Oppo HA-1 Impressions Thread
Nov 9, 2017 at 8:00 PM Post #5,133 of 5,414
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.
 
Nov 9, 2017 at 8:58 PM Post #5,134 of 5,414
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?
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.
 
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Nov 9, 2017 at 9:10 PM Post #5,135 of 5,414
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?

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...
 
Nov 9, 2017 at 9:21 PM Post #5,136 of 5,414
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?
 
Nov 9, 2017 at 9:31 PM Post #5,137 of 5,414
Nov 9, 2017 at 9:31 PM Post #5,138 of 5,414
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.
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.
 
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Nov 9, 2017 at 10:02 PM Post #5,139 of 5,414
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.

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?
 
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Nov 9, 2017 at 10:19 PM Post #5,140 of 5,414
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 balance output V single ended output to a car with V8 car engine V a V6 engine?
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.
 
Jan 9, 2018 at 5:06 AM Post #5,144 of 5,414
I’ve owned the PM-1 for three years and have recently completed an (expensive) exercise of researching higher-priced options including Utopia, LCD-4, SR-009. I may not have used the best amps with each of them but I believe I have heard enough to assess their overall signatures.
Anyway, while each has some areas of excellence (IMO), I have found nothing as satisfying as my trusty PM-1s. I have just added an HA-1, purchased from Oppo Digital UK, which they classed as B-stock, although to me it’s as new.
Wow. I am so happy with this setup. Very musical, intimate and involving. I think this is where I stop. I’m using Hugo 2 into the HA-1 and Moon Silver Dragon headphone cable (single-ended at the moment). While I’ve wasted money during this journey and now have some expensive items to part with, overall I think it was worth it. For me at least, this may be end-game for desktop use. It’s nice to no longer be constantly planning what to try next.
Very impressed with Oppo gear. It’s superbly designed and built (unlike some other manufacturers!).
Tony
 
Jan 9, 2018 at 7:06 AM Post #5,145 of 5,414
@tonyl59, agree with you, at one point I was going to sell HA-1 but I can't, I really love this amp/dac, very neutral.
 

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