Oppo`s BDP105 - discussions, upgrading, mods... - Page 2 - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 2nd November 2012, 09:29 AM   #11
Coris is offline Coris  Norway
diyAudio Member
 
Join Date: May 2009
Location: Norway
Quote:
Originally Posted by David Gatti View Post
Thanks for your detailed insights Coris.

So in terms of outright audio performance would you say that the BDP-95 is probably superior to the 105?

Which model would you find more amenable to modding/correcting of the design issues?
Even though BDP105 have already some design problems, I think it have some advantages too, over BSDP95 when about modification possibilities. It is more modular, and one do not have to handle with a very big board as in 95 model. The fan less is also another advantage. The analogue PSU it seems to be another big advantage. But I do not know much details about this new PSU in 105. I just think it may be better (the toroid transformer is already)
It may be more easy to take out all that capacitors on the outputs and realize a DC coupling (maybe it will need better final opamps...).
But it could be a problem with those DAC 2 channels which are grounded... Here will be necessary a big mod... But I`m not very sure about the firmware how will handle with those 2 grounded channels, if one will want to use it....
As a conclusion, my option will be at last the 105 model...

Last edited by Coris; 2nd November 2012 at 09:32 AM.
  Reply With Quote
Old 2nd November 2012, 10:48 PM   #12
Coris is offline Coris  Norway
diyAudio Member
 
Join Date: May 2009
Location: Norway
Some interesting clarifications from Oppo (published in AVForum):

Q1. What op-amps are you using in the 105? Are they the same amps used in the 95?
A1. For the BDP-105 we are using the same op-amps as the BDP-95, the LME4562.

Q2. Would you please let me know how the output ESS9018 DAC is configured for the analog stereo outputs and headphone amplifier? For the 83SE and the 95, 4 dacs were dedicated to each stereo and XLR channel for a 4+4 configuration. Is it 2+2 for the XLR channels, 1+1 for the RCA and 1+1 for the headphone amplifier channels? The concern is that the 105 will have inferior analog specs(SNR, THD etc) when compared to the excellent BDP-95.

A2. We want to ensure you that the BDP-105 has the same analog specifications and performance as the BDP-95. This has been a requirement for our design and engineering team from the very beginning of the BDP-105 project. It is also the reason for the new DAC configuration.

In the BDP-105's stereo board design, the 4 pairs of DACs in the ES9018 DAC are allocated as: 1 pair for the RCA outputs, 1 pair for the XLR outputs, and 2 pairs stacked for the headphone amplifier. We had incorrectly stated in the past that 1 DAC pair was used as a ground. This was at one time true as we were working on the engineering, but the final production model which will be shipping to customers will not use a 1 DAC pair for the ground.

During the initial design stage, we simply continued the BDP-95 approach by stacking 4 pairs of DAC for each L/R channel. However due to the complexity brought in by the newly added headphone amp and USB DAC, we could not achieve an ideal PCB layout. The analog specifications became slightly worse than the BDP-95 in this 4 stacked configuration. Our audio engineers and consultants analyzed the problem and made many experiments to further enhance the quality of the analog output stage of the BDP-105. In the end, they decided that the only way to ensure maximum performance was to separate the current-to-voltage conversion stages for each output path. This change enables us to have a much cleaner PCB layout which minimizes interference and crosstalk. It also eliminates the possibility of the load on one output path affecting the other paths. The drawback is that we now lose the benefit of the thermal noise cancellation by stacking 4 DACs. The engineers were able to make up for that by designing an improved power supply, optimizing the filter and drive stages, and beefing up the power and ground paths. The new design costs more than the BDP-95's stereo outputs so it is absolutely not a cost cutting measure. We end up using more high performance components such as op-amps, WIMA and ELNA capacitors.

We try to give conservative, nominal specifications in any literature that we produce, even when the player is known to exceed them. We list the BDP-95's THD+N as -110dB. In our own test it was -114dB. The BDP-105's THD+N is also listed as -110dB. In our own test it was between -115 or -116dB, slightly better than the BDP-95.

The headphone amplifier gets 2 pairs of DAC because its load is much higher than line-level RCA and XLR outputs.


Q3. Are the BDP-105 analog outputs AC or DC coupled? The 95 and 83SE outputs were DC coupled. If the 105 outputs are AC coupled, can you tell us why this is the case?

A3. The BDP-105 analog outputs are AC coupled. The BDP-95 used DC coupled output, and we have had a few rare but annoying compatibility issues with certain amplifiers. Some amplifier may have a DC offset on its input and that has caused issues from popping noises, degraded sound to damaged players. We have selected the components carefully so that the AC coupled output can still produce excellent bass response. The capacitors used are high quality ELNA capacitors. Again this increases cost so we do not make this kind of design changes without a good reason. For the unbalanced RCA stereo output, our consultant 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.

