Tested 105 DAC with 108Mhz clock. The main processor it still have its own 27Mhz oscillator. I do not have yet the divider by 4 to get the right clock out of 108Mhz oscillator.
It work just wonderful! No mater one or another will/still say, there is very obviously that higher clock frequency for ESS9018 it improve the quality of the sound dramatically.
The test it were made by only replacing the old oscillator with 108Mhz one. The clock circuitry have to be modded accordingly for best functioning. I did not yet, and used the Oppo`s design as it is for instance. I still have some random drop out, but out of those, the improvement in sound using this high frequency clock is huge. Specially in soundstage, details, separation and definition.
It seems that the differential circuit used to send out the clock to the multichannels DAC it have some problems with 108Mhz frequency, even though the chips used are specified for 200Mhz. It may be the imperfection of my testing setup, which it cause this... When will come the divider I will do it right this mod...
As a conclusion, everything point to 108Mhz clocking/dividing as the best way in this case.
It work just wonderful! No mater one or another will/still say, there is very obviously that higher clock frequency for ESS9018 it improve the quality of the sound dramatically.
The test it were made by only replacing the old oscillator with 108Mhz one. The clock circuitry have to be modded accordingly for best functioning. I did not yet, and used the Oppo`s design as it is for instance. I still have some random drop out, but out of those, the improvement in sound using this high frequency clock is huge. Specially in soundstage, details, separation and definition.
It seems that the differential circuit used to send out the clock to the multichannels DAC it have some problems with 108Mhz frequency, even though the chips used are specified for 200Mhz. It may be the imperfection of my testing setup, which it cause this... When will come the divider I will do it right this mod...
As a conclusion, everything point to 108Mhz clocking/dividing as the best way in this case.
I think your supposition it seems reasonable. It may be this a possible explanation, but...
As their design is, and how those channels are functioning (RCA channels), I appreciate that it may be enough difficult to be heard such delicate details of sweetness in sound on that output. In original design the soundstage is very poor, the definition is also low, and even the fidelity is not as high that a listener could hear it that sweetness or not in the resulting sound.
There is need of quite large modification to make the RCA channels and the DAC to sounds good...
In my analize of that circuit, I can see that one of the phases (out of the I/V converter) it have a double level comparing with another one coming from DAC differential output. The resulting AC signal it have the + or - part in it higher (unbalanced) than the opposite. This is about resulting AC signal after the output caps. Let`s not forget that the coupling caps isolate the DC from AC on that outputs. Or let pass only the AC out.
There is specified in datasheet of ESS9018 (and this is enough obvious in such differential design) that the signals out of the DAC it have to be treated symmetrical/identical, to benefit of the DAC specifications and design.
I really think that there is a really mess on that output, because this resistors unbalance in its I/V converter. And this it may be reflected in quite obvious poor soundstage on RCA.
So let`s waiting for more opinion on this subject before a conclusion...
As their design is, and how those channels are functioning (RCA channels), I appreciate that it may be enough difficult to be heard such delicate details of sweetness in sound on that output. In original design the soundstage is very poor, the definition is also low, and even the fidelity is not as high that a listener could hear it that sweetness or not in the resulting sound.
There is need of quite large modification to make the RCA channels and the DAC to sounds good...
In my analize of that circuit, I can see that one of the phases (out of the I/V converter) it have a double level comparing with another one coming from DAC differential output. The resulting AC signal it have the + or - part in it higher (unbalanced) than the opposite. This is about resulting AC signal after the output caps. Let`s not forget that the coupling caps isolate the DC from AC on that outputs. Or let pass only the AC out.
There is specified in datasheet of ESS9018 (and this is enough obvious in such differential design) that the signals out of the DAC it have to be treated symmetrical/identical, to benefit of the DAC specifications and design.
I really think that there is a really mess on that output, because this resistors unbalance in its I/V converter. And this it may be reflected in quite obvious poor soundstage on RCA.
