hearing/testing them. Luckily I’ve managed to get my hands on a beautiful HA-1 and we have oppodigital.ro to thank for that.

Introduction

First thing that I thought when looking at the unit was that it was a beautiful piece of gear. Everything is well finished and put together into a eye catching design and sturdy build quality.

I even loved the screen which was a pleasure to look at, especially at night.

Looking at the specs, HA-1 is quite impressive, especially in that price range. You can find everything about the product on the product page, but we will go through some important stuff right here.

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Specifications

Discrete Class A Amplifier

A Class A amplifier conducts signal over the entire range of the input signal cycle. The output transistors are biased to operate in their most linear range, and there is no crossover distortion caused by switching the signal between two push-pull devices. The HA-1’s power amplification circuit for the headphones is Class A built with discrete transistors. The discrete design allows us to hand-pick and match the best parts to build the HA-1.

I am a very big fan of Class A amplifiers. I love how they manage to sound natural, relaxed and still have good pace and impact. HA-1 falls in this category and yes, it gets typically class a hot.

Toroidal Power Supply

A toroidal power transformer offers superior power efficiency and much lower exterior magnetic fields over traditional laminated steel core transformers. The HA-1’s toroidal linear power supply provides a very clean and robust power source to the audio components.

Seems that Oppo knows the importance of power in audio and took it quite serious.

Fully Balanced Design

While HA-1 has single ended outputs, the internal analog audio signal path of the HA-1 is fully balanced.

Clean Signal Path

The HA-1 uses an analog potentiometer (the familar volume knob) to control the volume. By avoiding re-digitizing the audio signal for volume adjustment, the HA-1 provides a clean signal path for the audio. At the same time, the convenience of modern digital volume control is not lost – a remote-controlled motor turns the volume knob and a 10-bit analog-to-digital converter samples the signal to display a numeric dB level.

Considering that the signal goes through the potentiometer, you would guess how important it is. It certainly pleases me to see that HA-1 seems to implement it in a responsible way.

ESS Sabre32 Reference DAC

The SABRE32 Reference ES9018 from ESS Technology is the world’s best performing 32-bit audio DAC solution targeted for high-end consumer applications and professional studio equipment.

This is something that I cannot agree with. While I’ve heard very good implementations of this chip, it’s very hard to make it sound natural, analogical. I consider that “best performing audio DAC” to be just marketing. However, Oppo managed to impress me even with its dac section, meaning that they managed to implement the chip quite well.

Stereo Pre-Amplifier with Home Theater Bypass

The HA-1 doubles as a high fidelity stereo pre-amplifier with both RCA and XLR output ports. A special “Home Theater Bypass” mode can be assigned to any input source, making it very easy to integrate the HA-1 as a stereo pre-amplifier into a home theater sound system.

Made for iPod®, iPhone® and iPad®

The HA-1 passes Apple’s “MFi” certification and is compatibile with the latest iPod, iPhone and iPad to be used as the digital audio output accessory of these devices. By tapping directly into the digital audio signal of these devices and converting the audio to analog using the high performance SABRE32 Reference DAC, music from your favorite portable device will sound its best.

Wireless Audio via Bluetooth

The HA-1 supports Bluetooth Advanced Audio Distribution Profile (A2DP) with both the standard and aptX® high quality codec. Simply pair your phone with the HA-1 and set music free wirelessly from your mobile phone.

DAC Performance Specifications

Specification XLR Output RCA Output
Output Level 4.6 ± 0.3 Vrms 2.3 ± 0.3  Vrms
Frequency Response
(Tested with -10 dBFS / 384 kHz)
10 Hz – 170 kHz (+0/-3 dB)
20 Hz – 20 kHz (+0/-0.07 dB)
10 Hz – 170 kHz (+0/-3 dB)
20 Hz – 20 kHz (+0/-0.07 dB)
THD+N at 1 kHz (A Weight, 20 Hz – 20 kHz) < 0.00056% (< -105 dB) < 0.00056% (< -105 dB)
Channel Separation > 105 dB > 105 dB
Signal-to-Noise Ratio
(A Weight, 20 Hz – 20 kHz)
> 115 dB > 113 dB
Dynamic Range
(1 kHz -60 dBFS, A Weight, 20 Hz – 20 kHz)
> 115 dB > 113 dB