Overall we believe that the BDP-105 sounds slightly better than the BDP-95 due to these design changes. In the end, one has to listen to the player to draw a conclusion. When we first got the ES9018 reference design board a more than two years ago, it measured extremely well but sounded completely "dead". We almost decided against using it and went back to the ES9016 until we actually built our own board to test and found that the ES9018 was indeed better. Audio engineering is a combination of craft and science, and sometimes what is good in theory does not translate to good sound. Our design decisions were based on many years of collective experience from our engineers and consultants, as well as test results from many revisions, and never on cost reduction.


Q4. Would it be possible via a FW update for the user to select in the user menu the maximum power output for the headphone amplifier? The reason i'm asking is that some rather exotic headphones have low sensitivity (electro-statics for example) and need hundreds of milli-watts to come alive, some even requiring a watt or more. A few popular examples would be:

1. Hifiman HE-6 with 83dB/mW @50-ohms impedance.

2. AKG K1000 with 74dB/mW @120-ohms impedance.

A4. Unfortunately it is not possible to adjust the player's maximum power through the headphone amplifier through the firmware. We had toyed with this implementation, but we have found that this could cause loss of resolution and detail when handled through software.

The ability to adjust the maximum power will have to be done through physical hardware (capacitor replacement).

We have tried a wide range of headphones on our players, and based on subjective listening, we have not found a headphone which we felt was not being driven comfortably at the highest volume level when using the headphone amplifier.

It may very well be possible that there are headphones which are incredibly hard to drive, and once encountered, there may be the possibility of swapping out the headphone amplifier which has been modified to better suit the headphone. We will stress that this is a huge "may" as we have never been a fan of after market solutions, but we have done them in the past with the BDP-83 RS232 and BDP-83SE upgrade kits.

Last edited by Coris; 2nd November 2012 at 10:50 PM.
  Reply With Quote
Old 3rd November 2012, 09:47 AM   #13
diyAudio Member
 
David Gatti's Avatar
 
Join Date: Mar 2004
Location: Melbourne, Australia
I'm still not convinced about the cooling of the CPU.
  Reply With Quote
Old 3rd November 2012, 11:05 AM   #14
Coris is offline Coris  Norway
diyAudio Member
 
Join Date: May 2009
Location: Norway
I can also agree... But in the 103 model (picture) one can see a real heat sink over the processor. I suppose the same "construction" is inside 105 too... In this model is not so much place for a bigger heat sink, if necessary...
Until the player is out on the marked and in the hand of some owners, is not so much to be done...
Beta tester reported at some heat is detectable on 105 model. We will see...
  Reply With Quote
Old 3rd November 2012, 04:01 PM   #15
diyAudio Member
 
Join Date: Dec 2008
Quote:
Originally Posted by Coris View Post
Some interesting clarifications from Oppo (published in AVForum):

Q2. Would you please let me know how the output ESS9018 DAC is configured for the analog stereo outputs and headphone amplifier? For the 83SE and the 95, 4 dacs were dedicated to each stereo and XLR channel for a 4+4 configuration.

A2. We want to ensure you that the BDP-105 has the same analog specifications and performance as the BDP-95.

In the BDP-105's stereo board design, the 4 pairs of DACs in the ES9018 DAC are allocated as: 1 pair for the RCA outputs, 1 pair for the XLR outputs, and 2 pairs stacked for the headphone amplifier.

During the initial design stage, we simply continued the BDP-95 approach by stacking 4 pairs of DAC for each L/R channel. However due to the complexity brought in by the newly added headphone amp and USB DAC, we could not achieve an ideal PCB layout. The analog specifications became slightly worse than the BDP-95 in this 4 stacked configuration. Our audio engineers and consultants analyzed the problem and made many experiments to further enhance the quality of the analog output stage of the BDP-105. In the end, they decided that the only way to ensure maximum performance was to separate the current-to-voltage conversion stages for each output path. This change enables us to have a much cleaner PCB layout which minimizes interference and crosstalk. It also eliminates the possibility of the load on one output path affecting the other paths. The drawback is that we now lose the benefit of the thermal noise cancellation by stacking 4 DACs. The engineers were able to make up for that by designing an improved power supply, optimizing the filter and drive stages, and beefing up the power and ground paths. The new design costs more than the BDP-95's stereo outputs so it is absolutely not a cost cutting measure. We end up using more high performance components such as op-amps, WIMA and ELNA capacitors.




Q3. Are the BDP-105 analog outputs AC or DC coupled? The 95 and 83SE outputs were DC coupled. If the 105 outputs are AC coupled, can you tell us why this is the case?

A3. The BDP-105 analog outputs are AC coupled. The BDP-95 used DC coupled output, and we have had a few rare but annoying compatibility issues with certain amplifiers.

Overall we believe that the BDP-105 sounds slightly better than the BDP-95 due to these design changes...

... Audio engineering is a combination of craft and science, and sometimes what is good in theory does not translate to good sound.
Thanks for posting this info.

I would like a digital source that can play SACD - without a fan. So I had/have high hopes for the Oppo 105.

Do you know if the Oppo 95 or 105 upsamples red book CD's to 32 bits ?