So let`s waiting for more opinion on this subject before a conclusion...
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.
I have another theory, that it has to do with slew rate problems that are inherent to opamp/feedback I/V - I remember well nodding my head when Charlie Hansen of Ayre on the Hi-Rez Audioasylum forum fingered this as a major contributor to 'digital' sound and found myself saying "hear hear."
Also, using single phase means 780 Ohm output from the DAC and that in some say that they find single phase sounding better, BUT they all have something is common, they are using opamp/feedback I/V, or "virtual earth" rather than real earth. I can see what they, Oppo, are doing is helping to attenuate or reduce slew rate induce distortion, that is that less "heat" is seen by the opamp. At very high frequencies, the feedback simply cannot respond fast enough, they also have an internal comp cap that induces 90 degree phase angle that eventually erodes beyond 90 degrees causing even worse headroom at HF. Even well before it gets truly bad, it still starts to make things sound flat and grey, the colours gets bleached etc.
My suggestion is using this arrangement below - zero feedback. The gain block is actually based on a zero feedback Phono Stage sans RIAA EQ - the two resistors sum at around 6 Ohm, which just happens to be about the source impedance of a very fast Ortofon MC cartridge. This is no coincidence.
Cheers, Joe
I have another theory, that it has to do with slew rate problems that are inherent to opamp/feedback I/V - I remember well nodding my head when Charlie Hansen of Ayre on the Hi-Rez Audioasylum forum fingered this as a major contributor to 'digital' sound and found myself saying "hear hear."
Also, using single phase means 780 Ohm output from the DAC and that in some say that they find single phase sounding better, BUT they all have something is common, they are using opamp/feedback I/V, or "virtual earth" rather than real earth. I can see what they, Oppo, are doing is helping to attenuate or reduce slew rate induce distortion, that is that less "heat" is seen by the opamp. At very high frequencies, the feedback simply cannot respond fast enough, they also have an internal comp cap that induces 90 degree phase angle that eventually erodes beyond 90 degrees causing even worse headroom at HF. Even well before it gets truly bad, it still starts to make things sound flat and grey, the colours gets bleached etc.
My suggestion is using this arrangement below - zero feedback. The gain block is actually based on a zero feedback Phono Stage sans RIAA EQ - the two resistors sum at around 6 Ohm, which just happens to be about the source impedance of a very fast Ortofon MC cartridge. This is no coincidence.
Cheers, Joe
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For instance I have this comments at Joe`s theory.
The LM4265 opamp slew rate is specified at 20V/µs. This slew rate is strong attenuated by the caps (original design) in the feedback (paralleled with the I/V resistor). The resulting slew rate at the I/V output it may be quite low anyway.
Although an gain of 250 in this stage it may (in my opinion) increase too much the noise... But I think to give it a try.
The LM4265 opamp slew rate is specified at 20V/µs. This slew rate is strong attenuated by the caps (original design) in the feedback (paralleled with the I/V resistor). The resulting slew rate at the I/V output it may be quite low anyway.
Although an gain of 250 in this stage it may (in my opinion) increase too much the noise... But I think to give it a try.
Yes, noise can be a factor with gains like this. I had the first VSE modded Yamaha in the US here for more mods. The gain was set for 1Vrms. I could hear the hiss from the circuit at 6-7 feet away at listening level. I removed half of the resistors to ground and got 2VRMS. Then I could hear the noise at 3 feet from the speaker.....not too bad. The circuit I was using at the time in my Oppo with 2V out gave no hiss.....no noise.....at least 20db or better signal to noise than the VSE circuit. The AD844s used without feedback is very clever. Sound wise not to bad either.
Using 844's without feedback is a long way from clever and also doesn't
take full advantage of the DAC. The 844 has very low internal bias currents
which will basically make a nice euphonic distortion box when used open
loop.