Headphone Amplifier Performance Specifications

Specification Condition XLR Input – Balanced Output RCA Input – 6.35 mm Output
Maximum Output Power (Per Channel) Into 600 Ohm 2400 mW 600 mW
Into 32 Ohm 3000 mW 3500 mW
Rated Output Power
(Per Channel)
Into 600 Ohm 800 mW 200 mW
Into 32 Ohm 2000 mW 500 mW
Frequency Response 10 Hz – 200 kHz (+0/-1 dB)
20 Hz – 20 kHz (+0/-0.04 dB)
10 Hz – 200 kHz (+0/-1 dB)
20 Hz – 20 kHz (+0/-0.04 dB)
THD+N at 1k Hz
(A Weight, 20 Hz – 20 kHz)
Rated Power < 0.0018% (< -95 dB) < 0.0056% (< -85 dB)
50 mW < 0.001% (< -100 dB) < 0.0022% (< -93dB)
Channel Separation > 120 dB > 90 dB
Signal-to-Noise Ratio
(A Weight, 20 Hz – 20 kHz)
> 111 dB > 111 dB
Dynamic Range
(1 kHz -60 dB, A Weight, 20 Hz – 20 kHz)
> 120 dB > 115 dB
Output Impedance 0.5 Ohm 0.7 Ohm

Pre-amplifier Performance Specifications

Specification XLR Input – XLR Output RCA Input – RCA Output
Rated Output Level 4.6 Vrms 2.3 Vrms
Frequency Response 10 Hz – 200 kHz (+0/-2 dB)
20 Hz – 20 kHz (+0/-0.04 dB)
10 Hz – 200 kHz (+0/-2 dB)
20 Hz – 20 kHz (+0/-0.04 dB)
THD+N at 1 kHz (A Weight, 20 Hz – 20 kHz) < 0.00056% (< -105 dB) < 0.00071% (< -103 dB)
Channel Separation > 120 dB > 110 dB
Signal-to-Noise Ratio
(A Weight, 20 Hz – 20 kHz)
> 110 dB > 105 dB
Dynamic Range
(1 kHz -60 dB,  A Weight, 20 Hz – 20 kHz)
> 120 dB > 115 dB
Maximum Gain (100 mVrms input) 6 dB 6 dB

Indeed, these specs and features are quite impressive also making it a very versatile unit.

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Let’s see if the sound quality is on par with what we found on paper.

 

Listening Impressions

The tests were performed with Sennheiser HD800,  Hifiman HE-560, Oppo PM-2, Audio GD Master 9, MSB Analog Dac.

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I’ve tested the unit both as amplifier/pre-amplifier and dac separately and it behaved quite nicely in all areas.

Most of the tests below were made as a dac/headphone amplifier combo.

The amplifier managed to easily drive all the headphones in the tests, even the more power hungry HE-560 which was very energetic and well controlled on HA-1.

Rodrigo y Gabriela- “11:11”

This song had lots of energy on the HA-1 showing good impact with strong but fast transients, good details and PRAT. The guitars were fast, detailed and with strong plucks. Overall the song was very enjoying, but I almost thought that I would want a little more depth in the scene and deeper lower notes, but realized  that the amplifier didn’t reach the optimal temperature to work at its best. As any class A amplifier, it needs to warm up in order to work in its parameters.

ACDC – Boogie Man

I’ve enjoyed this song very much on HA-1. It really offered a head banging experience from beginning to the end. The drums were strong with very good impact and energy, the voice was textured, rugged and present, while the guitars vibrated full of energy.

Pink Floyd – Another Brick in the Wall ( Part 2 )

HA-1 is capable of really clean sound indeed.Everything from voices to instruments sounded quite natural and free of digital harshness. While the sound was effortless, this didn’t take out from the song’s energy at all. The voices were clear, present and quite textured. The guitar in the end of the scene was a pleasure to listen to, as it was very extended and it came in a very natural and smooth way. The drums were extended, punchy and present throughout the song, while the instruments and voices played around in a very organized and holographic manner throughout the scene.