For the 105, What are your opinions on upgrading the output coupling caps ?
Because of space limitations, it seems there are few options for cap choices.
.
  Reply With Quote
Old 3rd November 2012, 07:39 PM   #16
Coris is offline Coris  Norway
diyAudio Member
 
Join Date: May 2009
Location: Norway
Quote:
Originally Posted by Uunderhill View Post
Thanks for posting this info.

I would like a digital source that can play SACD - without a fan. So I had/have high hopes for the Oppo 105.

Do you know if the Oppo 95 or 105 upsamples red book CD's to 32 bits ?

For the 105, What are your opinions on upgrading the output coupling caps ?
Because of space limitations, it seems there are few options for cap choices.
.
I`m quite sceptic about it is happen up sampling to 32 bits inside the player... It may be possible, but nobody knows, but the producer...
Art least the specifications of 95/105 are about 24 bit (standard).
But you can do it by your self this... It take a little time, but the result is very good.
I will tell you how I do it:
I rip the CD into my editing software (Audition). Correct the level for each file to a right one (usually into -1dB). This is my standard. Up sampling the 44100/16bit file to 176400Hz /32bit (100% quality). Apply or not Channels Phase correction.
Convert the file to Flac - 176,4Khz/24 bit. Play it through my player (95).
Top result!
You can be amazed about how much information/fidelity is encoded in to the standard CD files and one do not hear it when it plays the CD at standard sampling/bit.

About the capacitors (AC coupling), I think is just wasting time and money with upgrading to another ones. Those capacitors do not have to be there!
Just remove all and establish DC coupling.
Oppo explanations it seems to me as stupid or misleading. They justify the AC coupling with few cases when were reported (maybe) problems because offset at the input of those types amplifiers ???!!!
A whole production and design of a new player model is adapted to only few cases where an amplifier input offset have disturbed the DC coupled output of the plyer.... This it looks to me as very strange.
We know all that BDP95 have an DC coupling and is very well this way. So it have to be! If Oppo should mount an load resistor at the end of the DC coupled output it will prevent any offset caused by the next connection to that output. Not AC coupling is the solution!
As a conclusion, I will suggest you to forget the upgrading of the output channels capacitors on BDP105 (when you will have it). Just remove it all.
You may check first if your amplifier have no any offset on its input (this is not usually at all!). You may also check (before this operation) if the offset of the final opamp (before the AC coupling) is at the reasonable level (best 0,0V). About just this I doubt seriously: that Oppo have succeed to have out of production lines an final stage opamp with 0v offset. It looks to me that that because they chosen AC coupling, to fix out the high offset at the final opamp in DC coupling, for this new model of their player...
But the final conclusion will be when we will have that player on the bench....

Last edited by Coris; 3rd November 2012 at 07:44 PM.
  Reply With Quote
Old 3rd November 2012, 07:45 PM   #17
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Coris, IF you take the caps out, you WILL get DC offset.
  Reply With Quote
Old 3rd November 2012, 09:44 PM   #18
Coris is offline Coris  Norway
diyAudio Member
 
Join Date: May 2009
Location: Norway
Quote:
Originally Posted by john curl View Post
Coris, IF you take the caps out, you WILL get DC offset.
This have to be checked out for sure... We know that BDP95 is DC coupled... That offset can very well be fix it. I`ve done it in my design (mod). There are many ways, and one of those is also recommended in data sheet of ESS9018.
For the moment, we (the potential users) do not know design details about how the offset problem is treated in the new player... How much that is, what design is used, etc. We will see... and conclude then.
I know that is not easy to control such offset in production of thousands of PCBs, when the components are not very high end, for a product which it have to have a quite low price, and so on...

I think that maybe for the moment is more reasonable to slow down the "dispute", waiting for the player to come out...

Last edited by Coris; 3rd November 2012 at 09:56 PM.
  Reply With Quote
Old 4th November 2012, 03:20 AM   #19
diyAudio Member
 
David Gatti's Avatar
 
Join Date: Mar 2004
Location: Melbourne, Australia
I can fully understand why Oppo have not DC coupled the output - they have to make their equipment fool proof.
If users want to bypass or replace the output caps with something superior (and I'm one of them) that is done at their own risk.

Does anyone have details on the output caps as it's hard to tell from the pics? Are they electrolytic and what is their value?
  Reply With Quote
Old 4th November 2012, 03:44 AM   #20
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
just making a dac that has no DC on the output is pretty foolproof... not that hard when youve got a balanced dac either
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
OPPO 93 and OPPO 95 - A warning. sandyK Digital Source 3 26th January 2012 06:53 AM
Discussions about your favorite or DIYD/T-amp v-bro Class D 0 13th January 2009 08:37 AM
Class D discussions mskeete Class D 16 19th March 2004 06:27 AM
Discussions on Balenced Amplifers theChris Chip Amps 24 6th January 2004 02:40 PM
Do opamps discussions also have to take place here? Bricolo Chip Amps 3 27th April 2003 08:39 PM


New To Site? Need Help?

All times are GMT. The time now is 04:42 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2