In grounded base / virtual gnd configuration as per the other thread using
1704, the improvements gained via stacking 844's confirm my statement.
By stacking, you are effectively creating a virtual single chip of higher bias
current. I have spoken to Joe about this years ago suggesting a discrete
circuit to be a better option. The one advantage of 844 is it has very low
offset so can be set up direct coupled with some additional circuitry.
In non inverting mode, ie; voltage mode same applies, internal bias currents
will mean for a gain of x 250 there will be a lot of distortion. This will be all
low order so the euphonic thing will be in action.
Squeezing everything down to 2x3 ohms will result in a pretty big reduction
in dynamic range of the chip. Quick calcs estimate the chip will go from
>125 dB DR to around 90dB.
Does this matter is a big question - ATM the best replay I've heard is analog
tape, having all of 70dB DR (if you are lucky) and lot's of distortion - so I
suppose that's audio for you!
Z
Excuse me, but did I ever say that I use a gain of 250?
I am discussing a thought-experiment re a single (or per phase) and I already did mention the need to attend to noise.
Of course I am NOT suggesting a noisy solution. Wherever did that idea come from? Cheez...
C'mon - I wasn't born yesterday.
Anybody is welcome to come here and stick their heads right inside the cones of my rather efficient speakers !!!
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Yes, indeed. Your post above shows the circuit with X250 in it.
The original VSE circuit you used in the Sony and Yamaha players used 844s with no feedback (one per phase). I have the schematic here. It was noisey with the Burr-Brown DAC in the Yamaha. If you are using a different circuit that is less noisey than that circuit....it would be a good thing.
What I use is a single J-fet buffer (current sourced with another J-fet, you know the basic B1 direct coupled circuit...been around for years and years).....yes, I only get 1V RMS per phase but....oh my, the palpability is through the roof. Every part needs to be state of the art and using the best shunt regulators with no electrolytic caps on the output of the regulator. Super simple....super good. As long as you use a preamp, you are fine. Passive preamp use or directly to amp use may not have enough volume. Try it! Never heard better, including transformers, other discrete stages and the VSE 844 circuit.
The original VSE circuit you used in the Sony and Yamaha players used 844s with no feedback (one per phase). I have the schematic here. It was noisey with the Burr-Brown DAC in the Yamaha. If you are using a different circuit that is less noisey than that circuit....it would be a good thing.
What I use is a single J-fet buffer (current sourced with another J-fet, you know the basic B1 direct coupled circuit...been around for years and years).....yes, I only get 1V RMS per phase but....oh my, the palpability is through the roof. Every part needs to be state of the art and using the best shunt regulators with no electrolytic caps on the output of the regulator. Super simple....super good. As long as you use a preamp, you are fine. Passive preamp use or directly to amp use may not have enough volume. Try it! Never heard better, including transformers, other discrete stages and the VSE 844 circuit.
Ric
What you say has NOTHING to do with me. Unless I have that Yamaha player here I can make ZERO comment. So why are you AGAIN having a go at me - on the basis that a diagram shows "x250" which was not intended to be extrapolated into something you found in a Yamaha player I have NEVER seen.
I have never done a Yamaha in the way you describe. You are describing something seriously defective and ascribing it to me, who have not laid a hand or eye on it?
I am quite willing to be judged by what *I* do, in fact I am all the time.
It seems to me that YOU, Ric, are constantly trying to find an angle to have another go at me. Now I cannot even do a theoretical schematic (not an actual circuit), and once again you POUNCE !!! ???
IF you are trying to silence me? Then maybe that is working, so that I cannot freely express myself with the thought "oh oh, maybe I will get another slur from Ric?" - then I shall not have anything to do with this forum again.
That's all.
Too bad, because I do believe I have contributed something.
But I don't need this. I don't rely on this forum and is kept quite busy enough by people who appreciate what I do.
And not one has complained about noise? Where in the netherworld did that come from?
