Discrete Class A Amplifier - A Class A amplifier conducts signal over the entire range of the...

Oppo HA-1 Integrated Headphone DAC and Amplifier.

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  • 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.

    Fully Balanced Design – The internal analog audio signal path of the HA-1 is fully balanced. For digital audio, the signal runs in balanced mode all the way from the DAC to the output jacks. Balanced analog input is kept intact, and single-ended input is converted to balanced at the input buffer. All single-ended outputs are derived from the balanced signal as well. The balanced design provides better common-mode noise rejection and improves signal quality. The balanced headphone output provides twice the voltage and four times the power of the single-ended output, enabling the HA-1 to drive the most power hungry headphones. It also provides better channel separation by eliminating the common ground return path.

    Clean Signal Path – The HA-1 uses an analog potentiometer (the familiar 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.
    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.

    ESS Sabre32 Reference DAC – The DAC is one of the most important components for digital audio playback. 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. With the ESS patented 32-bit Hyperstream™ DAC architecture and Time Domain Jitter Eliminator, the SABRE32 Reference DAC delivers an unprecedented DNR (Dynamic Range) of up to 135dB and THD+N (Total Harmonic Distortion plus Noise) of -120dB, the industry’s highest performance level that will satisfy even the most demanding audio enthusiast. To learn more about the technologies behind the exceptional performance of the SABRE DAC, please read the SABRE Technical White Paper.

    Asynchronous USB DAC - By bypassing the low fidelity, poor quality DAC of traditional computer soundcards, the HA-1 turns any computer into a high performance multi-media source by converting digital audio to analog through the ESS Sabre32 Reference DAC. The asynchronous transfer mode uses the high precision clock inside the HA-1 to drive the audio signal, not relying on the clock quality of the computer. HA-1's USB DAC input supports PCM up to 384 kHz 24-bit and DSD up to 12 MHz (DSD256).

    Made for iPod®, iPhone® and iPad® – The HA-1 passes Apple's "MFi" certification and is compatible 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.

    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.

    Trigger Input & Output – The HA-1 features 12V trigger input and output. When used as a stereo pre-amplifier, the trigger output can turn on your power amplifiers automatically when the HA-1 is turned on. You can also turn on the HA-1 automatically by connecting its trigger input to the trigger output of a source device or a surround sound processor.

    Remote Control & App – The HA-1 comes with a remote control that provides volume control, direct source selection and even playback control for digital audio sources. A remote control app is available for both Apple's iPhone and Android-based smartphones. The app works over Bluetooth and offers the same functionality as the physical remote control.

    Adjustable Gain Setting – The headphone power amplifier has an adjustable gain setting. For optimal sound quality and to best match your headphones' sensitivity, you can choose between Normal and High for the Headphone Gain setting.

    Build Quality – The HA-1 is housed in a brushed aluminum chassis. The Class A amplifier naturally consumes more power and generate more heat than other types of amplifiers, so the HA-1 is designed with ample ventilation and built with the finest components to ensure long term stability and performance. Tipping the scale at 13 lbs, the HA-1 is a solidly built desktop headphone amplifier.

