I agree. There's one important element that's been omitted from your observation - ground plane potential uniformity / ground plane noise. If done properly, a local decoupling can achieve an excellent result - much greater than implementing only very low noise voltage regulators.
Power supply pins on all IC’s should sit at ground noise potential – not higher than that, if a local decoupling is executed properly. Then, there’s actually only one question: How low is the ground plane noise?
I dislike kits that consist of many modules, like buffalo and similar – with these, it is impossible to achieve ground potential uniformity – the main reason why Coris achieved suboptimal results in BD95 with placid / placid bp. There’s the heat as well, which renders these modules useless in consumer electronic products, unless a special care is taken to dissipate the heat (fans!); I don’t think many DIY-ers are aware of this “heat-factor” when they are ordering shunt regulators on line.
Low noise power supply regulation should be executed on the main board; shunt types can also be used, but catered at design stage from the get-go, as heat generators) – only then the low nose benefits of such power supply can be distributed to where it is really needed – at all IC’s / discrete stages – this is the whole idea.
Boky
Power supply pins on all IC’s should sit at ground noise potential – not higher than that, if a local decoupling is executed properly. Then, there’s actually only one question: How low is the ground plane noise?
I dislike kits that consist of many modules, like buffalo and similar – with these, it is impossible to achieve ground potential uniformity – the main reason why Coris achieved suboptimal results in BD95 with placid / placid bp. There’s the heat as well, which renders these modules useless in consumer electronic products, unless a special care is taken to dissipate the heat (fans!); I don’t think many DIY-ers are aware of this “heat-factor” when they are ordering shunt regulators on line.
Low noise power supply regulation should be executed on the main board; shunt types can also be used, but catered at design stage from the get-go, as heat generators) – only then the low nose benefits of such power supply can be distributed to where it is really needed – at all IC’s / discrete stages – this is the whole idea.
Boky
For sure, the ground potential uniformity is (have to be) a must for good results. Shunt regulator can be a good solution, but is not when is about a main PSU. It is working very well and are quite efficient if are used as local regulators (right beside the chip/device of interest). In such case is about quite low currents and heat dissipation can be minimal. One may chose the right solution, because is very possible to obtain very good results with a serial one...
Yes, in case of BDP95, the placement of the DAC chip and some other devices are quite far from the main PSU. A good ground plane, with a low potential is a problem here. Also the ground plane is to be designed accordingly. Is not only about have a coper plane as well...
I adopted a solution with a 1,5 square mm silver ground wires (shortest as possible) from main (+/-) PSUs, which meet together in the chosen common (radial) GND point . It works well so far for me.
The main PSU is only to be a main one, and the local supplementary regulation is applied in the points of interest. I chosen serial low noise chip regulators, because they are more practical and easy to apply. Even more,such type regulators tolerate very well large decoupling capacities (which also are a must in some cases) in my opinion.
Yes, in case of BDP95, the placement of the DAC chip and some other devices are quite far from the main PSU. A good ground plane, with a low potential is a problem here. Also the ground plane is to be designed accordingly. Is not only about have a coper plane as well...
I adopted a solution with a 1,5 square mm silver ground wires (shortest as possible) from main (+/-) PSUs, which meet together in the chosen common (radial) GND point . It works well so far for me.
The main PSU is only to be a main one, and the local supplementary regulation is applied in the points of interest. I chosen serial low noise chip regulators, because they are more practical and easy to apply. Even more,such type regulators tolerate very well large decoupling capacities (which also are a must in some cases) in my opinion.
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I have to say that improvements in audio performances it not may come to much only from the replacements of the op amps. What is used in Oppo`s devices are enough good quality active components. What is the weak part of those Oppo players is the power system, and the quality of the clock oscillators. Actually (as I guess...) Oppo 93 have only an switching PSU which supply for the audio stage too... This is not very good solution.
If you will try to improve the power system, with good/consistent local decoupling for the involved components, and maybe replace the respective clock oscillators with another ones (better specs), then will for sure be an quite big improvement in the analogue audio output (and video too).
You may try to replace only the main oscillator for the DAC chip with another one (80 or 100 Mhz) and you will have at once an improvement (with the same op amps).
full linear power mod and TCXO( OCXO) mod for OPPO 93/95
An externally hosted image should be here but it was not working when we last tested it.