What you say has NOTHING to do with me. Unless I have that Yamaha player here I can make ZERO comment. So why are you AGAIN having a go at me - on the basis that a diagram shows "x250" which was not intended to be extrapolated into something you found in a Yamaha player I have NEVER seen.
I have never done a Yamaha in the way you describe. You are describing something seriously defective and ascribing it to me, who have not laid a hand or eye on it?
I am quite willing to be judged by what *I* do, in fact I am all the time.
It seems to me that YOU, Ric, are constantly trying to find an angle to have another go at me. Now I cannot even do a theoretical schematic (not an actual circuit), and once again you POUNCE !!! ???
IF you are trying to silence me? Then maybe that is working, so that I cannot freely express myself with the thought "oh oh, maybe I will get another slur from Ric?" - then I shall not have anything to do with this forum again.
That's all.
Too bad, because I do believe I have contributed something.
But I don't need this. I don't rely on this forum and is kept quite busy enough by people who appreciate what I do.
And not one has complained about noise? Where in the netherworld did that come from?
There is a book by Miguel Angel Ruiz called The Four Agreements. I highly recommend everyone read it. The "truth" shall set you free. What others say is just a bunch of words (including these)....if we take it too personally then we lose ourselves. We don't need to defend ourselves. We are beautiful, just the way we are. I am sorry, if you feel I have some personal thang going on here. I am interested in the truth, all truths including audio truth (our direct listening experience is the only truth in audio), yes....but more and absolutely the most important thing to get is how incredible you are. We are beautiful beyond words. Life is incredible! 3 humans being born every second. How many ants? How much love and joy is there? Is it infinite? Seems so.
Yes, nothing I say has anything to do with you. It is what you say to yourself, moment to moment that determines your happiness. I wish you nothing but happiness.
Yes, nothing I say has anything to do with you. It is what you say to yourself, moment to moment that determines your happiness. I wish you nothing but happiness.
No, of course... I'm not even say that... I expressed my opinion to the information/idea/picture in your post... It is only a discussion.
Sorry Joe, you may not take all this discussions so dramatically. Is only changing the ideas. That`s all. Nobody accuse. Just "for" and "against" opinions... I can not see something wrong in this. But anyway, you are free to have your own opinion too...
You have seen this before for sure: There is a guy here who felt the need (he think maybe he can save the world from the Bad guy) to follow almost all my contributions in few threads in a time been, and attacked that systematically. I have been accused to do foolish thing, unprofessional, and so on... I think it is a big difference between such behaviours and having discussions about a subject or another. One may be free to express his opinions, and accept other opinions too. There is the main meaning in a Forum...
You have seen this before for sure: There is a guy here who felt the need (he think maybe he can save the world from the Bad guy) to follow almost all my contributions in few threads in a time been, and attacked that systematically. I have been accused to do foolish thing, unprofessional, and so on... I think it is a big difference between such behaviours and having discussions about a subject or another. One may be free to express his opinions, and accept other opinions too. There is the main meaning in a Forum...
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No, of course... I'm not even say that... I expressed my opinion to the information/idea/picture in your post... It is only a discussion.
Exactly - it was only a discussion.
It was not about any Yamaha that I have never laid eyes on.
Good question(s).
With the '105 a lot of avenues open up. For the '95 I most put all my files on a 2TB hard drive and all of them at my finger tips - about 1400+ CDs and albums, a fair sprinkling of 24/96 and 24/192 Flac files. It's great.
But the '105 there are things that I now have to come to grips with. I was thinking JRiver as I have a friend who is already down that way - he says that it uses 64 bit processing. But pushing content is also very new to me.
It just shows that we hard-ware guys may also need help in certain directions? I do know that the '105 is going to see me exploring a lot of stuff.