Recent User Reviews

  1. MRC001
    "Excellent sound, both headphone and line stage"
    Pros - Sound Quality, Input Variety, Build Quality
    Cons - No headphone xfeed
    Based on solid reviews everywhere, I bought an HA-1 and have been super happy with it.
    I use the unbalanced 1/4" headphone jack to drive Sennheiser HD-580s. I use the balanced headphone jack to drive Audeze LCD-2F. I use the balanced line stage to drive an Adcom 5800 to Magnepan 3.6/R speakers. I use the unbalanced line stage to drive my Tascam digital recorder.
    The headphone balanced output runs in pure class A, beefy powerful, with adjustable gain so it can drive almost any headphone. It gets quite warm. The headphone unbalanced output sounds equally clean, though 6 dB quieter (half the voltage, 1/4 the power). The line stage is as impressive as the headphone output. The HA-1 is neutral (neither bright nor warm) and smooth yet detailed. No euphonics, just incredibly detailed yet natural sound for those who want to hear exactly what's in the source without any editorializing.
    I would have liked to have had a headphone crossfeed circuit like the ones that Meier amps have, but given all the HA-1's other strengths, I can live without that.
    I bought a refurbished unit directly from Oppo. Saved $250 on the price, it looks and runs like new, with same warranty.
    Details http://mclements.net/blogWP/index.php/2015/09/06/review-oppo-ha-1/
  2. Armaegis
    "great features but disappointing sound"
    Pros - build quality, user interface, bluetooth integration
    Cons - bright dac, bright amp
    Micro review of the Oppo HA-1:
    rankings (because the bars to the side for some reason are not representative of the rank I gave)
    audio quality: 2/5
    design: 4/5
    quality: 3.5/5
    value: 2.5/5
    - build quality is great
    - nice pot, motorized, smooth and solid feel
    - user interface is simple and clean, intuitive menu system
    - connectivity is top notch
    - I can easily see this becoming the centrepiece of a system
    - but I couldn't get the usb drivers to work
    - bluetooth from your smartdevice, operate both as a streaming device and as remote: fantastic!
    The dac
    - um, no thanks, it's headache inducing
    - really edgy transients, I could maybe see this being good if you have older ears or mild hearing loss, but for younger ears this will be very fatiguing
    - otherwise good definition
    - chain: fed coax from a NuPrime uDSD and coax/optical from a Peachtree X1
    The amp
    - can't handle the HE-6; at full power into the headphone jack the HA-1 shuts down (likely a safety, it happened twice, I'm not going to push that further)
    - but otherwise seems ok
    - good energy
    - I think it sounds better in low gain, even if perhaps lacking a tiny bit of dynamics
    - but bright sounding, somewhat "pushy" in the upper mids
    - especially guitar picks
    - if using the dac, this combo is especially bright
    The preamp
    - clean and functional, has a bit of gain to it so not a direct pass through (not affected by the headphone gain selection)
    - also slightly bright, less so than the amp section, but similar characteristic
    - This would be good with darker cans like the Audeze LCD-2/3 or the Oppo PM-1/2 or Sennheiser HD600/650, but it's a terrible match with the HE-6.
    - Preamp output still retains that bright characteristic, even when using analog inputs.
    - For the price as an all-in-one unit, it really comes down to how the dac sounds for you. I have some friends who really love the sound, but for me it doesn't work. Feature-wise, the HA-1 hits all the right checkmarks.
    grizzlybeast likes this.
  3. Currawong
    "Oppo's HA-1 is a very flexible headphone amp and home theatre DAC/pre-amp and about spot-on for the money."
    Pros - No lack of inputs, including Bluetooth; Headphone amp is good all-round with plenty of power; Functionality is well thought-out.
    Cons - Mute function for the pre-amp output only accessible on the remote. Knob feel for the volume is terrible. Display text is hard to read at a distance.
    Thanks to Oppo Digital Japan for allowing us to borrow the PM-1 and HA-1.
    Oppo coming out with a pair of headphones was quite a surprised, especially a pair of planars. Likewise the HA-1, though it is logical that a company would provide an appropriate matching amp to do with their own headphones. 
    The HA-1 is based upon the BD-105 essentially, but with fewer features and a better headphone amp, in this case with balanced output. Like the BD-105, apart from the lack of disc playback, it is still designed to be the centrepiece of your home theatre system with no less than 8 inputs: RCA and XLR (balanced) analogue and S/PDIF, optical, AES and Bluetooth digital. The latter supports APTX transmission which gives essentially CD quality wireless audio transmission. For iDevice users there's even a special USB port on the front for when a friend brings around their music on their phone or iPod.
    Selecting the inputs is thankfully very simple, each has its own button on the included remote control. They can also be selected simply by turning the selector knob on the front panel until the desired one is highlighted.
    By pressing the selector switch instead you cycle through the options for the unit:
    Display type, which includes a funky digital rendition of analogue style meters and an EQ display or just information on the input used and music playing.
    Home Theatre Bypass, which is a fancy way of saying that the volume control for the pre-amp output can be switched to a fixed line-level instead.
    Headphone amp gain.
    My only complaints about the unit are here in that the text on all the displays was too small to be read at any kind of distance. Also, the volume knob has the worst "knob feel" of any I've ever encountered. One other issue is that the pre-amp output "mute" function can only be switched using the remote, so if you can't find the remote but only want to listen through headphones, you'll have to switch off the rest of your system or un-plug it. Also, though people are unlikely to encounter it: Make sure to switch the unit off via its own power control. When I used my Power Plant Premier to switch everything off, the Home Theatre Bypass reset itself to "fixed" mode and the next time I played music I got blasted!


    Now I've had the chance to try the HA-1 in a few scenarios, such as a HP amp and pre-amp with the in-built DAC and external DACs, here are my thoughts. Note that I listen to an incredible variety of music, too long to list here.

    The HA-1 is about spot-on for value. It isn't the most resolving DAC or amp compared to, say, my Master 7 or Hugo. I was talking to anakchan about it and the word he used was "polite" which I tend to agree with. I've had mixed results with ES9018-based DACs and the HA-1 is one of the better ones, not having the flatness to the sound poorer implementations have that usually annoys me with acoustic instruments. The headphone amp gives an equally effortless-sounding presentation with both Oppo's own PM-1s and the Audeze LCD-XC as well as the Sennheiser HD-800, suggesting good power delivery. If I hadn't owned my main DACs, I'd be quite happy with the HA-1 sonically, as it does a good job of getting out of the way of the music and presenting it as it is. If anything though, I felt the HA-1 was too polite for the PM-1s and they sounded better directly out of the Hugo! It was a nicer match with the brighter HD-800s.
    Comparing it to other equipment to get a handle on its actual ability to resolve detail, if I used the HA-1 as a DAC, it wasn't quite as resolving as my Master 7 or the Chord Hugo, missing out on some micro-detail. Likewise if I used the HA-1 as a headphone amp for my Master 7 or the Hugo, knowing that both are more resolving than the Oppo's built-in DAC, the greater resolution of either unit didn't come through the amp. Both units, however, are far more expensive than the the Oppo, the Hugo being 2.5x the price, so if anything the Oppo did well.
    I also tried the HA-1 using the Bluetooth input using my iMac, and the results were very good, only a tiny bit behind the sound quality of a direct connection, something only apparent when directly compared.
    Overall though I felt performance was spot-on for what Oppo are asking, especially considering the wealth of features included. It would best suit someone who wants to use the variety of features, such as with a pair of active speakers as well as headphones. With a pair of, say, the inexpensive but good quality Emotiva active speakers and headphones of choice it would make a great complete rig. 

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