Oppo HA-1 Impressions Thread

Discussion in 'Headphone Amps (full-size)' started by aamefford, May 7, 2014.

  1. Hooster
    If all you need is what the Deckard offers, then I would buy a Deckard. The HA-1 would be overkill because it has so many features that you would not be using.
     
  2. Here2rock
    My only concern is the balanced outpout, Deckard does not have it, does it make a big difference or a feature which I many not use?
     
  3. swmtnbiker
    Depends on the headphone, but the HA-1 balanced out is superb and has enough power to drive *anything* well. With the HD 650, HD 660S, and AEON Flow Open, the difference between the balanced and single-ended outputs is not subtle at all. Balanced is where it's at.
     
  4. MRC001
    Balanced is a superior engineering design; properly implemented, it improves S/N by 6 dB. And balanced cables are more immune to external noise. But the S/N of well-engineered unbalanced is already so high (can be well over 100 dB) that balanced may not offer any practical audible benefit.
    Balanced is nice to have all else equal, but I wouldn't make a buy-no buy decision based on it.

    PS for perspective, the primary use of balanced is for microphones, where a very small (millivolts) signal is carried over long wires. You need all the noise rejection you can get. Line level audio signals are roughly 1,000 times or 60 dB stronger than a typical microphone and the cable runs are much shorter, so they are less prone to noise, and less need for balanced.
     
    Last edited: Nov 9, 2017
    Hooster likes this.
  5. Hooster
    It does make a difference, but only if you use it :)
    I actually re-cabled a pair of AKG Q701 headphones for balanced operation, just so I could use the balanced output. The sound was better, but I never really got along with the Q701s...
     
  6. Here2rock
    After hearing all the experts' opinions, I am just getting a little confused. When I auditioned the HA-1 a while back, I could hear the difference between a balanced and single ended output. It seems to be very well implemented on the HA-1.

    Now to confuse myself a bit more, how does HA-1 stacks up against NFB-28.38? It does have a newer DAC chip ES9038 v ES9028 on HA-1, is it all just numbers or is there a benefit from the newer DAC chip? How well is it implemented on NFB-28.38?
     
  7. polecrab
    Here2rock and Hooster like this.
  8. MRC001
    The HA-1 doesn't output the same level to balanced and unbalanced outputs. If you switch back and forth to compare, you must have a way to ensure the levels match. Doing this by ear is unreliable because small differences in volume (a fraction of a dB) are psychoacoustically perceived not as volume, but as differences like richness or timbre. The only way to level match reliably is to measure levels with equipment. Thus even if the balanced and unbalanced outputs of the HA-1 (or any other amp) were identical, people auditioning them would find they sound different because the levels would never perfectly match. This is not a dig on any listener's experience, skill or caution; it's just a biological fact of how our ears & brain work.

    That said, I like balanced outputs; it's the best/right way to deliver the signal. And the HA-1 in particular implements it well. But put it in the proper perspective. It adds complexity, it's not always implemented properly, and even when it is, it doesn't always make any audible improvement.

    PS I like the article posted above. Well put, and essentially what I've been trying to say. Though I disagree a bit with Benchmark in that they imply that the additional complexity always overwhelms the advantages, which I would dispute. I believe balanced, when properly implemented, is superior engineering. But everything else they said is spot-on correct.
     
    Last edited: Nov 9, 2017
  9. Here2rock
    You are right, it must have been the extra output through balanced output making me think that it was driving the headphones a bit more effortlessly without really pushing the volume knob all the way down. If I was to draw an analogy then is it correct to think of a balanced output V single ended output to a car with V8 car engine V a V6 engine?
     
    Last edited: Nov 9, 2017
  10. MRC001
    Unfortunately, there's no good analogy to car engines.

    With unbalanced, the - wire is ground. It never carries a voltage. The + wire carries the musical signal; its voltage will vary up and down relative to ground. This is why it's sometimes called "single ended": only one wire carries the musical signal.

    With balanced, both + and - carry the musical signal. Neither is ground; that is a separate wire. The + and - are always exact opposites of each other, mirror images across 0 V. If at some snapshot in time one is +0.7 V, then the other is -0.7 V. Because of this, the pair always sums to zero volts, which makes the overall wire (the pair or them) immune from noise or interference; it has net zero electrical field. Also, it carries twice the signal level as unbalanced of the same voltage, because being opposites, the difference between them is twice as much. That is why it has 6 dB better S/N: a voltage ratio of 2:1 is 6 dB.

    A speaker or headphone responds to the relative voltage difference between the wires. It doesn't know or care if one wire is always ground. So you don't need to modify headphones or speakers for balanced signals.
     
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  11. Here2rock
    Thank you for your very technical answer.
     
  12. youngarthur
    Many thanks, this is the first time I have really understood the difference between balanced/unbalanced.
     
  13. Bangkokphoto
    Has anyone experimented with the XMOS controller in the HA-1? The Oppo uses the XMOS 6U6C5 to control the display... I was wondering if it would be possible to have a custom spectrum render on the LED.
     

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