Thanks guys, deep an precise reports, I can imagine the current sound impressions but I think the units needs at least 50 hours to properly break-in. Will follow intensly.
Thanks Lazy Cat. I am curious what Coris has to say after some time. I have been letting it cook with music constantly....listening daily.
The soundstage really has "clicked"... multi dimensional and solid. Granted these are headphone experiences for me only. I may take it to my main system to see how it does through the mains eventually on Sim Audio Amp and Pre amp and Magenpan 3.6R (some mods by me). But through headphones it is stunning now. The unique characteristics are as follows: Resolution has increased to a point that is greater than before, which is very high. But more stunningly, the microdynamics have come to life...music breaths .....is very compelling to listen to. I was hoping for that certain "Class A glow" to the sound that I have had in my past amps. Originally it was not there. But now.....it is.....music has a consistent detailed body/texture that provides for a solid soundstage of ambiance and space. Besides the microdynamics are the effortless dynamics..... the amp just wants to sing and effortlessly erupts with loud/soft dynamics -- almost startling. Of the entire frequency range...everything is quite good....but bass is especially powerful and detailed. Combined with certain dynamic passages that contain lots of low-frequency detail, sound can be quite startling. It is a keeper and Oppo has created a piece of great beauty and value (even for Norway $$ I bet).
Good listening!
I`m not the adept of the burn in theory for electronic circuits/devices. I still have the opinion that an electronic device it have to function on its parameters, from the moment is turned on, if it were designed, assembled and set it up right.
But when about this HA-1 I have no other choice than just agree that it sounds better after heaving it on for a number of hours...
The sound stage become better indeed. So I can confirm what jt25741 observed.
I have also noticed something which it surprised me.
There is written in HA_1 manual that one can use a so called Bypass option to connect directly the DAC output to the further/external pre-amplifier/amplifier. The volume control is bypassed and one get full volume with this option on, and that because one have to be carefully to lower the amplifier volume to not over boost the output level.
I have tried this option. My result: disappointed. In my case it just happened opposite. Switched it on this bypass I have loosed few dB, the sound got quite flat, and the nice bass was gone..
Got back to the Standard, and everything was all right. Rich sound and fine sound stage. What is going on actually? Not very sure... It may be my amplifier?
I suspect the follow: Bypassing the "volume control" in HA-1, one actually bypass the Class A pre-amplifier, which it amplify a little bit the signal, and at least it give this excellent sound out of the device. It may happen that the DAC signal in such bypass position, is outputted through AC separation caps, or something. While the Class A amplifier is coupled in other way to the DAC output. I think the Class A amplifier it act as a buffer for the DAC and its post processing circuitry... Such configuration it may match better with my amplifier? I do not know so far how Oppo made the final stage after the DAC`s I/V, and how the relays inside make the connections.
In my case i have to be carefully when I switch from "Bypass" to Standard, because the output level increase quite much (connected in line the pre-amplifier final stage). BTW, I have (tested) connected the headphone output (load 600 ohm) to my amplifier. Very nice sound!
The DAC bypassed output is specified better by Oppo than the pre-amplifier/headphone output (unbalanced). I was surprised to find out that even though the figures, it sound worse in Bypass setup, than in Standard.
Maybe someone else can come with more informations about this aspect...
But when about this HA-1 I have no other choice than just agree that it sounds better after heaving it on for a number of hours...
The sound stage become better indeed. So I can confirm what jt25741 observed.
I have also noticed something which it surprised me.
There is written in HA_1 manual that one can use a so called Bypass option to connect directly the DAC output to the further/external pre-amplifier/amplifier. The volume control is bypassed and one get full volume with this option on, and that because one have to be carefully to lower the amplifier volume to not over boost the output level.
I have tried this option. My result: disappointed. In my case it just happened opposite. Switched it on this bypass I have loosed few dB, the sound got quite flat, and the nice bass was gone..
Got back to the Standard, and everything was all right. Rich sound and fine sound stage. What is going on actually? Not very sure... It may be my amplifier?
