Is it related to this?
For the unbalanced RCA stereo output, OPPO hired an audio consultant who developed a certain way to bias the components so it actually sounds and measures better than the BDP-95, but requires an AC coupled output.
BDP-105 Hardware FAQ - OPPOwiki
Sounds about right. I thought it was a mistake at first. However, THIS stage DOES sound pretty good, better than most.
It still yet to be found out why... But the same setup it could be used on all of the output channels, not only stereo... It is missing something in this puzzle😉
...And this way of doing it may explain why it were not needed the unpolarised coupling caps... (?) But then the multichannels?
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"For the unbalanced RCA stereo output, OPPO hired an audio consultant who developed a certain way to bias the components so it actually sounds and measures better than the BDP-95, but requires an AC coupled output."
It wasn't me, honest. 😀😀😀
John?
.
It wasn't me, honest. 😀😀😀
John?
.
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I thought it was a mistake, so I took it to Jason. He said: No mistake. That is apparently why they added the output cap. However, I found that the 'asymmetrical' drive sounded pretty good, so what is there to say?
In truth, this is not an audio circuit built to the level of a Parasound JC series, but then, it costs about 1/4 as much, so it is one heck of a bargain.
As you have found, it could be better, but hardly without more cost. Of course, there could be different tradeoffs at the same price point.
I gave OPPO a list of my own as to how to 'improve' the circuitry, but they were subtle, and probably would not change the MEASURED specs significantly. It will take time for them to realize that SPECS alone does not make a perfect player. I can't blame them, look at all the people here who can't appreciate subjective evaluation, and only believe in engineering solutions, the cheaper the better?
I evaluated the 105 with SACD, DVD, and Blue Ray. It was pretty good, BUT it could be better for AUDIO ONLY.
Keep up the good work, Joe and Coris. Perhaps you will find, as I have, over the years, that if you do a good job, you will get insults and opposition, but people will adopt it, as if it had been 'obvious', sooner or later. '-)
The engineers at OPPO are smart, but limited in hi end experience.
In truth, this is not an audio circuit built to the level of a Parasound JC series, but then, it costs about 1/4 as much, so it is one heck of a bargain.
As you have found, it could be better, but hardly without more cost. Of course, there could be different tradeoffs at the same price point.
I gave OPPO a list of my own as to how to 'improve' the circuitry, but they were subtle, and probably would not change the MEASURED specs significantly. It will take time for them to realize that SPECS alone does not make a perfect player. I can't blame them, look at all the people here who can't appreciate subjective evaluation, and only believe in engineering solutions, the cheaper the better?
I evaluated the 105 with SACD, DVD, and Blue Ray. It was pretty good, BUT it could be better for AUDIO ONLY.
Keep up the good work, Joe and Coris. Perhaps you will find, as I have, over the years, that if you do a good job, you will get insults and opposition, but people will adopt it, as if it had been 'obvious', sooner or later. '-)
The engineers at OPPO are smart, but limited in hi end experience.
Now I see... The (one) consultant were hired to develop the unbalanced RCA stereo output. So the multichannels stage it were developed of another consultant... The headphone another one, and so on...😀😀😀
There are quite many stages in this player...😉
This may explain the differences...😀
There are quite many stages in this player...😉
This may explain the differences...😀
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In the last time I`ve got the ordered SAWs 54Mhz (50ppm).
After a while, I have listened to my modified player with another standard oscillators (both 54 and 108Mhz).So, I have mounted this SAW in place. I may confirm once more time that the SAW give definitely the best sound out of this player. There is now obviously (at least for me)!
The sound is more pleasant to listen, and if I can say so, warmer or sweeter. There is something with this oscillator which it make the ESS9018 to sound even better. Highly recommended.
Waiting now to get the custom made 108Mhz one from Seiko Epson (but it will take a little longer time...). Then a clock kit it may/will be ready...
After a while, I have listened to my modified player with another standard oscillators (both 54 and 108Mhz).So, I have mounted this SAW in place. I may confirm once more time that the SAW give definitely the best sound out of this player. There is now obviously (at least for me)!
The sound is more pleasant to listen, and if I can say so, warmer or sweeter. There is something with this oscillator which it make the ESS9018 to sound even better. Highly recommended.
Waiting now to get the custom made 108Mhz one from Seiko Epson (but it will take a little longer time...). Then a clock kit it may/will be ready...
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Using SAW 54Mhz oscillator divided to clock the main processor, I can notice also improvements in picture stage. The divider I use for the moment is not very performant. Even though there are improvements for colors, contrast, and black level.