Hugh Laurie – Battle of Jericho

I’ve really grown fond of this wonderfully looking unit. Not only that it looks amazing, but it also sounds great. The drums from the beginning of the song were deep and showed a deep soundstage through their reverberation. The guitars were very pleasant to the ears, showing good extension, sparkle, detail and tactility. I also loved Hugh’s voice, as it seemed  natural, extended and detailed. I just loved how all the instruments and voices blended in the scene in a holographic, playful and effortless manner.

Leonard Cohen – Vilanelle For Our Time

Leonard’s voice was quite impressive. HA-1 managed to show his ruggedness in a very accurate and guttural manner. The presence was quite good, and if it would have had a little more body, it would have reached the excellent barrier.

Coldplay – We Never Change

I loved those guitars as they were full of vibration, sparkle, life. The voice came in a transparent / clean manner. The soundstage was quite deep and holographic, creating a very scenic and impressive listening experience.

Infected Mushroom – Mambacore

This was another extremely pleasant surprise. I didn’t expect this bass quality from HA-1, as it showed incredible speed, control, extension and punch. The PRAT was amazing and lead to a really headbanging experience. Besides that, I was really immersed into this weird song by all the details coming from nowhere and from every direction.

Vivaldi – Autumn – Allegro (La Caccia)

If HA-1 makes you headbang on rock, it can make you a conductor on classical music. I was really impressed on this song as well. The instruments presented an abundance of details, very good transients, making you notice every pluck and every chord vibrating. The imaging and instrument separation were excellent as well.

OPPO-HA1 Review

Summary

Bass

The bass was quite impressive, showing excellent depth, control, speed and punch. It wasn’t as deep as on M9 / Analog Dac, but it was very enjoyable and not very far from it.

Midrange

The midrange is rich, detailed and clean. I just loved it from the beginning to end. Every instrument, voice was present, textured, detailed and natural.

Treble

The treble was quite ok, even when using the unit as a whole. I didn’t find digital glares into it. It sounded natural, extended and sparkly. This was a pleasant surprise, considering it has a sabre dac implementation.

Transparency

I found the unit to sound very transparent, being a very clean window to the sound. While not as transparent as M9, it came quite close to it, and M9 is the cleanest amplifier I have ever heard.

Details

This is another area where this unit shines. Every instrument, voice were rich with details leaving the song with lesser mysteries.

Transients

The transients are powerful and fast. I just loved them as they really do have a very strong impact and fast decay. This also leads to a controlled, energetic and tactile sound signature.

Soundstage, Imaging, Instrument Separation

The soundstage was quite big and also holographic. The sounds were flying all around you, showing very good imaging. The instruments were  clearly separated as well. HA-1 handled crowded passages in an effortless manner.

Neutral but Natural Sound

I found HA-1 to be true to the source and to lack coloration. Everything sounded neutral but also quite natural. I don’t remember things to sound off, colored or unnatural.

Effortless

Everything sound comes easily, in an effortless and easy manner. I never heard it struggle. This is a quality of class a and very good amplifiers, and HA-1 falls in this category.

Amplification

While the unit is impressive in all sections, I found the amplification to be even better. HA-1 has one of the most clean / sound signature I’ve heard until now. It’s not quite on Audio GD Master 9 level, but it’s not very far from it, M9 being the cleanest headphone amplifiers I’ve ever heard. Not to mention that it has a natural and effortless sound signature that also has good PRAT, impact and details.

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Conclusions

Oppo made quite a statement with its first dac/amp unit designed for the headphone industry. Considering all the features and the sound quality of the HA-1, I consider this product to be a success.

It became my favorite headphone DAC/AMP combo in this price range. Actually, I don’t think that you can find anything else to have all its features and this sound quality near that price.

If you want a do it all unit for your headphones, or maybe just an excellent headphone amplifier / dac / pre-amp,  you must hear the Oppo HA-1.

 

Pros

  • Excellent build quality and looks
  • Very good whole in one product overall with excellent amplification and very good dac section
  • Excellent fast but controlled and deep bass
  • Clean and rich midrange
  • Extended, clean and sparkly treble
  • Very good details
  • Exploding but effortless transients
  • Very good soundstage and imaging
  • Natural and neutral sound signature
  • Effortless sound
  • Very versatile unit with lots of inputs and features
  • Very good price / performance ratio

Cons

  • Didn’t find anything noticeable