I I I am happy to report to I have modified OPPO 93 with full linear power and i replaced 20( HDMI part ), 25 ( CPU ) MHZ with 2.5 PPM TCXO.Some interesting and quite deep discussion on de-coupling here, further on in the thread are numerous links and comments on digital supply decoupling.
http://www.diyaudio.com/forums/power-supplies/106648-paralleling-film-caps-electrolytic-caps.html
Digital systems generate thier own noise, I would also look up simultaneous switching noise, and the numerous data sheets, app notes and white papers on how to controll it.
http://www.diyaudio.com/forums/power-supplies/106648-paralleling-film-caps-electrolytic-caps.html
Digital systems generate thier own noise, I would also look up simultaneous switching noise, and the numerous data sheets, app notes and white papers on how to controll it.
Nice! Can you reveal your sources for the 2,5ppm oscillators? Some impresions about picture/video improvements, concerning replacement of 20Mhz clock - HDMI?
(Is something wrong with your picture attached here. Not possible to open).
http://blog.paran.com/blog/list/listBoard.kth?pmcId=pcaudio
here is the link of my fully modfied oppo 93.
here is the link of my fully modfied oppo 93.
[FONT=함초롬바탕]Full linear power mod was very difficult task.[/FONT]
[FONT=함초롬바탕]It took about 6 months from scratch.[/FONT]
[FONT=함초롬바탕]I am audio and home theater enthusiasts over 30 years have Ph.D. in digital TV broadcasting field. [/FONT]
[FONT=함초롬바탕]I have built nearly all of my audio gear by myself and published 4 books in Korean for building tube/FET amplifiers.[/FONT]
[FONT=함초롬바탕]Anyway, I installed 3 PCBs[/FONT]
[FONT=함초롬바탕]Main PCB: replacing original power board ;[/FONT]
[FONT=함초롬바탕]It has troidal transformer supplying linear power to +5 V, +,-15 V[/FONT]
[FONT=함초롬바탕]Sub PCB and daughter PCB :[/FONT]
[FONT=함초롬바탕]It make linear + 1.0V, 1.1V. 2* 1.8 V and 3.3 V[/FONT]
[FONT=함초롬바탕]( originary it was done by DC-DC converter )[/FONT]
[FONT=함초롬바탕][/FONT][FONT=함초롬바탕]I intended to change 3 crystals to OCXO ( 0.01 PPM );[/FONT]
[FONT=함초롬바탕]I ordered to make 20,25 and 27 Mhz OCXO to nearby Korean manufacturer.[/FONT]
[FONT=함초롬바탕]Each cost about 200 $ !!!! ( minimum order is 5 for each frequency ).[/FONT]
[FONT=함초롬바탕]It takes 4- 6 weeks to deliver. [/FONT]
[FONT=함초롬바탕]I am waiting now.[/FONT]
[FONT=함초롬바탕]For the time being only 20 and 25 MHz are replaced with TCXO ( from digikey )[/FONT]
[FONT=함초롬바탕]27 MHz is placed under main PCB.[/FONT]
[FONT=함초롬바탕][/FONT][FONT=함초롬바탕]I am very happy to the stunning result [/FONT]
[FONT=함초롬바탕]It can compete more than 95 % of Ayre Dx-5 ( my opinion ).[/FONT]
[FONT=함초롬바탕]Picture has vivid color and no noise , edge is sharp.[/FONT]
[FONT=함초롬바탕]I am using JVC X-3 projector for 2D and 3D movies.[/FONT]
[FONT=함초롬바탕]In my humble opinion, my machine is best in the world as far as 3D source player.[/FONT]
[FONT=함초롬바탕]Avatar , alice in Wonderland and IMAX 3D video source is really wonderful with this modified OPPO 93.[/FONT]
[FONT=함초롬바탕]I will keep post again [/FONT]
[FONT=함초롬바탕]It took about 6 months from scratch.[/FONT]
[FONT=함초롬바탕]I am audio and home theater enthusiasts over 30 years have Ph.D. in digital TV broadcasting field. [/FONT]
[FONT=함초롬바탕]I have built nearly all of my audio gear by myself and published 4 books in Korean for building tube/FET amplifiers.[/FONT]
[FONT=함초롬바탕]Anyway, I installed 3 PCBs[/FONT]