Coris / Joe,
This pleasant / warm / sweet sound is the -addition- of certain types of
jitter. There is no doubt about it IMHO.
It's not a bad thing, it just is.
cheers
T
Yes, it seems that a some jitter level in clocking oscillator it may be benefit for the perceptual quality of the sound. This may come in quite high contrast with the purists concept to remove out that jitter as much as possible... Maybe one may take a more closer look at this aspect.
There is something else here. Those chips involved in sound and picture of this player (or maybe in general) have incorporated oscillators driven by an resonator. I just think that incorporated oscillator it may have a very low jitter and is for sure not perturbed by long transmission lines, or other factors as an external oscillator it may be. Even though it seems that those chips it work better with an external oscillator, which it looks like have increasing jitter in some cases.
It is is not excluded here at SAW, which is of a special sort oscillator, it may contribute to an increasing perceptual quality of the (in this case) sound first in this system, just because of its special other properties, but not first because of low jitter. I could also notice increasing in the picture quality using such oscillator. We may not forget that this oscillator is made special for environments exposed to quite important vibrations of all sorts. Its property to have immunity to those perturbations it may be another reason which contribute to obtaining a quality perception of the resulting sound.
Those things it may need a better analyze, and best way to prove or deny such aspects is only if more users will want to try in fact this oscillator type, inspite theirs purist concept about a free jitter clock in an audio system, or that a very commercial oscillator it may not be compatible with high end/quality devices. This it may bring more impressions out to judge about, and can actually leads to a more reasonable conclusion.
I would really like to hear from somebody else: well, I have soldered a such SAW oscillator in my system, and I`m not satisfied at all. Only bead... and explain why.
There is something else here. Those chips involved in sound and picture of this player (or maybe in general) have incorporated oscillators driven by an resonator. I just think that incorporated oscillator it may have a very low jitter and is for sure not perturbed by long transmission lines, or other factors as an external oscillator it may be. Even though it seems that those chips it work better with an external oscillator, which it looks like have increasing jitter in some cases.
It is is not excluded here at SAW, which is of a special sort oscillator, it may contribute to an increasing perceptual quality of the (in this case) sound first in this system, just because of its special other properties, but not first because of low jitter. I could also notice increasing in the picture quality using such oscillator. We may not forget that this oscillator is made special for environments exposed to quite important vibrations of all sorts. Its property to have immunity to those perturbations it may be another reason which contribute to obtaining a quality perception of the resulting sound.
Those things it may need a better analyze, and best way to prove or deny such aspects is only if more users will want to try in fact this oscillator type, inspite theirs purist concept about a free jitter clock in an audio system, or that a very commercial oscillator it may not be compatible with high end/quality devices. This it may bring more impressions out to judge about, and can actually leads to a more reasonable conclusion.
I would really like to hear from somebody else: well, I have soldered a such SAW oscillator in my system, and I`m not satisfied at all. Only bead... and explain why.
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Well, maybe somebody with access to a jitter analyzer could compare the jitter of a crystek oscillator to that of a saw oscillator in the presence of vibration (such as sitting on top of a Blu-ray player).
Zen electro,
Which oscillator would you recommend in this situation (Inside the oppo105)? How about the crystek 950? The published jitter specs look good. How good is the original crystal?
Which oscillator would you recommend in this situation (Inside the oppo105)? How about the crystek 950? The published jitter specs look good. How good is the original crystal?
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OPPO analog circuit board mods
A while back I asked if anyone had close-up pictures of the OPPO analog circuit board in an attempt to hunt for and eliminate ground loops. Sadly, no one responded. 🙁
However, I did purchase a BDP-103 and returned it for a BDP-105. Both boards use the "ground plane" philosophy where ground material is retained after etching traces. While good for RF and digital designs, this is NOT good for analog audio. So the answer to eliminating ground loops on the analog circuit board is this: not possible, or at least this side of impossible.
This is unfortunate since the CB layout could be accomplished with different software that did not introduce this problem.
Read more in my blog at Audiophile Musings.
A while back I asked if anyone had close-up pictures of the OPPO analog circuit board in an attempt to hunt for and eliminate ground loops. Sadly, no one responded. 🙁
However, I did purchase a BDP-103 and returned it for a BDP-105. Both boards use the "ground plane" philosophy where ground material is retained after etching traces. While good for RF and digital designs, this is NOT good for analog audio. So the answer to eliminating ground loops on the analog circuit board is this: not possible, or at least this side of impossible.