I suspect the follow: Bypassing the "volume control" in HA-1, one actually bypass the Class A pre-amplifier, which it amplify a little bit the signal, and at least it give this excellent sound out of the device. It may happen that the DAC signal in such bypass position, is outputted through AC separation caps, or something. While the Class A amplifier is coupled in other way to the DAC output. I think the Class A amplifier it act as a buffer for the DAC and its post processing circuitry... Such configuration it may match better with my amplifier? I do not know so far how Oppo made the final stage after the DAC`s I/V, and how the relays inside make the connections.
In my case i have to be carefully when I switch from "Bypass" to Standard, because the output level increase quite much (connected in line the pre-amplifier final stage). BTW, I have (tested) connected the headphone output (load 600 ohm) to my amplifier. Very nice sound!
The DAC bypassed output is specified better by Oppo than the pre-amplifier/headphone output (unbalanced). I was surprised to find out that even though the figures, it sound worse in Bypass setup, than in Standard.
Maybe someone else can come with more informations about this aspect...
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Regarding burn in for electronic devices:
Certainly, electrolytic capacitors are known to "form" over tens of hours after application of voltage. Also, the temperature of your device will rise and come to equilibrium slowly. These factors are pretty well understood. Often a new piece of equipment will put out a certain smell for a number of hours until various chemicals evaporate from the newly fabricated device. So it is true that some changes can occur in the first days of use.
Also, I would be interested in the comparison of this device to competitive products such as external DACs.
Certainly, electrolytic capacitors are known to "form" over tens of hours after application of voltage. Also, the temperature of your device will rise and come to equilibrium slowly. These factors are pretty well understood. Often a new piece of equipment will put out a certain smell for a number of hours until various chemicals evaporate from the newly fabricated device. So it is true that some changes can occur in the first days of use.
Also, I would be interested in the comparison of this device to competitive products such as external DACs.
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A quite comprehensive review of the HA-1 here:
https://translate.google.com/transl.../2014/07/10/test-oppo-ha-1/#postTabs_ul_51675
I did not succeed to open yet my device... but I will do it quite soon (as i will have the necessary time for this task). In this review is confirmed that opening the box is not a easy task...
My first comment seeing the pictures of this review, is about inside shielding of HA-1. Very good shielding at least... but made of aluminium. Well, I understand the reasons... Quite common that aluminium do not efficient shield EMI radiations. BTW, the display is a very noisy/EMI generator, as the digital processing PCB.
But as a overall observation (after seeing the inside of the box in these pictures), I may say that is impressive the building of this device, both mechanically, the PCBs, and the connections inside. It shows well that much attention is grant it to each unit in the production lines.
Finally Oppo have find out that the ES9018 works better with a 100Mhz clock... They use this oscillator in HA-1. Very strange that they didn`t done it before in their players...
But more comments from my side, after I will open myself my device...
https://translate.google.com/transl.../2014/07/10/test-oppo-ha-1/#postTabs_ul_51675
I did not succeed to open yet my device... but I will do it quite soon (as i will have the necessary time for this task). In this review is confirmed that opening the box is not a easy task...
My first comment seeing the pictures of this review, is about inside shielding of HA-1. Very good shielding at least... but made of aluminium. Well, I understand the reasons... Quite common that aluminium do not efficient shield EMI radiations. BTW, the display is a very noisy/EMI generator, as the digital processing PCB.
But as a overall observation (after seeing the inside of the box in these pictures), I may say that is impressive the building of this device, both mechanically, the PCBs, and the connections inside. It shows well that much attention is grant it to each unit in the production lines.
Finally Oppo have find out that the ES9018 works better with a 100Mhz clock... They use this oscillator in HA-1. Very strange that they didn`t done it before in their players...
But more comments from my side, after I will open myself my device...
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I emailed Oppo asking about the preamp output stage and they replied saying it's not amplified with the built-in Class-A amplifier, it's only for the headphone output stage.
The preamp uses some Texas not so high end opamps. The support team wasn't able to tell me exactly what opamp is used, but it's a dual opamp.
To make it sounds better, someone would have to mod the HA-1 with something like 2 OPA621SM in a dual-to-mono board and see how it goes. Then, the HA-1 would probably get a state-of-the-art output stage as a preamplifier.
The preamp uses some Texas not so high end opamps. The support team wasn't able to tell me exactly what opamp is used, but it's a dual opamp.