[FONT=함초롬바탕]Main PCB: replacing original power board ;[/FONT]
[FONT=함초롬바탕]It has troidal transformer supplying linear power to +5 V, +,-15 V[/FONT]
[FONT=함초롬바탕]Sub PCB and daughter PCB :[/FONT]
[FONT=함초롬바탕]It make linear + 1.0V, 1.1V. 2* 1.8 V and 3.3 V[/FONT]
[FONT=함초롬바탕]( originary it was done by DC-DC converter )[/FONT]
[FONT=함초롬바탕][/FONT][FONT=함초롬바탕]I intended to change 3 crystals to OCXO ( 0.01 PPM );[/FONT]
[FONT=함초롬바탕]I ordered to make 20,25 and 27 Mhz OCXO to nearby Korean manufacturer.[/FONT]
[FONT=함초롬바탕]Each cost about 200 $ !!!! ( minimum order is 5 for each frequency ).[/FONT]
[FONT=함초롬바탕]It takes 4- 6 weeks to deliver. [/FONT]
[FONT=함초롬바탕]I am waiting now.[/FONT]
[FONT=함초롬바탕]For the time being only 20 and 25 MHz are replaced with TCXO ( from digikey )[/FONT]
[FONT=함초롬바탕]27 MHz is placed under main PCB.[/FONT]
[FONT=함초롬바탕][/FONT][FONT=함초롬바탕]I am very happy to the stunning result [/FONT]
[FONT=함초롬바탕]It can compete more than 95 % of Ayre Dx-5 ( my opinion ).[/FONT]
[FONT=함초롬바탕]Picture has vivid color and no noise , edge is sharp.[/FONT]
[FONT=함초롬바탕]I am using JVC X-3 projector for 2D and 3D movies.[/FONT]
[FONT=함초롬바탕]In my humble opinion, my machine is best in the world as far as 3D source player.[/FONT]
[FONT=함초롬바탕]Avatar , alice in Wonderland and IMAX 3D video source is really wonderful with this modified OPPO 93.[/FONT]
[FONT=함초롬바탕]I will keep post again [/FONT]
First an question for Jae Hong Lee .
20Mhz/HDMI oscillator is an quartz resonator (the same 27Mhz one). Did you used an 3,3v 20Mhz TCXO as replacement, or a lower powered oscillator...?
Then a suggestion... You may also try to replace the oscillator for the audio stage (ESS9018), with an 80Mhz, 100Mhz or more... You will have too a pleasant surprise for the sound quality of your mod player...
20Mhz/HDMI oscillator is an quartz resonator (the same 27Mhz one). Did you used an 3,3v 20Mhz TCXO as replacement, or a lower powered oscillator...?
Then a suggestion... You may also try to replace the oscillator for the audio stage (ESS9018), with an 80Mhz, 100Mhz or more... You will have too a pleasant surprise for the sound quality of your mod player...
The picture which shows installing TCXOs to OPPO 93/95 is here ( http://blog.paran.com/blog/detail/postBoard.kth?pmcId=pcaudio&blogDataId=46676002&hrefMark= )
An externally hosted image should be here but it was not working when we last tested it.
EXTREME TOLERANCE OSCILLATORS
Earlier in the thread Coris reported ...
" I just heard the sound difference when used in a DAC a 100ppm oscillator, and a 0.3ppm oscillator (with the same frequency and power supply). I can tell you that is HUGE ..."
Anyone else able to give their experience under similar conditions, where the only change is the oscillator ?
Earlier in the thread Coris reported ...
" I just heard the sound difference when used in a DAC a 100ppm oscillator, and a 0.3ppm oscillator (with the same frequency and power supply). I can tell you that is HUGE ..."
Anyone else able to give their experience under similar conditions, where the only change is the oscillator ?
He also reported picture improvements after replacement of the original oscillator.
I think the results appreciations of a such oscillator improvement have its part of subjectivity... That because is better that one do it himself this change for have own conclusions. And will be so many reports...
Anyway, the improvement in both picture and sound is very real!