This is unfortunate since the CB layout could be accomplished with different software that did not introduce this problem.
Read more in my blog at Audiophile Musings.
I think you are picking on Coris' choice of words here - and they are not necessarily the words I would choose, because I can also add that the SAW sound more blunt and merciless. Not sweeter in the sense you have picked up.
Having heard what Coris has heard, I can see what he means, but I can also see how it could give you the wrong idea.
I have both the Crystek 957 100MHz & SAW 100MHz here - if anything it is the Crystek that sounds more forgiving, and smooth and nice, the SAW is more revealing, even being more explicit, but adds no digititus. David in Malaysia (he sent me the Crystek) agreed with me that the Crystek is on the soft side, but there is no similar "sweetness" with the SAW. (RAW rhymes with SAW - and that is also a good description of what is heard.)
But Terry, you haven't even heard what the SAW does... whatever the academic reasons behind it (the numbers game, which you know I don't dismiss because I actually would like to get to the bottom of the matter - I am definitely of the opinion that here is something that DOES need to be figured out), it does sound different, but not in the way you seem to imagine.
The idea of adding in-band (relatively speaking) jitter, is something I have no gripe with you and if you remember back, I have said for many, many years, even said it to Allen, that adding jitter didn't necessarily add anything we would describe as digital sound. Indeed it added colouration in the same way that two well designed speakers can have identical flat frequency response, both measure well to the point of perfection (in the a thought-experiment way) etc, and yet STILL sound different. Different cone materials etc, and more, all will add their colour, hence colouration, yet both speakers may be highly enjoyable to listen to.
Now what you are saying is not much different from that. I even posed a question with you that two players (DACs or whatever) A and B, that many would pick B even though it may have more jitter than A because the jitter is spectrally different for the two players. And you AGREED. So I don't see us being very much afar. I know where you are coming from and not picking an argument with you.
(For those who don't know, I come from a loudspeaker design background.)
So... the bad sounding jitter seems to be out of band stuff - extreme high? Or, as I suspect by observation, extreme low? Or...?
I would honestly like to know - my gut instinct is that here is something that should be tackled - and maybe those who can (you?) may need to shift a little ground and... bottom line, is there something we have overlooked?
So I ask the questions, and appeal for answers, and whoever comes up with that answer will be owed a lot by the rest of us. I would love that to be you. Because I am dealing with something here that I don't have answers - but it cannot be dismissed either.
Cheers, Joe
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That may be worth a try. My gut feeling is that the analyser needs to read what happens below 1 Hertz.
The thing that caught eye when coming across SAW oscillators, was that the word "stability" was repeated (as was superior durability - and their suitability for military application under harsh conditions) and that the implication that the ability to oscillate at much higher frequencies requires greater elemental stability in the device. Yet, when we consider exactly what stability is, it is in fact a DC like quality. Maybe that is a a bit difficult for some people to wrap their mind around, but in seismic terms, ultimate stability is rock-hard DC.
I have worked for companies that had electron microscopes, they had to be put on a special platforms, often in-bedded into the ground, highly reinforced and vibration proof, even to the point of having anti-resonators built-in. This lead to the idea of us using the term Terra Firma to identify stability in clocking. I even wrote an article about four years ago - can supply link.
If they had never used that word, then we would not be discussing SAWs right now.
But your thought of microphonics being a factor, that certainly is not to be dismissed.
Yet, that ability to be stable so as to oscillate at much higher frequencies that conventional BAW oscillators, guaranteed to under near all kinds of environments, THAT has to be a key.
Alas, at this stage, realistically, only the ESS Sabre DAC is compatible. No SAWs lower than 50MHz.
Cheers, Joe
PS: Maybe Coris can comment, but the SAWs also sounds like they give the music greater stability. Bass lines, complex rhythmic patterns, vitality, all the usual PRAT comments applies, it makes the SAW more involving, gets your foot tapping... all this and the thought of stability is almost a natural.
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Agree! As I mentioned in posts 228 and 230, I was one of those unsure about the SAW after doing a back to back shoot-out with Crystek. Since then the SAW has won me over.
Right out of the box, the SAW had the advantage over the Crystek in the most of the areas Joe identified above. My early concerns with the SAW was that it sounded "tonally grey" and was not as musically engaging. However, after longer term evaluation and having the dacs powered up for several days, the issues with the lack of tonal colour and musicality went away on the SAW clocked dac.
IME, the SAW will sound grey and less musical than the Crystek on initial power up and for many hours after. The solution is to leave the dac on permanently.