To make it sounds better, someone would have to mod the HA-1 with something like 2 OPA621SM in a dual-to-mono board and see how it goes. Then, the HA-1 would probably get a state-of-the-art output stage as a preamplifier.
the difference in 16/44 and 24/192 distortion in the 1 kHz harmonics at -85/-105 dB doesn't give me much confidence in the measurements - there is no excuse for sample rate/bit depth giving that much difference above -100 dB for a 1 Hz 0 dB signal - doesn't the test signal use dither?
the Sabre DAC does much better and the headphone amp shouldn't respond to the difference in sample rate
further inconsistency is seen in the comparison between the 0 dB and -5 dB plots - the 2nd and 3rd harmonic distortion levels don't scale with harmonic order properly - as they would if a simple analog nonlinearity dominated
2nd should decrease with level in dB 1:1, 3rd 2:1 - while 3rd is unchanged in the 192 plots vs signal level
Thanks for informations. Quite usefully...
Fully agree that is enough place for modifications, even though this device is a high quality product. Always thing can be done better, or improved.
Also I`m very curious what about eventual upgrades for the firmware of HA-1... I couldn`t see anything about this subject, nor from Oppo, or from any of the reviewers.
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Thanks for informations. Quite usefully...
Fully agree that is enough place for modifications, even though this device is a high quality product. Always thing can be done better, or improved.
Also I`m very curious what about eventual upgrades for the firmware of HA-1... I couldn`t see anything about this subject, nor from Oppo, or from any of the reviewers.
Here's what they told me:
Then I asked if they could tell what's the opamp used and the guy replied saying they would contact me on Monday, because he didn't know the opamp used (what's completely reasonable, I don't wait the guy from the costumer service to know something so specific like this) but they didn't.
I will not expect Oppo will want reveal the inside details of a quite new product. What is the exactly designation of the used opamps is not in my opinion, so interesting right now. We will find out anyway, and we will replace it if necessary.
What I can see as important at this time is the fact that only headphone output benefit of a Class A amplifier. About this, I will direct my critic to Oppo designers, who did not founded necessary a switch off mechanism for this Class A amplifier, when the headphone is not in use. Class A amplifier is an energy hungry type of circuit, and is very known as one of the most ineffective way of signal processing. But it have its advantages for a high quality of the processing when to keep the signal integrity.
Definitely this amplifier should be switched off if one will use HA-1 as pre-amplifier, DAC, but not for listening through headphones. An option to give to the user the opportunity to chose to have the high heat dissipation circuit on or off should be in place. I will guess that it could be enough few users who will specially buy this Oppo product for using it exclusively for its headphone Class A output. The majority of buyers will chose to invest in this device to use it as DAC and/or pre-amplifier. My thumbs down to Oppo for this aspect.
I appreciate this it may be the first and most wanted/necessary mod for HA-1: switching on/off the Class A amplifier.
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Well, a new Oppo product is to come quite soon.
Will the modders have a look on it? Of course, positive answer...
As we are already used, Oppo came out with products which gave to modders nice opportunities. So we will see what about, when some more details it will be available for HA-1.
I found already some pictures (it looks like are taken on the prototype), so we may have a first look inside.
Quite compact and solid device, which use analogue PSU(s), mainly an USB DAC with some few other facilities, with a large graphic display (nice). Is to be seen a more sophisticated clock circuit, which it seems to me to generate a main clock signal, and then distributed further to other devices inside (for sure the DAC chip). Is also to be seen that Oppo will no more use the digital volume available for ES9018, but they chosen a more classical way of using the analogue volume. I think is a nice/clever decision.
In the pictures is also to be seen the digital graphic/controller board, while the DAC and PSUs it seems to be on the lower level PCB. Actually this board it may be more interesting for those who knows already few earlier Oppo products. My first observation is that it will not be very easy to access the DAC board in the Oppo`s design of this device. Maybe not just by chance design...
So, let`s wait and see more in the near future...
I don't think it's a nice decision to use an analog volume control. The Sabre 9018 built-in volume control, despite it's digital, is a state-of-the-art volume control. The analog control used can't be compared with the Sabre's in an objective comparsion.
I'm sure that tube lovers would disagree with that, but I'm pretty sure they don't really know the difference between niceness and fidelity. For an analog volume control be more precise than the built-in Sabre ES9018, they would have to invest lots more than a simple Blue Velvet knob (I guess it's what's they're using, but I can't confirm that).