Cheers, Joe
Yes, I would appreciate some 'help' here too. We now have this player, and a lot of content anywhere else on the home network. So the sensible thing for me would be to have a controller, say a tablet, where I could select content from anywhere, be it USB or network drives, PCs, the hard drives connected to the Oppo, and then have it played on the Oppo. Seems straightforward but after a day of searching the only one I found that can do that is KooRaRoo I mentioned.
The terminology is DMR for Digital Media Renderer (the Oppo is one), and DMC, Digital Media Controller, and KooRaRoo is one. Importantly, the digital content is NOT going through the DMC - the DMC merely connects content to player. The process is called 'pushing content'. See also page 44 in the Oppo handbook (my EU version handbook).
jan
The terminology is DMR for Digital Media Renderer (the Oppo is one), and DMC, Digital Media Controller, and KooRaRoo is one. Importantly, the digital content is NOT going through the DMC - the DMC merely connects content to player. The process is called 'pushing content'. See also page 44 in the Oppo handbook (my EU version handbook).
jan
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When you say "push", you refer to network connection I suppose. If so, there is quite simple thing this (for both 95 and 105). Thanks to Foobar (and its developer)... This software is just exceptional and free...
Install Foobar with "UPnP/DLNA Renderer, Server, Control Point" and "UPnP Media renderer output" plugins. You may want of course some other plugins too... Setup right the Foobar itself (preferences - streaming profiles)...
Make a playlist in to it. Close Foobar down. Start it up again. Startup 105 and connect it to network. You will see there Foobar in Oppo`s network connections. Run that and choose your playlist. Enjoy! If you want "shuffle" that works too (on 95/105). You can even listen to Web Radio this way through Oppo (streaming). Quite impressive quality on 256kBs stations (44,1Khz sampling). Record that, and convert it to FLAC 176.4Khz (with some few treatments...). WOW!
You have so the music on your computer, where you can manage it very easy, playing it back out on your Oppo player.
You can do almost the same through 105 USB input, but so how it is this USB interface it have a quite poor quality comparing with the network connection. This is enough easy to understand, but I do not develop it now this subject here... Better through network anyway. Not at least is not very recommended to have long distances on USB connections. Quite often one have the computer enough far from his rack. Better with CAT 6,7,8 cables... and 1Gb speed on router. I prefer cables rather than wireless...
But one it almost have at least to modify the player to get much better quality out of it. I personally can not even tolerate to hear a standard 105 anymore, after I modified it mine. The difference is only huge! And I`m not yet finish to modified it...
I just suppose that one it may not want/prefer to "push" to Oppo 105 some 128kBs mp3 files...
I will recommend to everybody (who can and buder) to use a enough proof computer software to convert his sources (CDs) to FLAC 176.4KHz /24bit (fix the levels on channels and so - a little bit of "lifting" of the original file). Is quite frequent that so called good recorded CDs it still have some levels problems in it. This is bad!
So, send to Oppo that FLAC 176.4KHz /24bit file. So it have to be to one really enjoy a good quality. It may be even better with Wav files, but it is quite space consuming this way...
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Coris, when I understand you correctly, you play the files through the Oppo's interface (presumably your TV). I don't want that, it is too limited, you can't easily go through all your content and have graphical view of your library; it's more like Windows Explorer.
I want to use a graphically organised app like (sorry) iTunes) on a tablet, where I have all my content clearly available and 'push' it to the Oppo.
This explains the process: What is a Media Controller? | Home Theater
jan
I want to use a graphically organised app like (sorry) iTunes) on a tablet, where I have all my content clearly available and 'push' it to the Oppo.
This explains the process: What is a Media Controller? | Home Theater
jan
I will finally say that the network connection is the best reliable than all other 105 it have (audio). There are some (buffer) problems in 105 firmware which make the use of quite slow hard drivers not very fortunate. It works better this interface with SSD (USB converter). The USB input is better, but not enough good quality (unmodified). I miss on 105 the SATA port. So it still the LAN interface the best on this player. My opinion...