I may not agree about the built in volume control in Sabre chip as a better solution than the analogue volume control. Sabre chip it have in fact a very advanced volume designed circuitry/algorithm to deal with missing digital signal informations (bits) in a simulated digital volume control. They succeed well to control the volume of the digital audio signal in ES90xx chips. But the simplistic ever solution (also huge efficient with no any signal alteration) it still be in analogue domain, done with a very simple device: the potmeter (a decent quality one at least...).
In my opinion, one should use the analogue volume control in any application which it need such, but in the today digital world, this simple device it may become inconvenient...
I still think Oppo did right when about using a analogue volume control for HA-1
In my opinion, one should use the analogue volume control in any application which it need such, but in the today digital world, this simple device it may become inconvenient...
I still think Oppo did right when about using a analogue volume control for HA-1
I will not expect Oppo will want reveal the inside details of a quite new product. What is the exactly designation of the used opamps is not in my opinion, so interesting right now. We will find out anyway, and we will replace it if necessary.
What I can see as important at this time is the fact that only headphone output benefit of a Class A amplifier. About this, I will direct my critic to Oppo designers, who did not founded necessary a switch off mechanism for this Class A amplifier, when the headphone is not in use. Class A amplifier is an energy hungry type of circuit, and is very known as one of the most ineffective way of signal processing. But it have its advantages for a high quality of the processing when to keep the signal integrity.
Definitely this amplifier should be switched off if one will use HA-1 as pre-amplifier, DAC, but not for listening through headphones. An option to give to the user the opportunity to chose to have the high heat dissipation circuit on or off should be in place. I will guess that it could be enough few users who will specially buy this Oppo product for using it exclusively for its headphone Class A output. The majority of buyers will chose to invest in this device to use it as DAC and/or pre-amplifier. My thumbs down to Oppo for this aspect.
I appreciate this it may be the first and most wanted/necessary mod for HA-1: switching on/off the Class A amplifier.
I am one of those that wanted to use it for headphone listening.....but I agree with you 110% on the ability to switch off the class-A headamp. I mentioned this earlier in a post here too. This very likely difficult to implement unless we mod it. But changes like exposing menu options for ES9018 IIR filter selection, plus fast/slow PCM rolloff and even absolute phase --- all are features of the chip that can be brought to the menu with some firmware updates I would think. My guess is that the ES9018 is "stuck" in "fast" mode for PCM, and present more of a brick-wall filter with more pre-ringing and more phase errors with larger group delay. If we could just play with it and move it to "slow" it may open it up more and become even better.
I think the meanings/opinions about how the DAC chip set up it may be, its filters settings, and so on, it can be as many as the readers of this forum... We may trust the algorithms the Oppo designers have chosen for better as possible results. I actually doubt seriously, that it may be possible to modify something in the HA-1 firmware, except Oppo itself will do it. With this aspect we may deal with as it is (unfortunately...).
When about a switch on/off mechanism for the "heater" device, the Class A amplifier, this it could be done very elegant, in the device menu. But for such eventual option, they had to design a relay somewhere in the system. They did not... So, we may forget the "elegant" solution and try to find another one (with a old classical switch).
Or they who did not bought yet the HA-1 will may wait for HA-2 to come... This for sure it will have this option built in... At least we, who own the HA-1, should in fact wait for HA-2 to be on market.
When about a switch on/off mechanism for the "heater" device, the Class A amplifier, this it could be done very elegant, in the device menu. But for such eventual option, they had to design a relay somewhere in the system. They did not... So, we may forget the "elegant" solution and try to find another one (with a old classical switch).
Or they who did not bought yet the HA-1 will may wait for HA-2 to come... This for sure it will have this option built in... At least we, who own the HA-1, should in fact wait for HA-2 to be on market.
I don't know if it's possible, perhaps I'm saying ********, but someone who already own the HA-1 maybe should buy a 4pin mini XLR to 2x XLR or 2x RCA and try to use the headphone output to act like a preamplifier output.
If it's possible, the HA-1 would act as a Class-A preamp, and a really good one. Or perhaps I'm saying ******** and it's something really insane to think, haha!
If it's possible, the HA-1 would act as a Class-A preamp, and a really good one. Or perhaps I'm saying ******** and it's something really insane to think, haha!
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